Mixed Plasmodium falciparum infections were common in four areas of the Brazilian Amazon region. Molecular diagnosis found 73% of infections were single P. falciparum infections, while 27% were mixed infections, mostly double infections. Mixed infections were associated with weaker clinical malaria symptoms like lower rates of fever and headache compared to single P. falciparum infections. The study highlights the need for improved malaria diagnosis to better understand mixed infections and their impact on disease severity.
This study evaluated the frequency of asymptomatic Plasmodium carriers (APCs) among blood donors in four blood banks in the Brazilian Amazon region. Blood samples from 400 donors who passed screening were tested using PCR to detect Plasmodium DNA. The positivity rate varied from 1-3% between blood banks, with an overall rate of 2.3%. All positive samples contained mixed infections of P. vivax and P. falciparum. While screening methods used by the blood banks did not detect the infections, PCR revealed its superiority for detecting low levels of parasites. The results emphasize the need to improve screening for APCs in blood banks in malaria endemic areas to control transfusion-transmitted malaria.
Type specific persistence of high risk human papillomavirus (HPV) as indicato...Alberto Cuadrado
Objectives To investigate the role of human
papillomavirus (HPV) in the development of cervical
neoplasia in women with no previous cervical
cytological abnormalities; whether the presence of
virus DNA predicts development of squamous
intraepithelial lesion; and whether the risk of incident
squamous intraepithelial lesions differs with repeated
detection of the same HPV type versus repeated
detection of different types.
Design Population based prospective cohort study.
Setting General population in Copenhagen,
Denmark.
Participants 10 758 women aged 2029 years
followed up for development of cervical cytological
abnormalities; 370 incident cases were detected (40
with atypical squamous cells of undetermined
significance, 165 with low grade squamous
intraepithelial lesions, 165 with high grade squamous
intraepithelial lesions).
Main outcome measures Results of cervical smear
tests and cervical swabs at enrolment and at the
second examination about two years later.
Results Compared with women who were negative
for human papillomavirus at enrolment, those with
positive results had a significantly increased risk at
follow up of having atypical cells (odds ratio 3.2, 95%
confidence interval 1.3 to 7.9), low grade lesions (7.5,
4.8 to 11.7), or high grade lesions (25.8, 15.3 to 43.6).
Similarly, women who were positive for HPV at the
second examination had a strongly increased risk of
low (34.3, 17.6 to 67.0) and high grade lesions (60.7,
25.5 to 144.0). For high grade lesions the risk was
strongly increased if the same virus type was present
at both examinations (813.0, 168.2 to 3229.2).
Conclusions Infection with human papillomavirus
precedes the development of low and high grade
squamous intraepithelial lesions. For high grade
lesions the risk is greatest in women positive for the
same type of HPV on repeated testing.
Papillomavirus research update: highlights of the Barcelona HPV 2000 internat...Alberto Cuadrado
This document summarizes highlights from the 18th International Papillomavirus Conference held in Barcelona, Spain in July 2000. It discusses several key topics:
1) Epidemiological studies presented data on HPV prevalence by age and risk factors like oral contraceptive use.
2) Studies of HPV serology found correlations between antibody levels and sexual behavior or HPV infection status.
3) Research on potential cofactors in cervical cancer like chlamydia infection presented both supporting and non-supporting evidence for their role in carcinogenesis.
The Natural History of Type-specific Human Papillomavirus Infections in Femal...Alberto Cuadrado
This study examined the natural history of type-specific HPV infections in female university students over 24 months. Key findings include:
- The incidence rates of acquiring high-risk or low-risk HPV infections were similar at around 14 and 12 cases per 1000 women-months, respectively.
- HPV-16, -51, and -84 had the highest rates of new acquisition at around 5, 3, and 4 cases per 1000 women-months, respectively.
- HPV-16 infections persisted the longest on average at 18 months, followed by HPV-31 and HPV-53 at around 14-15 months. HPV-6 and HPV-84 cleared fastest on average in under 10 months.
- After
Genotyping of 27 Human Papillomavirus Types by Using L1 Consensus PCR Product...Alberto Cuadrado
Amplification of human papillomavirus (HPV) DNA by L1 consensus primer systems (e.g., MY09/11 or
GP51/61) can detect as few as 10 to 100 molecules of HPV targets from a genital sample. However, genotype
determination by dot blot hybridization is laborious and requires at least 27 separate hybridizations for
substantive HPV-type discrimination. A reverse blot method was developed which employs a biotin-labeled
PCR product hybridized to an array of immobilized oligonucleotide probes. By the reverse blot strip analysis,
genotype discrimination of multiple HPV types can be accomplished in a single hybridization and wash cycle.
Twenty-seven HPV probe mixes, two control probe concentrations, and a single reference line were immobilized
to 75- by 6-mm nylon strips. Each individual probe line contained a mixture of two bovine serum albuminconjugated
oligonucleotide probes specific to a unique HPV genotype. The genotype spectrum discriminated on
this strip includes the high-risk, or cancer-associated, HPV genotypes 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 55,
56, 58, 59, 68 (ME180), MM4 (W13B), MM7 (P291), and MM9 (P238A) and the low-risk, or non-cancerassociated,
genotypes 6, 11, 40, 42, 53, 54, 57, 66, and MM8 (P155). In addition, two concentrations of b-globin
probes allowed for assessment of individual specimen adequacy following amplification. We have evaluated the
performance of the strip method relative to that of a previously reported dot blot format (H. M. Bauer et al.,
p. 132–152, in C. S. Herrington and J. O. D. McGee (ed.), Diagnostic Molecular Pathology: a Practical Approach,
(1992), by testing 328 cervical swab samples collected in Digene specimen transport medium (Digene Diagnostics,
Silver Spring, Md.). We show excellent agreement between the two detection formats, with 92%
concordance for HPV positivity (kappa 5 0.78, P < 0.001). Nearly all of the discrepant HPV-positive samples
resulted from weak signals and can be attributed to sampling error from specimens with low concentrations
(<1 copy/ml) of HPV DNA. The primary advantage of the strip-based detection system is the ability to rapidly
genotype HPVs present in genital samples with high sensitivity and specificity, minimizing the likelihood of
misclassification.
Prospects for primary prevention of cervical cancer in developing countriesAlberto Cuadrado
This document discusses prospects for primary prevention of cervical cancer in developing countries through HPV vaccination. It notes that HPV types 16 and 18 cause the majority of cervical cancers worldwide. Vaccines against HPV, particularly virus-like particle vaccines, show promise in preventing HPV infection and progression to cervical cancer. While efficacy trials of HPV vaccines are underway, effectiveness trials under field conditions in developing countries are also needed to demonstrate the real-world impact of HPV vaccination programs in reducing cervical cancer incidence and mortality over prolonged follow-up periods of 20 years or more. Such effectiveness trials could help accelerate adoption of HPV vaccination in populations that bear the greatest cervical cancer burden.
This study investigated the relationship between variants of the glycophorin B (GPB) gene and susceptibility to Plasmodium falciparum infection in the Brazilian Amazon. The researchers found that individuals carrying the GYPB*S allele were more likely to be infected with P. falciparum than those without this allele. Sequence analysis of GYPB also suggested it has been under natural selection due to malaria. This study provides evidence that genetic variation in GPB receptor influences the ability of P. falciparum to invade red blood cells in this population.
frequency of cryptococcus species and varieties in méxicoIPN
This study analyzed 211 Cryptococcus strains isolated from patients in Mexico City hospitals between 1989-1998. C. neoformans was the dominant species isolated (97.15%), followed by C. albidus and C. uniguttulatus. Most strains were isolated from cerebral spinal fluid (92.5%) and AIDS was the main predisposing factor (85%). The disease was found to predominantly affect males (87.3%) in their third (33.8%) and fourth (37.5%) decades of life. When compared to other Latin American countries, the isolation frequency of C. neoformans var. neoformans and var. gattii in Mexico was most similar to Brazil.
This study evaluated the frequency of asymptomatic Plasmodium carriers (APCs) among blood donors in four blood banks in the Brazilian Amazon region. Blood samples from 400 donors who passed screening were tested using PCR to detect Plasmodium DNA. The positivity rate varied from 1-3% between blood banks, with an overall rate of 2.3%. All positive samples contained mixed infections of P. vivax and P. falciparum. While screening methods used by the blood banks did not detect the infections, PCR revealed its superiority for detecting low levels of parasites. The results emphasize the need to improve screening for APCs in blood banks in malaria endemic areas to control transfusion-transmitted malaria.
Type specific persistence of high risk human papillomavirus (HPV) as indicato...Alberto Cuadrado
Objectives To investigate the role of human
papillomavirus (HPV) in the development of cervical
neoplasia in women with no previous cervical
cytological abnormalities; whether the presence of
virus DNA predicts development of squamous
intraepithelial lesion; and whether the risk of incident
squamous intraepithelial lesions differs with repeated
detection of the same HPV type versus repeated
detection of different types.
Design Population based prospective cohort study.
Setting General population in Copenhagen,
Denmark.
Participants 10 758 women aged 2029 years
followed up for development of cervical cytological
abnormalities; 370 incident cases were detected (40
with atypical squamous cells of undetermined
significance, 165 with low grade squamous
intraepithelial lesions, 165 with high grade squamous
intraepithelial lesions).
Main outcome measures Results of cervical smear
tests and cervical swabs at enrolment and at the
second examination about two years later.
Results Compared with women who were negative
for human papillomavirus at enrolment, those with
positive results had a significantly increased risk at
follow up of having atypical cells (odds ratio 3.2, 95%
confidence interval 1.3 to 7.9), low grade lesions (7.5,
4.8 to 11.7), or high grade lesions (25.8, 15.3 to 43.6).
Similarly, women who were positive for HPV at the
second examination had a strongly increased risk of
low (34.3, 17.6 to 67.0) and high grade lesions (60.7,
25.5 to 144.0). For high grade lesions the risk was
strongly increased if the same virus type was present
at both examinations (813.0, 168.2 to 3229.2).
Conclusions Infection with human papillomavirus
precedes the development of low and high grade
squamous intraepithelial lesions. For high grade
lesions the risk is greatest in women positive for the
same type of HPV on repeated testing.
Papillomavirus research update: highlights of the Barcelona HPV 2000 internat...Alberto Cuadrado
This document summarizes highlights from the 18th International Papillomavirus Conference held in Barcelona, Spain in July 2000. It discusses several key topics:
1) Epidemiological studies presented data on HPV prevalence by age and risk factors like oral contraceptive use.
2) Studies of HPV serology found correlations between antibody levels and sexual behavior or HPV infection status.
3) Research on potential cofactors in cervical cancer like chlamydia infection presented both supporting and non-supporting evidence for their role in carcinogenesis.
The Natural History of Type-specific Human Papillomavirus Infections in Femal...Alberto Cuadrado
This study examined the natural history of type-specific HPV infections in female university students over 24 months. Key findings include:
- The incidence rates of acquiring high-risk or low-risk HPV infections were similar at around 14 and 12 cases per 1000 women-months, respectively.
- HPV-16, -51, and -84 had the highest rates of new acquisition at around 5, 3, and 4 cases per 1000 women-months, respectively.
- HPV-16 infections persisted the longest on average at 18 months, followed by HPV-31 and HPV-53 at around 14-15 months. HPV-6 and HPV-84 cleared fastest on average in under 10 months.
