This document provides information on arboviruses and dengue fever. It discusses:
1) Arboviruses belong to three virus families including Togaviruses, Bunyaviruses, and Flaviviruses. Dengue fever is caused by any one of four related flaviviruses.
2) Dengue is the biggest arbovirus problem worldwide, transmitted by Aedes mosquitoes. It causes dengue fever and the potentially lethal dengue hemorrhagic fever/dengue shock syndrome.
3) Diagnosis involves serology to detect IgM and IgG antibodies or isolation of the virus. There is no vaccine or antiviral treatment, so management focuses on supportive care and
A picornavirus is a virus belonging to the family Picornaviridae, a family of viruses in the order Picornavirales. Vertebrates, including humans, serve as natural hosts. Picornaviruses are nonenveloped viruses that represent a large family of small, cytoplasmic, plus-strand RNA viruses with a 30-nm icosahedral capsid.
Polio: flaccid paralysis, major and minor
disease, fecal-oral
Coxsackievirus A: vesicular diseases,
meningitis; coxsackievirus B (body):
pleurodynia, myocarditis
Other echovirus and enteroviruses: like
coxsackievirus
Rhinoviruses: common cold, acid labile, does
not replicate above 33° C
Biology, Virulence, and Disease
• Small size, icosahedral capsid, positive RNA
genome with terminal protein
• Genome is sufficient for infection
• Encodes RNA-dependent RNA polymerase,
replicates in cytoplasm
Enteroviruses
• Capsid virus resistant to inactivation
• Disease due to lytic infection of important
target tissue
• Polio: cytolytic infection of motor neurons of
anterior horn and brainstem, paralysis
• Coxsackievirus A: herpangina, hand-foot-
and-mouth disease, common cold,
meningitis
• Coxsackievirus B: pleurodynia, neonatal
myocarditis, type 1 diabetes
Rhinoviruses
• Acid labile and cannot replicate at body
temperature
• Restricted to upper respiratory tract
• Common cold
Epidemiology
• Enteroviruses transmitted by fecal-oral route
and aerosols
• Rhinoviruses transmitted by aerosols and
contact
Diagnosis
• Immune assays (ELISA) or RT-PCR genome
analysis of blood, CSF, or other relevant
sample
Treatment, Prevention, and Control
• OPV and IPV polio vaccines
P
icornaviridae is one of the largest families of viruses and
includes some of the most important human and animal
viruses (Box 46-1). As the name indicates, these viruses are
small (pico) ribonucleic acid (RNA) viruses that have a
naked capsid structure. The family has more than 230
members divided into nine genera, including Enterovirus,
Rhinovirus, Hepatovirus (hepatitis A virus; discussed in
Chapter 55), Cardiovirus, and Aphthovirus. The enterovi-
ruses are distinguished from the rhinoviruses by the stabil-
ity of the capsid at pH 3, the optimum temperature
for growth, the mode of transmission, and their diseases
Adenoviridae is a group of medium sized, non-enveloped, double stranded DNA viruses that replicate and produce disease in the eye and in the respiratory, gastrointestinal and urinary tracts;
A picornavirus is a virus belonging to the family Picornaviridae, a family of viruses in the order Picornavirales. Vertebrates, including humans, serve as natural hosts. Picornaviruses are nonenveloped viruses that represent a large family of small, cytoplasmic, plus-strand RNA viruses with a 30-nm icosahedral capsid.