- After
Genotyping of 27 Human Papillomavirus Types by Using L1 Consensus PCR Product...Alberto Cuadrado
Amplification of human papillomavirus (HPV) DNA by L1 consensus primer systems (e.g., MY09/11 or
GP51/61) can detect as few as 10 to 100 molecules of HPV targets from a genital sample. However, genotype
determination by dot blot hybridization is laborious and requires at least 27 separate hybridizations for
substantive HPV-type discrimination. A reverse blot method was developed which employs a biotin-labeled
PCR product hybridized to an array of immobilized oligonucleotide probes. By the reverse blot strip analysis,
genotype discrimination of multiple HPV types can be accomplished in a single hybridization and wash cycle.
Twenty-seven HPV probe mixes, two control probe concentrations, and a single reference line were immobilized
to 75- by 6-mm nylon strips. Each individual probe line contained a mixture of two bovine serum albuminconjugated
oligonucleotide probes specific to a unique HPV genotype. The genotype spectrum discriminated on
this strip includes the high-risk, or cancer-associated, HPV genotypes 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 55,
56, 58, 59, 68 (ME180), MM4 (W13B), MM7 (P291), and MM9 (P238A) and the low-risk, or non-cancerassociated,
genotypes 6, 11, 40, 42, 53, 54, 57, 66, and MM8 (P155). In addition, two concentrations of b-globin
probes allowed for assessment of individual specimen adequacy following amplification. We have evaluated the
performance of the strip method relative to that of a previously reported dot blot format (H. M. Bauer et al.,
p. 132–152, in C. S. Herrington and J. O. D. McGee (ed.), Diagnostic Molecular Pathology: a Practical Approach,
(1992), by testing 328 cervical swab samples collected in Digene specimen transport medium (Digene Diagnostics,
Silver Spring, Md.). We show excellent agreement between the two detection formats, with 92%
concordance for HPV positivity (kappa 5 0.78, P < 0.001). Nearly all of the discrepant HPV-positive samples
resulted from weak signals and can be attributed to sampling error from specimens with low concentrations
(<1 copy/ml) of HPV DNA. The primary advantage of the strip-based detection system is the ability to rapidly
genotype HPVs present in genital samples with high sensitivity and specificity, minimizing the likelihood of
misclassification.
Prospects for primary prevention of cervical cancer in developing countriesAlberto Cuadrado
This document discusses prospects for primary prevention of cervical cancer in developing countries through HPV vaccination. It notes that HPV types 16 and 18 cause the majority of cervical cancers worldwide. Vaccines against HPV, particularly virus-like particle vaccines, show promise in preventing HPV infection and progression to cervical cancer. While efficacy trials of HPV vaccines are underway, effectiveness trials under field conditions in developing countries are also needed to demonstrate the real-world impact of HPV vaccination programs in reducing cervical cancer incidence and mortality over prolonged follow-up periods of 20 years or more. Such effectiveness trials could help accelerate adoption of HPV vaccination in populations that bear the greatest cervical cancer burden.
This study investigated the relationship between variants of the glycophorin B (GPB) gene and susceptibility to Plasmodium falciparum infection in the Brazilian Amazon. The researchers found that individuals carrying the GYPB*S allele were more likely to be infected with P. falciparum than those without this allele. Sequence analysis of GYPB also suggested it has been under natural selection due to malaria. This study provides evidence that genetic variation in GPB receptor influences the ability of P. falciparum to invade red blood cells in this population.
frequency of cryptococcus species and varieties in méxicoIPN
This study analyzed 211 Cryptococcus strains isolated from patients in Mexico City hospitals between 1989-1998. C. neoformans was the dominant species isolated (97.15%), followed by C. albidus and C. uniguttulatus. Most strains were isolated from cerebral spinal fluid (92.5%) and AIDS was the main predisposing factor (85%). The disease was found to predominantly affect males (87.3%) in their third (33.8%) and fourth (37.5%) decades of life. When compared to other Latin American countries, the isolation frequency of C. neoformans var. neoformans and var. gattii in Mexico was most similar to Brazil.
The causal relation between human papillomavirus and cervical cancerAlberto Cuadrado
J Clin Pathol 2002;55:244–265
The causal role of human papillomavirus infections in
cervical cancer has been documented beyond
reasonable doubt. The association is present in virtually
all cervical cancer cases worldwide. It is the right time
for medical societies and public health regulators to
consider this evidence and to define its preventive and
clinical implications. A comprehensive review of key
studies and results is presented.
Epidemiologic Classification of Human Papillomavirus Types Associated with Ce...Alberto Cuadrado
background
Infection with human papilloma virus (HPV) is the main cause of cervical cancer, but
the risk associated with the various HPV types has not been adequately assessed.
methods
We pooled data from 11 case–control studies from nine countries involving 1918 women
with histologically confirmed squamous-cell cervical cancer and 1928 control women.
A common protocol and questionnaire were used. Information on risk factors was
obtained by personal interviews, and cervical cells were collected for detection of HPV
DNA and typing in a central laboratory by polymerase-chain-reaction–based assays
(with MY09/MY11 and GP5+/6+ primers).
results
HPV DNA was detected in 1739 of the 1918 patients with cervical cancer (90.7 percent)
and in 259 of the 1928 control women (13.4 percent). With the GP5+/6+ primer, HPV
DNA was detected in 96.6 percent of the patients and 15.6 percent of the controls. The
most common HPV types in patients, in descending order of frequency, were types 16,
18, 45, 31, 33, 52, 58, and 35. Among control women, types 16, 18, 45, 31, 6, 58, 35, and
33 were the most common. For studies using the GP5+/6+ primer, the pooled odds ratio
for cervical cancer associated with the presence of any HPV was 158.2 (95 percent
confidence interval, 113.4 to 220.6). The odds ratios were over 45 for the most common
and least common HPV types. Fifteen HPV types were classified as high-risk types
(16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82); 3 were classified as probable
high-risk types (26, 53, and 66); and 12 were classified as low-risk types (6, 11, 40,
42, 43, 44, 54, 61, 70, 72, 81, and CP6108). There was good agreement between our epidemiologic
classification and the classification based on phylogenetic grouping.
conclusions
In addition to HPV types 16 and 18, types 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73,
and 82 should be considered carcinogenic, or high-risk, types, and types 26, 53, and 66
should be considered probably carcinogenic.
Plasma levels of circulating nucleic acids (CNAs) were significantly higher in patients with Plasmodium vivax malaria compared to healthy donors. CNAs levels strongly correlated with clinical markers of malaria morbidity, including fever and thrombocytopenia. Higher CNAs levels were also associated with a more severe clinical presentation based on a scoring system. These findings suggest that CNAs have potential as sensitive biomarkers for assessing severity of P. vivax malaria infections.
Citrobacter frendii infections in ReptilesCelise Taylor
This document summarizes information about Citrobacter frendii infections in humans and reptiles. It discusses the bacterium's history, associated diseases like pneumonia and meningitis, modes of transmission including person-to-person and through animal hosts like turtles, current treatment approaches using antimicrobial agents, and prevalence based on various studies showing it has infected many humans and captive reptiles. Personal experience is also shared treating infected sliders with topical antimicrobial treatments.
Vancomycin-resistant Staphylococcus aureus (VRSA) is a serious antibiotic-resistant bacterial infection. Overuse and misuse of antibiotics has encouraged the emergence of resistant strains like VRSA. VRSA was first identified in the 1990s and cases have been reported worldwide since then. VRSA poses a major health risk as it can be difficult to treat and has the potential to spread rapidly internationally through human travel and contact. Proper infection control practices and antibiotic stewardship are important to prevent the further emergence and spread of VRSA.
Characterization of Mycobacterium Tuberculosis Complex Strains: A Multicenter...CrimsonpublishersCJMI
Characterization of Mycobacterium Tuberculosis Complex Strains: A Multicenter Retrospective Greek Study by Lamprini Gkaravela in Cohesive Journal of Microbiology & Infectious Disease
Study of the Seroprevalence of Anti-Leptospirosis Antibodies in Subjects in T...IIJSRJournal
Leptospirosis is a tropical and subtropical zoonotic disease culminating as a serious public health problem worldwide, apparently existing as co-infections with various other unrelated diseases, such as malaria. It is caused by spiral bacteria and the main vectors of which are rodents. These bacteria have various survival mechanisms in the environment allowing them to carry out their infectious cycle within their host organisms. The pathophysiological mechanisms pertaining to leptospirosis is still not understood in full and mis or underdiagnosed.
A cross-sectional descriptive study was carried out in three different localities in Niamey where respondents were screened for to demonstrate transmission to humans. Indirect ELISA method as a laboratory diagnostic or screening toll is used by utilizing leptospiral-specific IgG from serum samples of the respondents.
Results from the study showed that 11 people are found to be positive for leptospirosis (with a seroprevalence of 2.75%) with a strong tendency in the slaughterhouse workers which presents a fairly high risk compared to the other localities of the study. Indeed, the different areas/localities of this pilot study do not present the same level of risk because they are not subject to the same risk associated factors. In this vein, we have 87.6% of population exposed to the presence of rats, 48% are in contact with animals, 38.6% live in homes near water and 12.9% go swimming.
This study made it possible, on the one hand, to highlight the transmission of leptospirosis from animals to humans and, on the other hand, to draw attention to the involvement of the various identified risk factors.
This study analyzed 182 pediatric patients under 14 years old with Staphylococcus aureus infections from 3 hospitals in Medellin, Colombia between 2008-2010. 41.4% of patients were under 1 year old. The most common infections were skin and soft tissue infections. Patients with methicillin-resistant S. aureus infections were more likely to have attended daycare centers or taken previous antibiotics. Sixteen different clonal complexes were identified among the isolates, with methicillin-susceptible S. aureus strains showing more diversity. The most common staphylococcal cassette chromosome mec type was IVc, which was linked to Panton-Valentine leukocidin genes. This prevalence of S. aureus infections in
1) The document provides an overview of malaria including epidemiology, etiology, pathogenesis, clinical manifestations, diagnosis, treatment and prevention.
2) Malaria remains a major global health problem, transmitted by the bite of infected Anopheles mosquitoes. Plasmodium falciparum causes the largest disease burden.
3) Clinical presentation varies depending on malaria species, immunity, and transmission intensity. Uncomplicated malaria typically involves fever, while severe malaria can involve organ dysfunction. Diagnosis involves microscopy or rapid tests to detect the parasite. Treatment depends on malaria species and disease severity.
Malaria and Babesiosis co-infectionpptAKWAOWO OROK
This document outlines a proposed seminar series titled "Babesia with Plasmodium Coinfection". The three seminars will cover: 1) The biology of Babesia and Plasmodium parasites, their life cycles, and epidemiology of babesiosis and malaria. 2) Ecological kinetics and immunology of coinfection. 3) Pathophysiology, diagnosis, and treatment of Babesia and Plasmodium infection. The first seminar will focus on the similarities and differences between Babesia and Plasmodium, their life cycles, transmission, geographic distribution, and impact on humans and livestock.
This study aimed to estimate the prevalence of community-onset Clostridium difficile infection (CO-CDI) and identify associated risk factors. The researchers found that 58 cases of CO-CDI were diagnosed among 418,000 people, representing a prevalence of 1.29 per 10,000. Established risk factors like recent antibiotic use were present in 46.3% of cases. However, 16.7% had no known risk factors, suggesting CDI should be considered even without them. Non-established factors like outpatient hospital exposure and travel were also associated with CO-CDI. Larger prospective studies are still needed to further investigate these potential risk factors.
Ebola virus disease - A comprehensive reviewpharmaindexing
This document provides a comprehensive review of Ebola virus disease (EVD). It discusses that EVD is caused by infection with one of five subtypes of the Ebola virus, four of which have caused disease in humans. The virus is believed to originate from fruit bats and then spreads between humans through direct contact with bodily fluids. While there is no approved vaccine or treatment, several are currently being tested. The largest Ebola outbreak on record began in 2014 and spread across Guinea, Liberia, Sierra Leone and Nigeria, resulting in over 1,000 deaths.
RELAPSES AND RECURRENT MALARIA - NEHA PILLAI VINOD, RA1841002010087, DEPARTME...neha1309
This document discusses relapse in malaria. It defines relapse as the return of malaria symptoms after apparent cure of the disease. Relapse is caused by dormant liver stages called hypnozoites in Plasmodium vivax and Plasmodium ovale infections. Several theories are presented to explain the mechanisms of relapse, and the latent tissue stage/hypnozoite theory best accounts for observed relapse patterns. Factors that influence relapse include the number of sporozoites inoculated, acquisition of blood stage immunity, and differences between tropical and temperate regions. The hypnozoite is described as an exoerythrocytic schizont in the liver that causes delayed primary development and relapses.
Gram-negative bacteria commonly cause nosocomial infections like pneumonia and bloodstream infections in debilitated patients. Enterobacteriaceae are the most frequent causes, while non-fermenters like Pseudomonas and Acinetobacter predominate in critically ill patients. Mortality from gram-negative infections remains high, especially with certain multidrug-resistant pathogens. Inappropriate antibiotic therapy, which can include incorrect dosing or use when not indicated, increases morbidity, mortality and resistance. Extended-spectrum beta-lactamases and AmpC beta-lactamases are important resistance mechanisms in key pathogens like K. pneumoniae and Enterobacter species. Carbapenems remain the preferred treatment for infections caused by extended
This document provides a summary of Tibor Farkas's qualifications and experience. He has over 20 years of experience in microbiology and virology research, particularly regarding enteric viruses, at Cincinnati Children's Hospital and previously in Hungary. His research accomplishments include the discovery and characterization of several novel viral pathogens. He has strong skills in laboratory techniques, experimental design, and leadership.
Dr. Kurt Stevenson - Antimicrobial Resistance Surveillance and Management in ...John Blue
Antimicrobial Resistance Surveillance and Management in Hospital and Community Settings - Issues for Human Population Medicine - Dr. Kurt Stevenson, The Ohio State University Medical Center, from the 2012 NIAA One Health Approach to Antimicrobial Resistance and Use Symposium, October 26-27, 2012, Columbus, OH, USA.
More presentations at:
http://www.trufflemedia.com/agmedia/conference/2012-one-health-to-approach-antimicrobial-resistance-and-use
Martin Chang, MBBE final report, 2012_08_21Martin Chang
This document summarizes key information about developing an effective blood-stage malaria vaccine, including:
1) Existing vaccines like RTS,S have shown only partial effectiveness, so more effective vaccines are still needed.
2) The malaria parasite has different life stages, and vaccines target different stages. This report focuses on blood-stage vaccines.
3) Effective immune mechanisms against blood-stage parasites include antibody-dependent cellular inhibition (ADCI) and antibody-dependent respiratory burst (ADRB), but these have not been fully induced by existing vaccines.
Babesiosis, caused by infection with intra erythrocytic parasites of the genus Babesia, is one of the most common infections of free living animals worldwide and is gaining increasing interest as an emerging zoonosis in humans. this is a detailed study on this ......considering all the facts such as definition , management, parthenogenesis, diagnosis, treatment, prevention , etc
please comment
thank u
This document is the preface to the book "Salmonella: Methods and Protocols, Second Edition". It summarizes advances in Salmonella research since the first edition, including new methods for detecting and treating Salmonella infections, overcoming antibiotic resistance, vaccine development using nanotechnology, and using genetically modified Salmonella as delivery vectors for cancer therapies. The second edition features new chapters covering molecular detection and identification of Salmonella, quantitative proteomics to identify host factors in Salmonella infection, determining antibiotic resistance, and various microscopy and modeling methods. The preface expresses gratitude to the contributors for sharing their expertise and to the publisher.
Tendances Futures du Web - GTI780 & MTI780 - ETS - A09Claude Coulombe
Présentation sur les tendances futures du Web dans le cadre du cours combiné GTI780 / MTI780, Sujets spéciaux en TI, donné par Claude Coulombe, à l'Ecole de technologie supérieure, Montréal, Automne 2009
1. The study characterized antibody responses to Plasmodium falciparum invasion ligands EBA-140 and EBA-181 in individuals from malaria-endemic areas of Brazil and Cameroon.
2. Responses differed between populations, with African individuals strongly reacting to most EBA fragments while Brazilian individuals from Mato Grosso reacted weakly and those from the Amazon had elevated but lower responses than Africans.
3. When compared to responses against other malaria proteins, the Brazilian population appeared to have more variable ability to recognize P. falciparum invasion ligands, distinct from the African population.
The causal relation between human papillomavirus and cervical cancerAlberto Cuadrado
J Clin Pathol 2002;55:244–265
The causal role of human papillomavirus infections in
cervical cancer has been documented beyond
reasonable doubt. The association is present in virtually
all cervical cancer cases worldwide. It is the right time
for medical societies and public health regulators to
consider this evidence and to define its preventive and
clinical implications. A comprehensive review of key
studies and results is presented.
Epidemiologic Classification of Human Papillomavirus Types Associated with Ce...Alberto Cuadrado
background
Infection with human papilloma virus (HPV) is the main cause of cervical cancer, but
the risk associated with the various HPV types has not been adequately assessed.
methods
We pooled data from 11 case–control studies from nine countries involving 1918 women
with histologically confirmed squamous-cell cervical cancer and 1928 control women.
A common protocol and questionnaire were used. Information on risk factors was
obtained by personal interviews, and cervical cells were collected for detection of HPV
DNA and typing in a central laboratory by polymerase-chain-reaction–based assays
(with MY09/MY11 and GP5+/6+ primers).
results
HPV DNA was detected in 1739 of the 1918 patients with cervical cancer (90.7 percent)
and in 259 of the 1928 control women (13.4 percent). With the GP5+/6+ primer, HPV
DNA was detected in 96.6 percent of the patients and 15.6 percent of the controls. The
most common HPV types in patients, in descending order of frequency, were types 16,
18, 45, 31, 33, 52, 58, and 35. Among control women, types 16, 18, 45, 31, 6, 58, 35, and
33 were the most common. For studies using the GP5+/6+ primer, the pooled odds ratio
for cervical cancer associated with the presence of any HPV was 158.2 (95 percent
confidence interval, 113.4 to 220.6). The odds ratios were over 45 for the most common
and least common HPV types. Fifteen HPV types were classified as high-risk types
(16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82); 3 were classified as probable
high-risk types (26, 53, and 66); and 12 were classified as low-risk types (6, 11, 40,
42, 43, 44, 54, 61, 70, 72, 81, and CP6108). There was good agreement between our epidemiologic
classification and the classification based on phylogenetic grouping.
conclusions
In addition to HPV types 16 and 18, types 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73,
and 82 should be considered carcinogenic, or high-risk, types, and types 26, 53, and 66
should be considered probably carcinogenic.
Plasma levels of circulating nucleic acids (CNAs) were significantly higher in patients with Plasmodium vivax malaria compared to healthy donors. CNAs levels strongly correlated with clinical markers of malaria morbidity, including fever and thrombocytopenia. Higher CNAs levels were also associated with a more severe clinical presentation based on a scoring system. These findings suggest that CNAs have potential as sensitive biomarkers for assessing severity of P. vivax malaria infections.
Citrobacter frendii infections in ReptilesCelise Taylor
This document summarizes information about Citrobacter frendii infections in humans and reptiles. It discusses the bacterium's history, associated diseases like pneumonia and meningitis, modes of transmission including person-to-person and through animal hosts like turtles, current treatment approaches using antimicrobial agents, and prevalence based on various studies showing it has infected many humans and captive reptiles. Personal experience is also shared treating infected sliders with topical antimicrobial treatments.
Vancomycin-resistant Staphylococcus aureus (VRSA) is a serious antibiotic-resistant bacterial infection. Overuse and misuse of antibiotics has encouraged the emergence of resistant strains like VRSA. VRSA was first identified in the 1990s and cases have been reported worldwide since then. VRSA poses a major health risk as it can be difficult to treat and has the potential to spread rapidly internationally through human travel and contact. Proper infection control practices and antibiotic stewardship are important to prevent the further emergence and spread of VRSA.
Characterization of Mycobacterium Tuberculosis Complex Strains: A Multicenter...CrimsonpublishersCJMI
Characterization of Mycobacterium Tuberculosis Complex Strains: A Multicenter Retrospective Greek Study by Lamprini Gkaravela in Cohesive Journal of Microbiology & Infectious Disease
Study of the Seroprevalence of Anti-Leptospirosis Antibodies in Subjects in T...IIJSRJournal
Leptospirosis is a tropical and subtropical zoonotic disease culminating as a serious public health problem worldwide, apparently existing as co-infections with various other unrelated diseases, such as malaria. It is caused by spiral bacteria and the main vectors of which are rodents. These bacteria have various survival mechanisms in the environment allowing them to carry out their infectious cycle within their host organisms. The pathophysiological mechanisms pertaining to leptospirosis is still not understood in full and mis or underdiagnosed.
A cross-sectional descriptive study was carried out in three different localities in Niamey where respondents were screened for to demonstrate transmission to humans. Indirect ELISA method as a laboratory diagnostic or screening toll is used by utilizing leptospiral-specific IgG from serum samples of the respondents.
Results from the study showed that 11 people are found to be positive for leptospirosis (with a seroprevalence of 2.75%) with a strong tendency in the slaughterhouse workers which presents a fairly high risk compared to the other localities of the study. Indeed, the different areas/localities of this pilot study do not present the same level of risk because they are not subject to the same risk associated factors. In this vein, we have 87.6% of population exposed to the presence of rats, 48% are in contact with animals, 38.6% live in homes near water and 12.9% go swimming.
This study made it possible, on the one hand, to highlight the transmission of leptospirosis from animals to humans and, on the other hand, to draw attention to the involvement of the various identified risk factors.
This study analyzed 182 pediatric patients under 14 years old with Staphylococcus aureus infections from 3 hospitals in Medellin, Colombia between 2008-2010. 41.4% of patients were under 1 year old. The most common infections were skin and soft tissue infections. Patients with methicillin-resistant S. aureus infections were more likely to have attended daycare centers or taken previous antibiotics. Sixteen different clonal complexes were identified among the isolates, with methicillin-susceptible S. aureus strains showing more diversity. The most common staphylococcal cassette chromosome mec type was IVc, which was linked to Panton-Valentine leukocidin genes. This prevalence of S. aureus infections in
1) The document provides an overview of malaria including epidemiology, etiology, pathogenesis, clinical manifestations, diagnosis, treatment and prevention.
2) Malaria remains a major global health problem, transmitted by the bite of infected Anopheles mosquitoes. Plasmodium falciparum causes the largest disease burden.
3) Clinical presentation varies depending on malaria species, immunity, and transmission intensity. Uncomplicated malaria typically involves fever, while severe malaria can involve organ dysfunction. Diagnosis involves microscopy or rapid tests to detect the parasite. Treatment depends on malaria species and disease severity.
Malaria and Babesiosis co-infectionpptAKWAOWO OROK
This document outlines a proposed seminar series titled "Babesia with Plasmodium Coinfection". The three seminars will cover: 1) The biology of Babesia and Plasmodium parasites, their life cycles, and epidemiology of babesiosis and malaria. 2) Ecological kinetics and immunology of coinfection. 3) Pathophysiology, diagnosis, and treatment of Babesia and Plasmodium infection. The first seminar will focus on the similarities and differences between Babesia and Plasmodium, their life cycles, transmission, geographic distribution, and impact on humans and livestock.