Polio: flaccid paralysis, major and minor
disease, fecal-oral
Coxsackievirus A: vesicular diseases,
meningitis; coxsackievirus B (body):
pleurodynia, myocarditis
Other echovirus and enteroviruses: like
coxsackievirus
Rhinoviruses: common cold, acid labile, does
not replicate above 33° C
Biology, Virulence, and Disease
• Small size, icosahedral capsid, positive RNA
genome with terminal protein
• Genome is sufficient for infection
• Encodes RNA-dependent RNA polymerase,
replicates in cytoplasm
Enteroviruses
• Capsid virus resistant to inactivation
• Disease due to lytic infection of important
target tissue
• Polio: cytolytic infection of motor neurons of
anterior horn and brainstem, paralysis
• Coxsackievirus A: herpangina, hand-foot-
and-mouth disease, common cold,
meningitis
• Coxsackievirus B: pleurodynia, neonatal
myocarditis, type 1 diabetes
Rhinoviruses
• Acid labile and cannot replicate at body
temperature
• Restricted to upper respiratory tract
• Common cold
Epidemiology
• Enteroviruses transmitted by fecal-oral route
and aerosols
• Rhinoviruses transmitted by aerosols and
contact
Diagnosis
• Immune assays (ELISA) or RT-PCR genome
analysis of blood, CSF, or other relevant
sample
Treatment, Prevention, and Control
• OPV and IPV polio vaccines
P
icornaviridae is one of the largest families of viruses and
includes some of the most important human and animal
viruses (Box 46-1). As the name indicates, these viruses are
small (pico) ribonucleic acid (RNA) viruses that have a
naked capsid structure. The family has more than 230
members divided into nine genera, including Enterovirus,
Rhinovirus, Hepatovirus (hepatitis A virus; discussed in
Chapter 55), Cardiovirus, and Aphthovirus. The enterovi-
ruses are distinguished from the rhinoviruses by the stabil-
ity of the capsid at pH 3, the optimum temperature
for growth, the mode of transmission, and their diseases
Adenoviridae is a group of medium sized, non-enveloped, double stranded DNA viruses that replicate and produce disease in the eye and in the respiratory, gastrointestinal and urinary tracts;
Poxviruses are brick or oval-shaped viruses with large double-stranded DNA genomes. Poxviruses exist throughout the world and cause disease in humans and many other types of animals. Poxvirus infections typically result in the formation of lesions, skin nodules, or disseminated rash.
Largest viruses that infect vertebrates
Can be seen under light microscope
Poxvirus diseases are characterized by skin lesions – localized or generalized
Important diseases caused by poxviruses are-
Smallpox
Monkeypox
Cowpox
Tanapox
Molluscum contagiosum
LUMEN DWELLING FLAGELLATES - GIARDIA
REFS:
INTERNATIONALLY ACCEPTED BOOK OF MEDICAL PARASITOLOGY BY K. D. CHATTERJEE
TEXT BOOK OF MEDICAL PARASITOLOGY BY PANIKER
IMAGE SOURCES : FROM INTERNET
Poxviruses are brick or oval-shaped viruses with large double-stranded DNA genomes. Poxviruses exist throughout the world and cause disease in humans and many other types of animals. Poxvirus infections typically result in the formation of lesions, skin nodules, or disseminated rash.
Largest viruses that infect vertebrates
Can be seen under light microscope
Poxvirus diseases are characterized by skin lesions – localized or generalized
Important diseases caused by poxviruses are-
Smallpox
Monkeypox
Cowpox
Tanapox
Molluscum contagiosum
LUMEN DWELLING FLAGELLATES - GIARDIA
REFS:
INTERNATIONALLY ACCEPTED BOOK OF MEDICAL PARASITOLOGY BY K. D. CHATTERJEE
TEXT BOOK OF MEDICAL PARASITOLOGY BY PANIKER
IMAGE SOURCES : FROM INTERNET
Arthropods form a major group of disease vectors with mosquitoes, flies, sand flies, lice, fleas, ticks and mites transmitting a huge number of diseases.
Many such vectors are haematophagous, which feed on blood at some or all stages of their lives.
Resumen de enfermedades emergentes causadas por el arbovirus, que se transmiten a través de picaduras de mosquito. La posibilidad de afectación de los niños y de las mujeres embarazadas es una realidad que los pediatras tenemos que conocer.
A mosquito-borne viral disease occurring in tropical and subtropical areas.
Spreads by animals or insects
Requires a medical diagnosis
Lab tests or imaging often required
Short-term: resolves within days to weeks
Those who become infected with the virus a second time are at a significantly greater risk of developing severe disease.
Symptoms include high fever, headache, rash and muscle and joint pain. In severe cases there is serious bleeding and shock, which can be life threatening.