This study aimed to estimate the prevalence of community-onset Clostridium difficile infection (CO-CDI) and identify associated risk factors. The researchers found that 58 cases of CO-CDI were diagnosed among 418,000 people, representing a prevalence of 1.29 per 10,000. Established risk factors like recent antibiotic use were present in 46.3% of cases. However, 16.7% had no known risk factors, suggesting CDI should be considered even without them. Non-established factors like outpatient hospital exposure and travel were also associated with CO-CDI. Larger prospective studies are still needed to further investigate these potential risk factors.
Ebola virus disease - A comprehensive reviewpharmaindexing
This document provides a comprehensive review of Ebola virus disease (EVD). It discusses that EVD is caused by infection with one of five subtypes of the Ebola virus, four of which have caused disease in humans. The virus is believed to originate from fruit bats and then spreads between humans through direct contact with bodily fluids. While there is no approved vaccine or treatment, several are currently being tested. The largest Ebola outbreak on record began in 2014 and spread across Guinea, Liberia, Sierra Leone and Nigeria, resulting in over 1,000 deaths.
RELAPSES AND RECURRENT MALARIA - NEHA PILLAI VINOD, RA1841002010087, DEPARTME...neha1309
This document discusses relapse in malaria. It defines relapse as the return of malaria symptoms after apparent cure of the disease. Relapse is caused by dormant liver stages called hypnozoites in Plasmodium vivax and Plasmodium ovale infections. Several theories are presented to explain the mechanisms of relapse, and the latent tissue stage/hypnozoite theory best accounts for observed relapse patterns. Factors that influence relapse include the number of sporozoites inoculated, acquisition of blood stage immunity, and differences between tropical and temperate regions. The hypnozoite is described as an exoerythrocytic schizont in the liver that causes delayed primary development and relapses.
Gram-negative bacteria commonly cause nosocomial infections like pneumonia and bloodstream infections in debilitated patients. Enterobacteriaceae are the most frequent causes, while non-fermenters like Pseudomonas and Acinetobacter predominate in critically ill patients. Mortality from gram-negative infections remains high, especially with certain multidrug-resistant pathogens. Inappropriate antibiotic therapy, which can include incorrect dosing or use when not indicated, increases morbidity, mortality and resistance. Extended-spectrum beta-lactamases and AmpC beta-lactamases are important resistance mechanisms in key pathogens like K. pneumoniae and Enterobacter species. Carbapenems remain the preferred treatment for infections caused by extended
This document provides a summary of Tibor Farkas's qualifications and experience. He has over 20 years of experience in microbiology and virology research, particularly regarding enteric viruses, at Cincinnati Children's Hospital and previously in Hungary. His research accomplishments include the discovery and characterization of several novel viral pathogens. He has strong skills in laboratory techniques, experimental design, and leadership.
Dr. Kurt Stevenson - Antimicrobial Resistance Surveillance and Management in ...John Blue
Antimicrobial Resistance Surveillance and Management in Hospital and Community Settings - Issues for Human Population Medicine - Dr. Kurt Stevenson, The Ohio State University Medical Center, from the 2012 NIAA One Health Approach to Antimicrobial Resistance and Use Symposium, October 26-27, 2012, Columbus, OH, USA.
More presentations at:
http://www.trufflemedia.com/agmedia/conference/2012-one-health-to-approach-antimicrobial-resistance-and-use
Martin Chang, MBBE final report, 2012_08_21Martin Chang
This document summarizes key information about developing an effective blood-stage malaria vaccine, including:
1) Existing vaccines like RTS,S have shown only partial effectiveness, so more effective vaccines are still needed.
2) The malaria parasite has different life stages, and vaccines target different stages. This report focuses on blood-stage vaccines.
3) Effective immune mechanisms against blood-stage parasites include antibody-dependent cellular inhibition (ADCI) and antibody-dependent respiratory burst (ADRB), but these have not been fully induced by existing vaccines.
Babesiosis, caused by infection with intra erythrocytic parasites of the genus Babesia, is one of the most common infections of free living animals worldwide and is gaining increasing interest as an emerging zoonosis in humans. this is a detailed study on this ......considering all the facts such as definition , management, parthenogenesis, diagnosis, treatment, prevention , etc
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This document is the preface to the book "Salmonella: Methods and Protocols, Second Edition". It summarizes advances in Salmonella research since the first edition, including new methods for detecting and treating Salmonella infections, overcoming antibiotic resistance, vaccine development using nanotechnology, and using genetically modified Salmonella as delivery vectors for cancer therapies. The second edition features new chapters covering molecular detection and identification of Salmonella, quantitative proteomics to identify host factors in Salmonella infection, determining antibiotic resistance, and various microscopy and modeling methods. The preface expresses gratitude to the contributors for sharing their expertise and to the publisher.
Tendances Futures du Web - GTI780 & MTI780 - ETS - A09Claude Coulombe
Présentation sur les tendances futures du Web dans le cadre du cours combiné GTI780 / MTI780, Sujets spéciaux en TI, donné par Claude Coulombe, à l'Ecole de technologie supérieure, Montréal, Automne 2009
1. The study characterized antibody responses to Plasmodium falciparum invasion ligands EBA-140 and EBA-181 in individuals from malaria-endemic areas of Brazil and Cameroon.
2. Responses differed between populations, with African individuals strongly reacting to most EBA fragments while Brazilian individuals from Mato Grosso reacted weakly and those from the Amazon had elevated but lower responses than Africans.
3. When compared to responses against other malaria proteins, the Brazilian population appeared to have more variable ability to recognize P. falciparum invasion ligands, distinct from the African population.
Evolution de la résistance de Plasmodium falciparum aux médicaments antipaludiques. Conférence de la 8ème édition du Cours international « Atelier Paludisme » - CLAIN Jérôme
L'identification du rôle principal du gène pfcrt dans le mécanisme de chloroquino-résistance chez Plasmodium falciparum - Conférence de la 2e édition du Cours international « Atelier Paludisme » - FIDOCK David - Albert Einstein College of Medicine - USA - dfidock@aecom.yu.edu
Risk Based De-identification for Sharing Health DataKhaled El Emam
This presentation describes a methodology, tools, and experiences for the de-identification of health information. The objective is to support data sharing for the purpose of research and public health.
Este documento apresenta um resumo de uma dissertação sobre a resistência do Plasmodium falciparum aos derivados da artemisinina. O documento inclui uma introdução, justificação, objetivos, revisão sistemática de artigos científicos, conclusões e recomendações.
Qu'ils soient dus à un accident de la voie publique, à un accident du travail ou à un geste chirurgical malencontreux, les traumatismes de l'appareil génito-urinaire peuvent laisser derrière eux des séquelles graves perturbant la vie quotidienne, gênant la vie génitale ou menaçant la vie tout court. Ces séquelles ouvrent alors droit à réparation. Pour apprécier l'importance du préjudice, il faudra tenir le plus grand compte des lésions initiales, des gestes qui ont été faits, de l'évolution de ces lésions, spécifique pour chaque organe et enfin du retentissement de ces séquelles sur la vie du sujet. Autant de notions qui font appel à des connaissances médicales étendues auxquelles il faut ajouter des notions de droit relatives à la réparation juridique du dommage corporel que tout chirurgien, expert ou non, se doit de connaître.
This study investigated the relationship between variants of the glycophorin B (GPB) gene and susceptibility to Plasmodium falciparum infection in the Brazilian Amazon. The researchers found that individuals carrying the GYPB*S allele were more likely to be infected with P. falciparum than those without this allele. Additionally, population genetics analysis suggested that natural selection has shaped patterns of genetic diversity at the GYPB locus. This study provides evidence that genetic variation in GPB influences susceptibility to P. falciparum infection in this population.
The Bandiagara Malaria Project has been conducting malaria vaccine research since 1997. They have completed two malaria vaccine trials and published 20 scientific papers. Their research has focused on two candidate vaccines: RTS,S and AMA-1. RTS,S is a recombinant protein combining the circumsporozoite protein with hepatitis B surface antigen and an adjuvant. It has shown modest efficacy in clinical trials. AMA-1 is based on the apical membrane antigen-1 involved in erythrocyte invasion. Antibodies against AMA-1 can block merozoite invasion into red blood cells. The project is a collaboration between the University of Bamako in Mali, the University of Maryland, and
Réponse immunitaire et accès pernicieux - Présentation de la 5e édition du Cours international « Atelier Paludisme » - Edith Christiane BOUGOUMA - Chercheur - Centre National de Recherche sur le Paludisme / CNRFP - Ouagadougou, Burkina Faso - eddycnrfp@yahoo.fr
This study analyzed genetic diversity and population structure of Plasmodium falciparum in 5 populations in the Brazilian Amazon region. Microsatellite markers were analyzed in 196 parasite isolates. There was significant multilocus linkage disequificance within populations, particularly those with fewer mixed infections. However, most isolates had unique multilocus genotypes, indicating genetic diversity. Genetic divergence between populations was substantial but did not correlate simply with geographical distance. The findings suggest distinct population structures and minimal gene flow between foci in the region.
Serum cytokine TNF-alpha and hemoglobin levels in Plasmodium falciparum malar...Apollo Hospitals
This document summarizes a study that assessed the correlation between levels of the cytokine TNF-alpha and hemoglobin in patients infected with Plasmodium falciparum (Pf malaria) compared to healthy controls. The study found significantly higher levels of TNF-alpha and lower hemoglobin levels in Pf malaria patients compared to controls. A strong negative correlation was observed between TNF-alpha and hemoglobin levels in Pf malaria patients, indicating that higher TNF-alpha is associated with more severe anemia. The results suggest TNF-alpha may play an important role in the pathogenesis of anemia caused by Pf malaria.
This study aimed to investigate the presence of arboviruses like dengue virus in clinical samples from 111 malaria patients in the Amazon region of Brazil.
Dengue virus serotype 2 was detected in two patients from Novo Repartimento, Pará who also had active Plasmodium vivax malaria infections. Despite limited data, concurrent dengue and malaria infections are likely more common in the Amazon region than detected, as both diseases co-circulate and have similar transmission vectors and clinical presentations, making dual diagnosis possible. Further research is needed to better understand the frequency of co-infection in this region.
This research article characterized the genetic diversity of Plasmodium vivax and P. falciparum populations from pregnant women in four malaria-endemic countries. Between 2008-2011, nearly 2000 pregnant women were recruited from Brazil, Colombia, India, and Papua New Guinea and followed until delivery, collecting blood samples. Seven P. vivax microsatellite markers were used to genotype 229 P. vivax isolates. P. vivax populations showed moderate to high genetic differentiation between countries and higher diversity than P. falciparum populations from the same areas. Diversity of P. vivax was very high in some settings compared to transmission levels, suggesting stable demographic histories.
This document provides an overview of malaria, including:
- Malaria is caused by Plasmodium parasites transmitted via mosquito bites and causes symptoms like fever and fatigue.
- It is most prevalent in tropical regions of Africa, Asia, and Latin America, infecting hundreds of millions annually and killing thousands.
- The life cycle involves sexual reproduction in mosquitoes and asexual reproduction in humans, starting with the liver and then infecting red blood cells.
- Recurrence of malaria symptoms can occur via recrudescence from incomplete treatment, relapse from dormant liver stages, or reinfection from new mosquito bites.