Treatment includes fluids and pain relievers. Severe cases require hospital care.
As an intern house officer, I prepared this presentation after I came across a rare case of dengue fever complicated by hemophagocytic lymphohistiocytosis (HLH). Dengue fever itself is a rare disease entity in the UAE, as a developed country; and the presence of such a complication merely added to the complexity of the diagnosis. Therefore, I am delighted to share this lively PowerPoint Presentation about dengue, which was initially supplemented with an interesting case presentation but was removed for confidentiality purposes when sharing the document. I hope you enjoy it!
PS: Use the slideshow button in Microsoft PowerPoint for the best experience.
Now a days.All the World is facing a serious problem..Dengue
so i make a presentation on dengue to prevent and aware from dengue...and if you have dengue faver then which types of treatment you use for your Health.
Dengue fever is the fastest emerging arboviral infection spread
by Aedes mosquitoes with major public health consequences in
over 100 tropical and sub-tropical countries in South-East Asia,
the Western Pacific, and South and Central America. Up to 2.5
billion people globally live under the threat of dengue fever and its
severe forms—dengue hemorrhagic fever (DHF) or dengue shock
syndrome (DSS). More than 75% of these people, or approximately
1.8 billion, live in the Asia-Pacific Region. As the disease spreads to
new geographical areas, the frequency of the outbreaks is increasing
along with changing disease epidemiology. It is estimated that 50
a million cases of dengue fever occur worldwide annually and half a
million people suffering from DHF require hospitalization each year,
a very large proportion of whom (approximately 90%) are children
less than five years old. About 2.5% of those affected with dengue
die of the disease.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
2. Arthropod-borne Viruses
Arboviruses belong to three families
1. Togaviruses e.g. EEE, WEE, and VEE
2. Bunyaviruses e.g. Sandfly Fever, Rift
Valley Fever, Crimean-Congo Haemorrhagic
Fever
3. Flavivirus e.g. Yellow
Fever, Dengue, Japanese
Encephalitis Dr.T.V.Rao MD 2
4. Arboviruses
• The Arbovirus are also called
as Arthropod borne
viruses, represent an
ecological grounding of viruses
with complex transmission
cycles involving Arthropods
• These viruses have diverse
physical and chemical
properties and are classified in
several virus families.Dr.T.V.Rao MD 4
5. History - Dengue
• This disease was first described
1780, and the virus was isolated by
Sabin 1944. Dengue virus infection is
the most common arthropod-borne
disease worldwide with an increasing
incidence in the tropical regions of
Asia, Africa, and Central and South
America.
Dr.T.V.Rao MD 5
6. Over view of Dengue
• With more than one-third of the world’s
population living in areas at risk for
transmission, dengue infection is a
leading cause of illness and death in the
tropics and subtropics. As many as 100
million people are infected yearly.
Dengue is caused by any one of four
related viruses transmitted by
mosquitoes Dr.T.V.Rao MD 6
7. Dengue
• Dengue is the biggest Arbovirus problem in the
world today with over 2 million cases per year.
Dengue is found in SE Asia, Africa and the
Caribbean and S America.
• Flavivirus, 4 serotypes, transmitted by Aedes
mosquitoes which reside in water-filled
containers.
• Human infections arise from a human-mosquitoe-
human cycle
Dr.T.V.Rao MD 7
8. Current Trends
• In the 1980s, DHF began a second
expansion into Asia when Sri
Lanka, India, and the Maldives
Islands had their first major DHF
epidemics; Pakistan first reported
an epidemic of dengue fever in
1994..
Dr.T.V.Rao MD 8
10. Dengue Infection and
Implications
• Dengue virus (DENV) infects 50
million (WHO) to 100 million
(NIH) people annually..
DENV infection can cause dengue
fever, dengue haemorrhagic
fever, dengue shock
syndrome, and death.