We present evidence of Plasmodium vivax infection in two homozygous FY*B-33 (Duffy-negative) individuals from the Brazilian Amazon region. Molecular analysis confirmed P. vivax infection through detection of P. vivax small subunit rRNA and circumsporozoite protein genes. One individual had a mixed infection of VK210 and P. vivax-like genotypes, while the other was infected with VK210. Both individuals also had antibodies to the P. vivax merozoite surface protein 1. This provides rare evidence that P. vivax may be capable of invading Duffy-negative red blood cells in some regions, though additional studies are needed to better understand this finding.
Selon une étude, publiée en décembre 2020, la population de la ville de Manaus (Brésil) aurait atteint l’immunité collective. Laurent AVENTIN, PhD – Consultant en santé publique, fait le point pour Le Courrier des Stratèges…
Malaria parasitaemia and socioeconomic status of selected residents of Emohua...IOSRJPBS
The document summarizes a study that investigated the prevalence of malaria and socioeconomic status of residents in Emohua Community, Rivers State, Nigeria. Blood samples were collected from 200 subjects aged 0-17 years old and tested for malaria parasites. The main findings were:
1) The overall malaria prevalence was 53%, with higher rates among females, young children aged 0-6 years, and individuals from lower socioeconomic classes.
2) Subjects not using mosquito nets or using untreated nets had higher infection rates compared to those using treated nets.
3) Most individuals had non-formal education and sought treatment from patent drug sellers rather than hospitals. Treatment-seeking behaviors differed based on education levels.
This document summarizes a case report of tularemia (Francisella tularensis infection) in British Columbia and reviews 16 other cases over 15 years. All cases were acquired rurally and presented most commonly with skin lesions and lymphadenopathy. Two severe cases of sepsis and pulmonary infection were also reported. Physicians and public health workers should be aware of this rare but potentially serious disease endemic to BC, especially for those exposed to wildlife.
Malaria is one of the most common and serious infectious diseases in the world, caused by a parasite transmitted through mosquito bites. It claims more lives each year than any other disease except tuberculosis. Children are especially susceptible and Africa suffers the largest burden, with 90% of global cases and 80% of deaths. The parasites infect liver cells and red blood cells, multiplying rapidly and causing symptoms like fever, chills and anemia when blood cells burst. While transmission typically occurs via mosquito bites, the disease can also be passed from mother to child or through blood transfusions.
This study evaluated the prevalence of malaria parasite among pregnant and non pregnant women attending Federal Medical Centre (FMC) Owerri Imo State Nigeria within the age range of 21-50 years. The molecular identification and speciation of the malaria parasites were carried out using different diagnostic techniques. The blood samples were analyzed using microscopy, Rapid Diagnostic Test (RDT) and Polymerase Chain Reaction (PCR). Results using the microscopy for pregnant women was 181(90.5%) and for non pregnant women, it was 185(92.5%) within the age range of under 21, 41 and above. The result of RDT for pregnant women was 58(32.0%) and for non pregnant women were 46(24.9%). However, the age group of pregnant women that had the highest occurrence of malaria using microscopy was (21-25yrs) with 100% of persons tested positive and (41-45yrs) with 78.8% had the lowest occurrence. For non pregnant women, the age group that had the highest occurrence of malaria parasite was (31-35yrs) with 95.3%of persons reporting tested reporting positive while, (21-25yrs) with 84.6% had the lowest occurrence. Polymerase Chain Reaction (PCR) was used for the speciation of the parasites and the result revealed that Plasmodium falciparum in pregnant women within the ages of 46-50yrs had the highest (96.0%) prevalent followed by Plasmodium vivax for women within the ages of 21-25yrs had the highest (13.6%) occurrence, Plasmodium malariae for women within the ages 21-25yrs and had the highest (9.4%) occurrence. In this study, Polymerase Chain Reaction was very sensitive, takes more large samples at a time and specific for both P. falciparum and non falciparum Plasmodium infections and has many diagnostic advantages over microscopy. Out of 400 venous blood samples collected from both pregnant and non-pregnant women, 27 blood samples had mixed malaria parasite infections. Therefore, following this study, it will be recommended that we urge the pharmaceutical companies to improve on the manufacturing of broad-spectrum antimalarial drugs to cover all species of Plasmodium as it’s done with antimicrobials not only concentrating on the drugs for the treatment of P. falciparum alone.
Genomic epidemiology of Campylobacter jejuni associated with asymptomatic pae...Ben Pascoe
The document summarizes research on Campylobacter jejuni associated with asymptomatic paediatric infection in the Peruvian Amazon. It finds that isolates from Peruvian children have a local gene pool and genotypes rarely seen globally. Lineages associated with asymptomatic infection are proliferating in the region. Though globally circulating strains are present, the regional accessory genome content differs. Poultry is identified as the predominant infection source for children in the Peruvian Amazon. Further sampling is needed to better understand regional differences and reservoirs.
This document discusses strategies to control Porcine Reproductive Respiratory Syndrome (PRRS), a globally significant pig disease. It describes the history and impact of typical and atypical PRRS strains in the Philippines. Diagnostic methods and farm classification systems are outlined. Key control strategies include vaccination, improving biosecurity, and managing pig flow. Proper testing and isolation of replacement stock is important to prevent virus introduction to naive farms.
Transmission heterogeneity has consequences on malaria vaccine researches - Conférence du 5e édition du Cours international « Atelier Paludisme » - Vincent ROBERT - Institut de Recherche pour le Developpement, Paris - v.robert@mnhn.fr
This study found that rat tissues from farms in the Netherlands tested positive for the pla gene, which is a marker for Yersinia pestis. The pla gene sequences from rats were nearly identical to Y. pestis pla but further analysis identified adjacent sequences similar to bacterial replication genes. Attempts to culture or detect other Y. pestis markers from rat tissues were unsuccessful. The findings suggest there are unknown bacteria in rats that contain a pla homolog, which could produce false positive results in Y. pestis detection assays that only target the pla gene. Methods to confirm the presence of Y. pestis should include additional gene targets.
Comparative study of the effectiveness of combination therapies based on atem...Open Access Research Paper
The National Malaria Control Program recommended in 1993, the use of Chloroquina (CQ) as first line drug for malaria treatment, and sulfadoxin pyrimethamin as second drug. After years, Benin knows resistance about these antimalarials. Quinina was to treat gravities. In 2004, the strategy of treatment changed. Treatment of malaria cases is based on use of arteminisinia therapeutic combination. The goal of this study is to be sure that these drugs are efficace before general use in the country and in some regions as Dassa Zounmè where the resistance is up (61. 3% for Chloroquina CQ and 45.9% for SP in 2002).The study is based on: comparison of therapeutic efficacy of artemether Lumefantrine and Artesunate Amodiaquine. Results show that all of the tested drugs have good therapeutic efficacy. Most important rate failure is in Dassa Zounmè (33, 86%) than Parakou (23, 44%). They are parasitologic failure and are probably due to the reinfestation of children. Two drugs have a good parasitological clearance and eliminate fever after 2 days of treatment.
This document summarizes a study that analyzed Duffy blood group genotypes in Plasmodium vivax malaria patients and blood donors in four areas of the Brazilian Amazon region. The study found:
1) A high frequency of the FYA/FYB genotype in both patients and donors, followed by FYB/FYB.
2) Some Duffy genotypes showed significant differences in frequency between patients and donors.
3) Individuals with the FYA/FYB genotype may have higher susceptibility to malaria, while the presence of the FYB-33 allele could provide resistance.
The research aims to design and develop novel bacteriocin peptides as an alternative therapeutic approach to treat malaria by overcoming drug resistance. The objectives are to screen bacteriocin libraries for toxicity and anti-Plasmodium activity, select bacteriocins that inhibit the asexual blood stage of P. falciparum, and optimize bacteriocins' anti-parasite activity by analyzing structures and motifs. This strategy seeks to discover novel bacteriocin domains that can increase antimalarial effectiveness. The research would help provide safe and affordable treatment options to reduce the global malaria burden and economic costs, especially in developing regions facing emerging drug resistance.
This document provides an introduction and literature review on malaria. It discusses the background of malaria, the mosquito and Plasmodium species that cause malaria, and their modes of transmission. Key points include: malaria is caused by Plasmodium parasites transmitted via mosquito bites; the most common species are P. falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi; the parasite has a complex life cycle between mosquitoes and humans; transmission occurs when an infected mosquito bites and injects sporozoites into the bloodstream.
This document describes the development of a PCR-RFLP assay to identify Plasmodium species and variants of P. vivax infecting Anopheles mosquitoes. Specific primers were designed that target regions of the circumsporozoite gene to distinguish P. falciparum, P. malariae, and P. vivax variants VK210, VK247, and P. vivax-like. The assay was tested on artificially infected mosquitoes and showed good agreement with nested PCR. The PCR-RFLP method provides a sensitive way to detect Plasmodium species and variants, which can help understand malaria transmission dynamics.
Malaria is a mosquito-borne infectious disease caused by Plasmodium parasites. It is transmitted via the bites of infected Anopheles mosquitoes and symptoms typically include fever, headache, and in severe cases organ damage or death. While not directly transmissible between humans, infected individuals can pass the parasite to mosquitoes for 1-3 months if left untreated. Prevention strategies focus on vector control like insecticide-treated bed nets and indoor spraying, alongside early diagnosis and prompt treatment with antimalarial drugs.
IOSRPHR(www.iosrphr.org) IOSR Journal of Pharmacyiosrphr_editor
This document summarizes a study that examined the oral microbial pathogens isolated in newly diagnosed HIV positive patients in Dakar, Senegal. 57 newly diagnosed HIV patients were included in the study. The patients' CD4 counts, viral loads, and oral examinations were analyzed. Common oral lesions found were pseudomembranous candidiasis, xerostomia, and gingivitis. Microbial pathogens isolated included Pseudomonas, Klebsiella, Proteus, Staphylococcus aureus, and Escherichia coli. There was an inverse correlation between CD4 count and viral load. The frequency of oral lesions and microbial isolates increased with higher viral loads. Most patients had CD4 counts below
Similar to 2008 co infecções de p. falciparum (20)
This document analyzes the frequency of two polymorphisms (C282Y and H63D) in the HFE gene in malaria patients and blood donors from four states in the Brazilian Amazon region. The study found:
1) No individuals were homozygous for the C282Y polymorphism, and only 5 heterozygous individuals were detected, all from Pará State.
2) The most common genotype for the H63D polymorphism was heterozygous in both patient groups.
3) Allele frequencies for the H63D polymorphism were higher than for the C282Y polymorphism, consistent with other studies on Brazilian populations.
This document summarizes a study that investigated the influence of HLA-DRB1 alleles on the production of antibodies against malaria antigens in individuals naturally infected with Plasmodium vivax in Brazil. The study found an association between HLA-DR3 and HLA-DR5 alleles and lack of antibody response to the amino terminal region of the circumsporozoite protein (CSP). It also found an association between HLA-DR3 and higher antibody response to merozoite surface protein 1 (MSP1). No significant associations were found between HLA-DRB1 alleles and antibody responses to other malaria antigens tested.
1. Researchers studied Plasmodium falciparum field isolates from Colombia, Peru, and Brazil to determine the invasion pathways and ligand polymorphisms used.
2. They found that most isolates from Colombia and Peru invade red blood cells through an atypical pathway that is resistant to all enzyme treatments, unlike known pathways.
3. This unusual pathway was associated with specific variants of PfRh2a, PfRh5, and EBA-181 ligands, suggesting these proteins play a major role in this pathway. The study demonstrates diversity in invasion mechanisms between regions.
This study examined 51 Brazilian Plasmodium falciparum isolates for polymorphisms in the Pfmdr1 gene thought to be associated with chloroquine resistance. 49 of the isolates were found to be resistant to chloroquine in vitro, while all were sensitive to mefloquine, amodiaquine, and quinine. The isolates were analyzed for three Pfmdr1 polymorphisms: Asn86Tyr, Asn1042Asp, and Asp1246Tyr. Asn86Tyr was not detected in any isolates, while Asn1042Asp was found in 50 isolates and Asp1246Tyr was found in all 51 isolates. This provides support that As
This study evaluated the distribution of Plasmodium vivax variants (VK210, VK247, and P. vivax-like) in three areas of Brazil using a new GFM-PCR-ELISA technique. All variants were found in all three areas. VK210 was most commonly found as a single infection while the others occurred in mixed infections. VK210 was associated with the highest parasitemia levels while P. vivax-like had the lowest. Parasitemia clearance times did not differ based on variant or treatment schedule. The new technique was accurate for epidemiological surveys of the vivax complex.
This document analyzes genetic variation at the Pfs48/45 gene and microsatellite loci in 255 Plasmodium falciparum isolates from 5 populations. It finds:
1) Alleles and haplotypes of 5 SNPs in the Pfs48/45 gene varied extremely between populations, much more so than alleles at 11 neutral microsatellite loci.
2) Measurements of between-population allele frequency variation (FST) were 4-7 times higher for Pfs48/45 than microsatellites, both within and between continents.
3) The highly skewed Pfs48/45 patterns suggest divergent selection on the protein's amino acid sequence between populations, indicating it may determine game
This study evaluated four recombinant proteins representing the 19 kDa C-terminal region of the Plasmodium vivax merozoite surface protein-1 (MSP119) for detecting P. vivax antibodies in human serum samples. The sensitivity of an ELISA using the recombinant proteins to detect antibodies in 200 samples from individuals with P. vivax infection ranged from 90-93.5%. Specificity using control samples without P. vivax exposure was 98.3-100%. The study demonstrates the potential of an ELISA using recombinant MSP119 proteins for serological detection of P. vivax infection.
This study compared ELISA and PCR-ELISA techniques for detecting human Plasmodium parasites in Anopheles mosquitoes from the Amazon region of Brazil. The PCR-ELISA technique confirmed all positive and negative ELISA results but detected additional Plasmodium species in 5 of the 32 positive mosquitoes that were not detected by ELISA alone. The PCR-ELISA is more sensitive than ELISA for detecting human malaria parasites in mosquitoes.
1) O documento analisa os casos de malária no estado de Santa Catarina entre 1996-2001, com 5,5% das 4.707 amostras sendo positivas.
2) Plasmodium vivax causou 69% dos casos, Plasmodium falciparum 25,6%, infecções mistas 5% e Plasmodium malariae 0,4%.
3) 67,4% dos casos foram importados e 32,6% autóctones, com aumento de casos importados nos anos subsequentes.
1) The study evaluated the performance of the OptiMal malaria rapid diagnostic test under different storage conditions of 25°C, 30°C, and 39°C for 24, 48, and 72 hours.
2) The test detected all 111 positive blood samples except for 2 low parasitemia Plasmodium malariae samples.
3) The study suggests that the OptiMal test can be used for malaria diagnosis in Brazilian regions, though further research is needed to evaluate its performance under different environmental conditions like humidity.
This study investigated genetic mutations associated with chloroquine resistance in Plasmodium falciparum samples from the Brazilian Amazon region. The study analyzed 40 samples from 4 localities for mutations in the pfmdr1, cg2, and pfcrt genes. It found 100% of samples contained mutations in pfmdr1 codons 184, 1042, and the cg2 gamma region associated with chloroquine resistance. Most samples also contained the pfcrt K76T mutation, except some from Porto Velho which matched a Thai resistant genotype. This research contributes to understanding the molecular basis of widespread chloroquine resistance in this region.
1. The study developed a new PCR/RFLP technique to identify the 3 genotypes of Plasmodium vivax circumsporozoite protein (VK210, VK247, and P. vivax-like) using DNA extracted from blood samples.
2. The technique uses PCR amplification of the central immunodominant region of the CSP gene followed by restriction enzyme digestion and fragment analysis to distinguish the genotypes.
3. Testing demonstrated the technique could accurately identify the genotypes using plasmid controls for each variant, and that it had high sensitivity detecting parasitemia levels as low as 0.0069 parasites per microliter.
This study investigated the frequencies of ABO blood group genotypes and alleles in Plasmodium falciparum malaria patients and blood donors from the Brazilian Amazon region. The researchers found that over half of individuals had the ABO*O01O01 genotype. The ABO*AO01 genotype was the second most common. No significant differences were detected in genotype or allele frequencies between the malaria patients and blood donors. Analysis of O alleles found the O1 variant allele to be most frequent in both groups, with no evidence of the homozygous O2 allele.
1. A study analyzed genetic and immune response differences between P. vivax circumsporozoite (CS) genotypes VK210 and P. vivax-like.
2. Phylogenetic analysis of 18S rRNA and CytB genes found high similarity between the genotypes, with zero nucleotide diversity, placing them in the same clade.
3. Individuals infected with P. vivax-like had a lower antibody response against CS repetitive region peptides than those with VK210, suggesting variation is limited to the CS repetitive region.
This study evaluated antibody responses to the Pv200L fragment of Plasmodium vivax merozoite surface protein-1 (PvMSP-1) in individuals from 4 malaria-endemic regions in Brazil. Plasma samples from 261 P. vivax infected individuals were tested for antibodies to Pv200L by ELISA. The frequency of antibody responders ranged from 71.9-98.7% between regions and correlated with malaria transmission intensity. Higher antibody levels were also associated with greater past exposure to malaria parasites. Results provide evidence that Pv200L elicits naturally acquired antibodies and could be a potential vaccine candidate.
This document summarizes a study that investigated the influence of HLA-DRB1 alleles on the production of antibodies against malaria antigens in individuals naturally infected with Plasmodium vivax in Brazil. The study found an association between HLA-DR3 and HLA-DR5 alleles and lack of antibody response to the amino terminal region of the circumsporozoite protein (CSP). It also found an association between HLA-DR3 and higher antibody response to merozoite surface protein 1 (MSP1). No significant associations were found between HLA-DRB1 alleles and antibody responses to other malaria antigens tested.
1) Field isolates of Plasmodium falciparum from Colombia and Peru were found to invade red blood cells through an atypical pathway that was resistant to all enzyme treatments, unlike what is typically seen.
2) The invasion pathways and ligand polymorphisms differed between Colombian, Peruvian, and Brazilian isolates, with Peruvian isolates showing a combination of Colombian and Brazilian characteristics.
3) The atypical resistant pathway was associated with specific variants of PfRh2a, PfRh5 and EBA-181, which may be major players in this pathway based on expression levels.
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2. A. Lorenzetti et al. / Acta Tropica 107 (2008) 8–12 9
individuals concurrently infected by both species have experienced symptoms were defined as “present” or “absent” by the medical
significant reductions in fever. Recently, it was reported in Thailand staff accordingly to the temperature measurements performed by
that patients with dual P. vivax–P. falciparum infections have higher the nurses and also by a detailed, specific interview, regarding
fevers than those with single-species infections (McKenzie et al., unusual and/or previously experienced clinical malaria manifes-
2006). tation.
Previous studies have pointed to highly relevant limitations of
traditional microscopy-based detection techniques (Snounou et al., 2.3. Laboratory analysis
1993; Postigo et al., 1998). Indeed, the deficiency to detect mixed
infections by the thin and thick blood film methods make treatment Thick blood films (TBFs) were confirmed by independent expe-
difficult as it is species-specific. Polymerase chain reaction (PCR) rienced microscopists who were unaware of each result according
has been shown to be efficient in the diagnosis of the four human to the World Health Organization recommended procedures. Blood
malaria parasites and, therefore, also on identifying high prevalence samples were stored at −20 ◦ C until laboratory analyses. Samples
of mixed infections (Roper et al., 1996; May et al., 1999). The aim were treated with Proteinase K, and nucleic acids were extracted by
of this study was to assess the prevalence pattern of mixed-P. fal- using two rounds of phenol:chloroform:isoamyl alcohol (25:24:1),
ciparum malaria infections in Brazil by molecular diagnosis and to one round of chloroform and one of ether, followed by ethanol pre-
address its clinically important features. cipitation. The extracted nucleic acid samples were dissolved in
sterile pure deionised water, and stored at −20 ◦ C prior to use. The
2. Materials and methods semi-nested PCR was based on the protocol accordingly to Kimura
et al. (1997). The target was the SSU rDNA gene, and species-specific
2.1. Study population primers were used in the assay. Briefly, the first PCR rDNA ampli-
fication was performed with Plasmodium genus-specific primers.
Sample collection took place from May 2003 to August 2005. Positive samples served as template for the nested reaction. The
One hundred and fifteen male and female malaria patients nested PCR amplifications were performed using P. falciparum, P.
´
from four regions of the Brazilian Amazon: Macapa, state of vivax, and P. malariae SSU rDNA primers plus universal primer from
Amapa (00◦ 02 20 S; 51◦ 03 59 W); Novo Repartimento, state of
´ the first reaction. The fragments obtained were seen at about 110-
Para (04◦ 19 50 S; 49◦ 47 47 W), Porto Velho, state of Rondˆ nia
´ o bp. As a positive control we used blood samples with P. falciparum,
(−08◦ 45 43 S; 63◦ 54 14 W); and Placido de Castro, state of Acre
´ P. vivax, and P. malariae TBF plus molecular results to Plasmodium.
(10◦ 16 33 S; 67◦ 09 00 W) were enrolled in this study. These indi- As a negative control we used blood samples from blood donors
viduals presented on their own initiative, and were invited to living in the same areas with negative microscopy and molecular
participate in this study at the public healthcare clinics in each results to Plasmodium. The products were visualized in 2% agarose
study area. They were all over the age of 18 and had positive gel stained with ethidium bromide.
thick blood film (TBF) results for P. falciparum single infection. We
excluded from the study pregnant women, patients under the age of 2.4. Data analysis
18 years and no other concomitant illness. Participants were asked
to sign a written consent form before blood samples were drawn. Epi Info version 6.04b (CDC, Atlanta, US) was used for data stor-
The consent form was co-signed by a staff member of the clinic. age and statistical analyses. Proportions and categorical data were
Clinical and epidemiological data such as age, gender, past history compared by the Chi-square test, with Yate’s correction, in cases
of malaria, and current infection information were obtained from a of 2 × 2 contingency tables, or Fisher exact test (two-tailed). The
specific interview conducted by the physicians and also from med- adopted significance level for statistical inference was p < 0.05.
ical records. The protocol for this study was reviewed and approved
a ´
by the Research Board of the Faculty of Medicine from S˜ o Jose do 3. Results
Rio Preto.