Dr.T.V.Rao MD 10
12. What causes Dengue
• Dengue (DF) and dengue haemorrhagic
fever (DHF) are caused by one of four
closely related, but antigenic ally
distinct, virus serotypes (DEN-1, DEN-
2, DEN-3, and DEN-4), of the genus
Flavivirus. Infection with one of these
serotypes provides immunity to only that
serotype for life,
Dr.T.V.Rao MD 12
13. Aedes aegypti – Vector
• Aedes aegypti, a
domestic, day-biting
mosquito that
prefers to feed on
humans, is the most
common Aedes
species. Other
species of Aedes can
also transmit.
Dr.T.V.Rao MD 13
14. Dengue Virus – A Flavivirus
• Flavivirus are
spherical and 40- 60
mm in diameter.
Genome – Positive
sense, single sense
RNA,11kb in size
Genome – RNA
infectious
Enveloped virus
Dr.T.V.Rao MD 14
15. How Mosquitos spread the infection
• The disease starts during the rainy
season, when vector Mosquito
Aedes aegypti is abundant
• The Aedes breeds in the tropical or
semitropical climates in water
holding receptacles or in plants close
to human dwellings
Dr.T.V.Rao MD 15
16. Cycle of Infection Continues
• A female Aedes acquires the
infection feeding upon a viremic
human.
• After a period of 8 – 14 days
mosquitoes are infective and
remain infective for life. ( 1- 3 )
months. Dr.T.V.Rao MD 16
17. Pathogenesis
• Presence of existing Dengue
antibody, associated with fresh viral
infection with new serotype complexes
and forms within few days of the second
dengue infection.
• Non neutralizing enhancing antibodies
promote infection of higher number of
Mononuclear cells.
Dr.T.V.Rao MD 17
18. Immunology Dengue
• Four serotypes exist distinguished by
Molecular basis and Nt tests
• Infection confers life long immunity
• But cross protection between serotypes
is of short duration.
• Reinfection with different serotype after
primary attack is more dangerous
causes Dengue hemorrhagic fever.
Dr.T.V.Rao MD 18
19. Clinical Manifestations
• Any or few of the following events can
occur.
• Fever,
• Severe head ache
• Muscle and joint pains
• Nausea, vomiting,
• Eye pain
Dr.T.V.Rao MD 19
20. How Dengue Infection starts and
manifests
• Incubation period 4 – 7 days ( 3 – 14 days)
• Fever may start with, Malise,chills,head ache
• Soon leads to severe back ache, joint
pains, muscular pain, pain in the eye ball.
• Temperature may persist for 3 -5 days.
• Myalgia may be severe with deep bone pain
( Break bone fever ) characteristic of the
Disease
Dr.T.V.Rao MD 20
23. Dengue Hemorrhagic Fever
• DHF was first recognized in the 1950s during
the dengue epidemics in the Philippines and
Thailand. Today emerging DHF cases are
causing increased dengue epidemics in the
Americas, and in Asia, where all four dengue
viruses are endemic, DHF has become a
leading cause of hospitalization and death
among children in several countries. ( WHO )
Dr.T.V.Rao MD 23
24. Dengue Hemorrhagic Fever
• Common in children.
• In children passively acquired contributed by the
maternal antibodies transferred to the fetus.
• In other ( Adults ) the presence of antibodies due
to previous infection with different serotype
• Initially presents like classical Dengue infection
• But patients condition abruptly worsens, an
important cause of morbidity and mortality in
Dengue
Dr.T.V.Rao MD 24
25. Basic Understanding of Dengue
Hemorrhagic Fever
• Dengue Hemorrhagic Fever is a probable case of
dengue and
• hemorrhagic tendency evidenced by one or more
of the following:
• Ø Positive tourniquet test
• Ø Petechial, ecchymosis or purpura
• Ø Bleeding from mucosa (mostly epistaxis or
bleeding from
• gums), injection sites or other sites
• Ø Haematemesis or melena
Dr.T.V.Rao MD 25
26. How to do a Tourniquet test
• The tourniquet test is
performed by inflating a
blood pressure cuff to a
point mid-way between the
systolic and diastolic
pressures for five minutes.
A test is considered positive
when 10 or more petechiae
per 2.5 cm2 (1 inch) are
observed. In DHF, the test
usually gives a definite
positive result (i.e. >20
petechiae).