The parasitaemia on the thick blood films ranged from 25 to
2.2. Clinical evaluation 6500 parasites/mm3 . P. falciparum parasitaemia was lower among
patients with mixed infections than among patients with single-
All patients voluntarily sought medical assistance presenting species infections, but this difference was insignificant (Chi-square
with uncomplicated clinical malaria symptoms as evaluated by ´
5403, p > 0.7137). In Macapa patients, the previous malaria experi-
the physicians and/or nurses enrolled in the malaria diagnosis and ence (in number of episodes) was 1.5 (±2.01); in those from Porto
treatment routine of the Brazilian government national program. Velho was 0.9 (±1.57); in those from Novo Repartimento was 1.7
Individuals who presented at least one of the following symptoms: ´
(±2.62) and from Placido de Castro was 1.6 (±2.57). As for their
fever, headache, and shiver, in addition to microscopic positivity, ages, the geometric means in each area were 28 (±1.35), 25 (±2.35),
were included in the post-diagnostic medical evaluation. Likewise, 32 (±1.15), and 30 (±1.02) years old, respectively, ranging from 18
Table 1
Identification of Plasmodium falciparum mixed-infections as determined by malaria genotypic test among 115 patients from four Brazilian Amazon areas
Molecular diagnosis
P. falciparum P. falciparum + P. malariae P. falciparum + P. vivax P. falciparum + P. malariae + P. vivax
Novo Repartimento/PA (n = 16) 14 (16.67%) – 2 (7.14%) –
´
Macapa/AP (n = 37) 26 (30.95%) 1 (50%) 10 (35.71%) –
Porto Velho/RO (n = 50) 35 (41.67%) – 14 (50%) 1 (100%)
´
Placido de Castro/AC (n = 12) 9 (10.71%) 1 (50%) 2 (7.14%) –
Total 84 2 28 1
´ ´
PA: Para; AP: Amapa; RO: Rondˆ nia; AC: Acre.
o
3. 10 A. Lorenzetti et al. / Acta Tropica 107 (2008) 8–12
Table 2 New Guinea (Mehlotra et al., 2000), and almost equally often in the
Frequency (%) of clinical aspects (fever, headache and shiver) as function of P. falci-
subjects from Guinea Bissau (Snounou et al., 1993), Laos (Toma et
parum malaria attacks from Brazilian Amazon region, May 2003 to August 2005
al., 2001), and Mozambique (Marques et al., 2005). Several reports
Clinical aspects P. falciparum infections demonstrate that P. falciparum infections may be influenced by the
Single (n = 84) Mixed (n = 31) p presence of a congener (Mason et al., 1999) and frequently sup-
Fever 84 (100%) 28 (90.32%) 0.0182
press P. vivax in cases of co-inoculation (Boyd and Kitchen, 1937;
Headache 75 (89.29%) 23 (75.19%) 0.0461 Garham et al., 1956; Looareesuwan et al., 1987). These data con-
Shiver 78 (92.86%) 24 (77.42%) 0.0405 firm that P. falciparum co-infections frequently occur in Brazilian
p values are based on Fisher exact test. malaria endemic areas and the pair P. falciparum–P. vivax seems to
be the commonest. This information needs further evaluation, in
order to measure infection and densities of asexual/sexual forms
to 52 years in all studied areas. As summarized in Table 1, 73.04% dynamics.
of P. falciparum single infections and 26.95% of mixed infections When mixed-infection is misdiagnosed as a P. vivax single-
were found. Amongst mixed infections, the majority was double species infection, treatment can lead to a surge in P. falciparum
infection (96.77%). parasitaemia (Mason and McKenzie, 1999). Many factors confound
Of all the clinical aspects recorded during the 115 P. falciparum the relationship between parasitaemia and disease, but there is
malaria attacks, a typical febrile paroxysm was the most frequent generally a loose positive correlation between circulating para-
clinical symptom, observed in 97.39% of cases, as a single or an site load and clinical status. Conversely, previous reports suggest
associated manifestation. The combination among the three clini- that P. vivax–P. falciparum interactions in mixed infections may
cal aspects assessed (fever, headache and shiver) showed fever plus have profound clinical effects in uncomplicated malaria, perhaps
headache in 85.21% of cases, while fever plus shiver was reported by maintaining P. falciparum densities below the fever threshold
in 88.69%. There was a lower frequency of individuals presenting (Field, 1949; White, 1997). An explanation for the reduction of the
clinical manifestations in the P. falciparum mixed-infections group symptom in mixed infection carriers could be the mean age of the
compared to the P. falciparum single infections one (Fisher exact affected patients and time of residence in the endemic area, since
test, p < 0.05; Table 2). Clinical aspects were not correlated with it is well documented by different authors that immunity can play
total parasitaemia (Chi-square 0.930, p > 0.99). There is no correla- an important role in malaria symptom relief (Alves et al., 2002;
tion between the individuals’ age or past history of malaria and the Coura et al., 2006). Other possibility could be related to the num-
reduction of their symptom in all study areas. ber of previous malaria episodes (Coura et al., 2006), but in the
present investigation we were not able to find a positive correlation
4. Discussion in all the raised points. In our study, the mean number of previous
malaria episodes was low and the majority of the patients are living
Although P. vivax is the most common human malaria parasite under 5 years in the endemic areas. In fact, in the Brazilian Amazon
in Brazil, P. falciparum accounts for approximately 30% of overall region P. vivax and P. falciparum malaria predominate in Mesoen-
cases, and is a greater cause of morbidity and mortality. The dis- demic conditions with wide variations in transmission, as it can be
tribution of P. falciparum infection is focal, more common than P. observed by the non-immune or semi-immune status of the adult
vivax in some areas, but very rare or absent in others (Camargo population as well as by the asymptomatic carriers (Alves et al.,
et al., 1999). Genetic divergence between Brazilian P. falciparum 2002; Coura et al., 2006). Consequently, minor clinical malaria evi-
populations is very substantial with distinct population structures dence was referred by the studied patients once a reduction in the
and minimal gene flow and these aspects may affect the rate of severity of malaria symptoms was reported in individuals with lim-
increasing drug resistance. This is consistent with the view that P. ited pre-exposure to different species (Gunewardena et al., 1994).
falciparum malaria in the largest endemic region of the Americas Another possible reason for the lack of association with age and past
should not be seen as a single entity, and different strategies for history of malaria relies on McKenzie et al. (2006) findings, suggest-
prevention and control may be designed for its diverse endemic ing that parasitaemia is not the most important symptom trigger.
locations (Machado et al., 2004). On the other hand, in mixed- They indicate that one species prevalence over the other can be
phenotype (drug resistant and sensitive) P. falciparum infection, important since individuals with P. vivax higher parasitaemia over
ineffective treatment can lead to higher densities of the resistant P. falciparum show fever reduction compared to those with higher
protozoan (Mason and McKenzie, 1999). It may be necessary to P. falciparum number of parasites. Concurrently, infecting malaria
assess the prevalence of genotypes and/or mixed-species infections species are equally suppressive with P. falciparum dominating P.
before control measures are implemented (Marques et al., 2005). vivax, but P. vivax attenuating the clinical complications of P. falci-
Mixed infections diagnosed by microscopy in patients admit- parum (Mayxay et al., 2004). This last affirmative can explain the
ted in healthcare malaria clinics and in epidemiological surveys clinical observations occurring in our studied patients. On the other
are a small proportion of the total prevalence (McKenzie and hand, it is not a general consensus that higher fevers, per se, are
Bossert, 1999), but almost all combinations of species have been consequences of greater clinical severity or more effective immune
found within human populations and individuals (Mckenzie et al., responses (McKenzie et al., 2006).
2002). Interestingly, Bruce et al. (2000) explore species interac- In spite of the fact that we do not have data on exact oral temper-
tions through the interplay between density dependent regulation ature measurements and the subjective character of patient’s report
and differential growth and clearance rates of individual parasite on headache and shiver, a limitation we acknowledge, we observed
populations. Growth of one parasite population to above threshold that P. falciparum mixed infections are associated with reduc-
density would trigger density-dependent regulation thus inhibiting tion in the prevalence of these three symptoms in this sampling
minority co-infections. P. falciparum mixed-infections, in this study, of the Brazilian Amazon region. Nevertheless, symptom reduc-
were identified in 26.95% of all samples studied. In previous molec- tion was not correlated with total parasitaemia. Finally, since the
ular studies from Brazil, P. falciparum mixed-species were detected virulence has been shown to be associated with selectivity of
in 23.96% (Cavasini et al., 2000), 20% (Alves et al., 2002), and 17.62% erythrocyte invasion (Chotivanich et al., 2000), an overall under-
(Scopel et al., 2004). All these frequencies were lower than those standing of the biological interactions of the parasite/host is such
reported in studies from Thailand (Zhou et al., 1998) and Papua that one could be imperative in clinical implications (McKenzie et
4. A. Lorenzetti et al. / Acta Tropica 107 (2008) 8–12 11
al., 2006). For instance, we could observe dramatic differences in ´
Jose do Rio Preto. Financial support: FAPESP (02/09546-1) and CNPq
P. falciparum Brazilian population’s structure compared to Thailand (302353/03-8).
(Anderson et al., 2000), since heterozygosity in Brazilian parasites
is lower (Machado et al., 2004). Furthermore, innate resistance
References
to malaria infections in humans was attributed to blood group
antigen variations. Invasion of red blood cells (RBC) occurs when Alves, F.P., Durlacher, R.R., Menezes, M.J., Krieger, H., Silva, L.H.P., Camargo, E.P., 2002.
the extracellular form of the parasite, the merozoites, attaches to High prevalence of asymptomatic Plasmodium vivax and Plasmodium falciparum
the surface of an uninfected RBC. We observed significant cor- infections in native Amazonian populations. Am. J. Trop. Med. Hyg. 66, 641–648.
Anderson, T.J.C., Haubold, B., Williams, J.T., Estrada-Franco, J.G., Richardson, L.,
relation regarding MNSs (P. falciparum erythrocyte receptor) and
Mollinedo, R., Bockarie, M., Mokili, J., Mharakurwa, S., French, N., Whitworth, J.,
Duffy blood (acts as a RBC receptor for P. vivax) group pheno- Velez, I.D., Brockman, A., Nosten, F., Ferreira, M.U., Day, K.P., 2000. Microsatellites
types between blood donors and malaria patients in the same reveal a spectrum of population structures in the malaria parasite Plasmodium
falciparum. Mol. Biol. Evol. 17, 1467–1482.
studied areas (Cavasini et al., 2006). The results of the current
Black, J., Hommel, M., Snounou, G., Pinder, M., 1994. Mixed infections with Plasmod-
work suggest that P. falciparum mixed-infections can affect Brazil- ium vivax and Plasmodium malariae and fever in malaria. Lancet 343, 1095.
ian transmission patterns by attenuation of P. falciparum disease Boyd, M.F., Kitchen, S.F., 1937. Simultaneous inoculation with Plasmodium vivax and
(Black et al., 1994) and ultimately may have an effect in the way this Plasmodium falciparum. Am. J. Trop. Med. Hyg. 17, 855–861.
Bruce-Chwatt, L.J., 1963. A longitudinal survey of natural infection in a group of West
species establishes itself in the population. Further studies based African adults. Part I. West African Med. J. 12, 141–143.
on accurate oral fever measurement accompanied by other symp- Bruce, M.C., Donnelly, C.A., Alpers, M.P., Galinski, M.R., Barnwell, J.W., Walliker, D.,
toms evaluation, in different human populations and localities, will Day, K.P., 2000. Cross-species interactions between malaria parasites in humans.
Science 287, 845–848.
clarify the importance of Plasmodium mixed infections in malaria Camargo, L.M.A., Noronha, E., Salcedo, V.J., Dutra, A.P., Kriger, H., Pereira da Silva, L.H.,
clinical outcome. Camargo, E.P., 1999. The epidemiology of malaria in Rondˆ nia (Western Amazon
o
The apparent frequency of mixed infections is dependent on region, Brazil): study of a riverine population. Acta Trop. 72, 1–11.