Dr.T.V.Rao MD 26
27. What Happens in Dengue
Hemorrhagic Fever
• Thrombocytopenia (platelets 100,000/cu.mm or less)
and Ø Evidence of plasma leakage due to increased
capillary permeability manifested by one or more of
the following:
• – A >20% rise in hematocrit for age and sex
• – A >20% drop in hematocrit following treatment
with
• fluids as compared to baseline
• – Signs of plasma leakage (pleural effusion, ascites or
• hypoproteinaemia).
Dr.T.V.Rao MD 27
28. Risk factor for DHF
• Important risk
factors for DHF
include the strain of
the infecting virus, as
well as the age, and
especially the prior
dengue infection
history of the patient
Dr.T.V.Rao MD 28
29. Dengue Hemorrhagic Syndrome
• Chateresied by shock
and
hemoconcentration
• Contributed by
circumstantial
evidence suggests
secondary infection
with Dengue type 2
following type 1
infection in the past.Dr.T.V.Rao MD 29
30. Dengue hemorraghigic Syndrome
• DHS is caused due to release of,
1 Release of cytokines
2 Vasoactive mediators.
3 Procoagulants
Manifest with disseminated
intravascular coagulation
Dr.T.V.Rao MD 30
31. Diagnosis
In resource rich establishments
1 Reverse transcriptase polymerase chain
reaction methods help rapid identification
2 Isolation of virus is difficult
3 The current favored approach is inoculation
of mosquito cell line with patient serum
coupled with nucleic acid assay to identify a
recovered virus.
Dr.T.V.Rao MD 31
32. Dengue Serology
• The serology is limited with cross reactivity of
IgG antibodies to heterologous Flavivirus
antigens
• Most commonly used methods are
Viral protein specific capture IgM or IgG by
ELISA
IgM antibodies develop within few days of
illness
Neutralizing anti Haemagglutination inhibiting antibodies
appear within a week after onset of Dengue feverDr.T.V.Rao MD 32
33. Importance of paired sample
testing in Serology
• Testing one sample for serum and
reporting a negative test is fallacious
• Analysis of paired acute and
convalescent sera to show
significant rise in antibody titer is
the most reliable evidence of an
active dengue infection.
Dr.T.V.Rao MD 33
34. Newer Diagnostic Methods
RT - PCR
• RT PCR is a highly
sensitive tool in
Diagnosis, with
established high
sensitivity in
Diagnosis in Puzzles
• Developing world
lacks resources to
implement and
utilize the Scientific
advances
Dr.T.V.Rao MD 34
35. Treatment
• No Anti viral therapy
available
• Symptomatic management
in Majority of cases
• Dengue Hemorrhagic fever
to be treated with suitable
fluid replacement
• No Vaccine
available, difficult in view of
four serotypes.
Dr.T.V.Rao MD 35
36. Control of Dengue
• Control of Mosquito breeding
places.
• Anti mosquito measures
• Use of Insecticides.
• Screened windows and doors can
reduce exposure to vectors.
Dr.T.V.Rao MD 36
37. Epidemiology - Dengue
• Dengue virus are distributed world wide
in tropical regions.