Cavasini, C.E., Mattos, L.C., Alves, R.T., Couto, A.A., Calvosa, V.S., Domingos, C.R.,
the technique used for parasite analyses. An inadequate P. falci- Castilho, L., Rossit, A.R., Machado, R.L., 2006. Frequencies of ABO, MNSs, and
parum diagnosis within a mixed infection could result in incorrect Duffy phenotypes among blood donors and malaria patients from four Brazilian
treatment and consequently, in a severer disease (Mayxay et al., Amazon areas. Hum. Biol. 78, 215–219.
Cavasini, M.T.V., Ribeiro, W.L., Kawamoto, F., Ferreira, U.M., 2000. How prevalent is
2004). Double-species infections can commonly be detected by
Plasmodium malariae in Rondˆ nia, Western Brazilian Amazon? Rev. Soc. Bras.
o
both microscopy and PCR methods; whereas most triple-species Med. Trop. 33, 489–492.
infections are frequently detected only by molecular techniques Chotivanich, K., Udomsangpetch, R., Simpson, J.A., Newton, P., Pukrittayakamee, S.,
Looareeswan, S., White, N.J., 2000. Parasite multiplication potential and the
(May et al., 2000). Our results confirm that Plasmodium mixed infec-
severity of falciparum malaria. J. Infect. Dis. 181, 1206–1209.
tions diagnosis is underestimated in the four studied areas. Some Cohen, J.E., 1973. Heterologus immunity in human malaria. Quart. Rev. Biol. 48,
limitations of thick blood film could result in misdiagnose, such 467–489.
as the difficulty in distinguishing the young-form parasites of the Coura, J.R., Suarez-Mutis, M., Ladeia-Andrade, S., 2006. A new challenge for malaria
control in Brazil: asymptomatic Plasmodium infection—a review. Mem. Inst.
human malaria species, the undetectable presence of P. vivax liver Oswaldo Cruz 101, 229–237.
hypnozoites and the fact that many infections are at densities below Field, J.W., 1949. Blood examination and prognosis in acute falciparum malaria.
the threshold detectable by microscopy (Black et al., 1994). Further- Trans. R. Soc. Trop. Med. Hyg. 43, 33–48.
Garham, P.C.C., Laison, R., Gundars, A.E., 1956. Some observations on malaria para-
more, microscopists, on finding one species, might not search the sites in a chimpanzee, with particular reference to the persistence of Plasmodium
slide for a rare second species (Zhou et al., 1998). In spite of the reichenowi and P. vivax. Ann. Soc. Med. Trop. Belge 36, 813–821.
recommendation by World Health Organization and the Ministry Gunewardena, D.M., Carter, R., Mendis, K.N., 1994. Patterns of acquired anti-malarial
immunity in Sri Lanka. Mem. Inst. Oswaldo Cruz 89, 63–65.
of Health in Brazil regarding the TBF control after treatment of the Hill, R.B., Cambournac, F.J.C., Sim˜ es, M.P., 1943. Observations on the course of
o
initial malaria attack, performed 3–4 weeks following initial diag- malaria in children in an endemic region. Am. J. Trop. Med. Hyg. 23, 147–
nosis, one can still figure the problem of up to a month of a second 162.
Kimura, M., Kneko, O., Liu, Q., Zhou, M., Kawamoto, F., Wataya, Y., Otani, S., Yam-
Plasmodium non-eliminated species carrier within the local popula-
aguchi, Y., Tanake, K., 1997. Identification of the four species of human malaria
tion. Even so, considering the Brazilian health system conditions, it parasites by nested PCR that targets variant sequences in the small subunit rRNA
is impossible to include species-specific PCR as a routine in malaria gene. Parasitol. Intern. 46, 91–95.
Looareesuwan, S., White, N.J., Chittamas, S., Bunnag, D., Harinasuta, T., 1987. High
diagnosis. Therefore, we propose that a plausible action would be
rate of Plasmodium vivax relapse following treatment of falciparum malaria in
to improve TBF conditions in the field by simple proceedings like Thailand. Lancet 2, 1052–1055.
equipment maintenance and technician’s supervision and support. Luxemberger, C., Ricci, F., Nosten, F., Raimond, D., Bathet, S., White, N.J., 1997. The
In conclusion, our results point to the need of improving epidemiology of severe malaria in an area of low transmission in Thailand. Trans.
R. Soc. Trop. Med. Hyg. 91, 256–262.
microscopy or changing for another accurate diagnosis method, ´
Machado, R.L.D., Povoa, M.M., Calvosa, V.S.P., Ferreira, M.U., Rossit, A.R.B., Santos,
especially in endemic areas, to differentiate among human malaria E.J.M., Conway, D.C., 2004. Genetic structure of Plasmodium falciparum popula-
species. If some interactions between species are such that one tions in the Brazilian Amazon region. J. Infect. Dis. 190, 1547–1555.
´ ´
Marques, P.X., Saute, F., Pinto, V.V., Cardoso, S., Pinto, J., Alonso, P.L., Rosario, V.E.,
may affect by even minor differences the clinical manifestation of Arez, A.P., 2005. Plasmodium species mixed infections in two areas of Manhica ¸
another, more investigations are necessary in order to clarify the District, Mozambique. Int. J. Biol. Sci. 1, 96–102.
role of mixed-infections in P. falciparum disease severity and also Mason, D.P., McKenzie, F.E., 1999. Blood-stage dynamics and clinical implications
of mixed Plasmodium vivax–Plasmodium falciparum infections. Am. J. Trop. Med.
in this parasite transmission dynamics. Hyg. 61, 367–374.
Mason, D.P., McKenzie, F.E., Bossert, W.H., 1999. The blood-stage dynamics of
mixed Plasmodium malariae–Plasmodium falciparum infections. J. Theor. Biol.
198, 549–566.
Acknowledgements
May, J., Falusi, A.G., Mockenhaupt, F.P., Ademowo, O.G., Olumese, P.E., Bienzle, U.,
Meyer, C.G., 2000. Impact of subpatent multi-species and multi-clonal plas-
To the population enrolled in this study. To Aline Barroso, Maria modial infections on anaemia in children from Nigeria. Trans. R. Soc. Trop. Med.
Hyg. 94, 399–403.
Cristina Figueredo and Mauro Tada for help in field work. To Pro-
May, J., Mokenhaupt, F.P., Ademowo, O.G., Olumese, P.E., Bienzle, U., Meyer, C.G., 1999.
fessor Luiz Hildebrando Pereira da Silva for facilities at Cepem. High rate of mixed and subpatent malarial infections in southwest Nigeria. J.
´
To Dr. Marinete Marins Povoa and Alexandre Moura for the com- Infect. Dis. 61, 339–343.
ments and suggestions. P.A.F. is research studentship from Fapesp Mayxay, M., Khanthavong, M., Lindegardh, N., Keola, S., Barends, M., Pongvongsa, T.,
Yapom, R., Annerberg, A., Phompida, S., Phetsouvanh, R., White, N.J., Newton, P.N.,
and A.L., A.C.B.D. and R.S.R.P. from CNPq. A.R.B.R. and R.L.D.M. are 2004. Randomized comparison of chloroquine plus sulfadoxine-pyrimethamine
¸˜
research fellowship from Fundacao Faculdade de Medicina de S˜ o a versus artesunate plus mefloquine versus artemether-lumefantrine in the treat-
5. 12 A. Lorenzetti et al. / Acta Tropica 107 (2008) 8–12
ment of uncomplicated falciparum malaria in the Lao People’s Democratic Richie, T.L., 1988. Interactions between malaria parasites infecting the same verte-
Republic. Clin. Infect. Dis. 39, 1139–1147. brate host. Parasitology 96, 607–609.
McKenzie, F.E., Bossert, W.H., 1997. Mixed-species Plasmodium infections of humans. Roper, C., Elhassan, I.M., Hviid, L., Giha, H., Richardson, W., Babiker, H., Satti, G.M.,
J. Parasitol. 83, 593–600. Theander, T.G., Arnot, D.E., 1996. Detection of very low level Plasmodium falci-
McKenzie, F.E., Bossert, W.H., 1999. Multi-species Plasmodium infections of humans. parum infections using the nested polymerase chain reaction and a reassessment
J. Parasitol. 85, 12–18. of the epidemiology of unstable malaria in Sudan. Am. J. Trop. Med. Hyg. 54,
Mckenzie, E.F., Jeffery, M.G., Collins, W.E., 2002. Plasmodium malariae infection 325–331.
boots Plasmodium falciparum gametocyte productions. Am. J. Trop. Med. Hyg. Scopel, K.K.G., Fontes, C.J., Nunes, A.C., Horta, M.F.M., Braga, E.M., 2004. High preva-
67, 411–414. lence of Plasmodium malariae infections in a Brazilian Amazon Endemic area
McKenzie, F.E., Smith, D.L., O’Meara, W.P., Forney, J.R., Magil, A.J., Permpanich, B., (Apiacas–Mato Grosso State) as detected by polymerase chain reaction. Acta
Erhart, L.M., Sirichaisinthop, J., Wongsrichanalai, C., Gasser Jr., R.A., 2006. Fever Trop. 90, 61–64.
in patients with mixed-species malaria. Clin. Infect. Dis. 42, 1713–1718. Snounou, G., Virriaykosol, S., Jarra, W., Thaithong, S., Brown, K.N., 1993. Identification
Mehlotra, R., Lorry, K., Kastens, W., Miller, S.M., Alpers, M.P., Bockarie, M., Kazura, J.W., of the four human malaria parasite species in field samples by the polymerase
Zimmerman, P.A., 2000. Random distribution of mixed-species malaria infection chain reaction and detection of a high prevalence of mixed infections. Mol.
in Papua New Guinea. Am. J. Trop. Med. Hyg. 62, 225–231. Biochem. Parasitol. 58, 283–289.
´ ´ ´
Ministerio da Saude, 2003. Secretaria de Vigilˆ ncia em Saude. Programa Nacional de
a Toma, H., Kobayashi, J., Vannachone, B., Arakawa, T., Sato, Y., Nambanya, S.,
¸˜ ´
Prevencao e Controle de Malaria. PNCM. Bras´lia, DF.
ı Manivong, K., Inthakone, S.A., 2001. Study on malaria prevalence in southeast-
Molineaux, L., Storey, J., Cohen, J.E., Thomas, A., 1980. A longitudinal study of human ern Laos by the polymerase chain reaction assay. Am. J. Trop. Med. Hyg. 64,
malaria in the West African Savanna in the absence of control measures: rela- 257–261.
tionships between different Plasmodium species, in particular P. falciparum and White, N.J., 1997. Assessment of the pharmacodynamic properties of antimalarial
P. malariae. Am. J. Trop. Med. Hyg. 29, 725–737. drugs in vivo. Antimicrob. Agents Chemother. 41, 1413–1422.
Postigo, M., Mendoza-Leon, A., Perez, H.A., 1998. Malaria diagnosis by the poly- Zhou, M., Liu, Q., Wongsrichanalai, C., Suwonkerd, W., Panart, K., Matsuoka, H., Fer-
merase chain reaction: a field study in southeastern Venezuela. Trans. R. Soc. reira, U.M., 1998. High prevalence of Plasmodium malariae and Plasmodium ovale
Trop. Med. Hyg. 92, 509–511. in malaria patients along the Thai-Myanmar border, as revealed by acridine
´
Povoa, M.M., Silva, A.M.M., Santos, C.C., Segura, M.N.O., Machado, R.L.D., 2000. orange staining diagnosis. Trop. Med. Int. Health 3, 304–312.
´
Malaria transmission. Rev. Cien. Saude 52, 208–212.