• Where the Aedes vectors exist, are
endemic areas
• Changing and increasing incidences are
associated with rapid urban population
growth, over crowding and lax mosquito
control measures
Dr.T.V.Rao MD 37
39. Viral Haemorrhagic Fevers
• Acute infection:
fever, myalgia, malaise; progression to prostration
• Small vessel involvement:
increased permeability, cellular damage
• Multisystem compromise (varies with pathogen)
• Hemorrhage may be small in volume
(indicates small vessel involvement, thrombocytopenia)
• Poor prognosis associated with:
shock, encephalopathy, extensive hemorrhage
Dr.T.V.Rao MD 39
40. Viral Hemorrhagic Fevers
• Diverse group of illnesses caused by RNA viruses from 4
families:
– Arenaviridae, Bunyaviridae, Filoviridae, Flaviridae
– Differ by geographic occurrence and
vector/reservoir
– Share certain clinical and pathogenic features
• Potential for aerosol dissemination, with human infection via
respiratory route (except dengue)
• Target organ: vascular bed
• Mortality 0.5 - 90%, depending on agent
Dr.T.V.Rao MD 40
43. Viral Hemorrhagic Fevers
Transmission
• Zoonotic diseases
– Rodents and arthropods main reservoir
– Humans infected via bite of infected arthropod, inhalation of
rodent excreta, or contact with infected animal carcasses
• Person-to-person transmission possible with
several agents
– Primarily via blood or bodily fluid exposure
– Rare instances of airborne transmission with arenaviruses and
filoviruses
• Rift Valley fever has potential to infect domestic
animals following a biological attack
Dr.T.V.Rao MD 43
44. Viral Hemorrhagic Fevers
Clinical Presentation
• Clinical manifestations nonspecific, vary by
agent
• Incubation period 2-21 days, depending on
agent
• Onset typically abrupt with
filoviruses, flaviviruses, and Rift Valley fever
• Onset more insidious with arenaviruses
Dr.T.V.Rao MD 44
46. VHF Surveillance:
Clinical Identification of Suspected Cases
• Clinical criteria:
– Temperature 101 F(38.3 C) for <3 weeks
– Severe illness and no predisposing factors for
hemorrhagic manifestations
– 2 or more of the following:
• Hemorrhagic or purple rash
• Epistaxis
• Hematemesis
• Hemoptysis
• Blood in stools
• Other hemorrhagic symptoms
• No established alternative diagnosis
JAMA 2002;287
Adapted from WHO
Dr.T.V.Rao MD 46
47. Viral Hemorrhagic Fevers
Treatment
• Supportive care
• Correct coagulopathies as needed
• No antiplatelet drugs or IM injections
• Investigational treatments, available under protocol:
– Ribavirin x 10 days for Arenaviridae and Bunyaviridae
– Convalescent plasma w/in 8d of onset for AHF
Dr.T.V.Rao MD 47
48. Viral Hemorrhagic Fevers
Management of Exposed Persons
• Medical surveillance for all potentially exposed
persons, close contacts, and high-risk contacts
(i.e., mucous membrane or percutaneous exposure) x 21
days
– Report hemorrhagic symptoms (slide 47)
– Record fever 2x/day
• Report temperatures 101 F(38.3 C)
Initiate presumptive ribavirin therapy
• Percutaneous/mucocutaneous exposure to blood or
body fluids of infected:
– Wash thoroughly with soap and water, irrigate mucous membranes with
water or saline
Dr.T.V.Rao MD 48
49. Viral Hemorrhagic Fevers
Infection Control
• Airborne & contact precautions for health care, environmental, and
laboratory workers
• Negative pressure room, if available
– 6-12 air changes/hour
– Exhausted outdoors or through HEPA filter
• Personal protective equipment
– Double gloves
– Impermeable gowns, leg and shoe coverings
– Face shields and eye protection
– N-95 mask or PAPR
Dr.T.V.Rao MD 49
50. Tick Borne Hemorrhagic Fevers
• Kyasanur Forest Disease,
• ( Karnataka India )
• Like Russian Spring Summer Encephalitis,
• Present with
Fever, Headache, Conjunctivitis,
Myalgia, Severe prostration,
Dr.T.V.Rao MD 50
51. Viral Hemorrhagic Fevers
Summary of Key Points
• A thorough travel and exposure history is key to
distinguishing naturally occurring from
intentional viral hemorrhagic fever cases.
• Viral hemorrhagic fevers can be transmitted via
exposure to blood and bodily fluids.
Dr.T.V.Rao MD 51
52. Pathogenesis.
• Enters through the bite of Insect vector,
• Multiply in RES.
• Target the organ
CNS Encephalitis,
Liver Yellow fever,
Capillary endothelium in
Hemorrhagic fevers.
Dr.T.V.Rao MD 52
54. Hanta Viruses,
• Human disease Hemorrhagic fever with renal
syndrome
• Hanta virus pulmonary syndrome.
• Spread by inhalation of Aerosols of Rodent
Excreta,
• Renal Involvement and failure
• Lead to Hemorrhagic shock, Korea
• Spread by Rats carried in ships,
Dr.T.V.Rao MD 54
57. Filoviruses,
African Hemorrhagic Fevers.
• Most important Diseases are
• Marburg and Ebola.
• The nature of Viruses are 80 nm
Filamentous threads,
• Produce Internal and external
Bleeding.
Dr.T.V.Rao MD 57
58. Filoviruses. Marburg
• Marburg 1967 African Green
Monkey,
• Bat – Rodent – Host Human.
• East Africa Monkey – Humans.
Dr.T.V.Rao MD 58
59. Filoviruses - Ebola
• Incubation 2-21 days
• Carries 80% mortality.
• Barrier Nursing Most essential.
• ELISA test
• Culturing Hazardous.
• RT-PCR
• Transporting and carrying Primates is
Hazardous
Dr.T.V.Rao MD 59
65. Rift Valley Fever: Clinical features
• 3-7 day incubation, 3-5 day duration
• Asymptomatic or mild illness
• Fever, myalgia, weakness, weight loss
• Photophobia, conjunctivitis
• Encephalitis
• <5% hemorrhagic fever
• 1-10% vision loss (retinal hemorrhage, vasculitis)
Dr.T.V.Rao MD 65
66. CRIMEAN CONGO HEMORRHAGIC FEVER
(CCHF)
• Extensive geographic distribution
(Africa, Balkans, and western Asia)
• Transmission:
– Tick-borne (Hyalomma spp.)
– Contact with animal blood or products
– Person-to-person transmission
by contact with infectious body fluids
– Laboratory worker transmission
documented
• Mortality 15-40%
• Therapy: RibavirinDr.T.V.Rao MD 66
67. CCHF: Pathogenesis
• Viremia present throughout disease
• IFA becomes positive in patients destined to survive days 4-
6, often simultaneously with Viremia
• Recovery may be due to CMI or neutralizing antibodies
• Patients that die usually still Viremia
• Virus grows in macrophages and other cells
• DIC often present
• Poor prognosis signaled by early elevated AST and clotting
Dr.T.V.Rao MD 67
68. CCHF: Clinical features
• 4-12 day incubation after tick exposure
• 2-7day incubation after direct contact with infected
fluids
• Abrupt onset fever, chills, myalgia, severe headache
• Malaise, GI symptoms, anorexia
• Leukopenia, thrombocytopenia, hemoconcentration, pro
teinuria, elevated AST
• Hemorrhages may be profuse (hematomas, ecchymoses)
Dr.T.V.Rao MD 68
69. PREVENTION OF CCHF
• DEET repellents for skin
• Permethrin repellents for clothing –
(0.5% permethrin should be applied to clothing
ONLY)
• Check for and remove ticks at least twice daily.
• If a tick attaches, do not injure or rupture the
tick.
Remove ticks by grasping mouthparts at the skin
surface using forceps and apply steady traction.
Dr.T.V.Rao MD 69
72. South American Hemorrhagic Fevers:
Clinical features
• 70% Recovery in 7-8 days without
sequelae, prolonged fatigue and weakness
common.
• Severe disease
– Severe hemorrhage
– Delerium, coma, convulsions
– Combined hemorrhagic/neurologic disease
• High mortality Dr.T.V.Rao MD 72
73. • Rule out or treat febrile illnesses:
malaria, rickettsia, leptospirosis, typhoid, dysentery
• Early hospitalization
• Distant medical evacuation associated with high
mortality
• Cautious sedation and analgesia
• Careful hydration
• Pressors, cardiotonic drugs
• Support of coagulation system
VHF: Supportive therapy
Dr.T.V.Rao MD 73
74. Ribavirin
• Guanosine nucleoside analog:
blocks viral replication by inhibiting IMP
dehydrogenase
• Licensed for treatment of RSV and HCV
• Potential adverse effects:
• Dose dependent reversible anemia
• Pancreatitis
• Teratogen in rodents
Dr.T.V.Rao MD 74
75. • Programme Created by Dr.T.V.Rao
MD for Medical Students in the
Developing World
• Email
• doctortvrao@gmail.com
Dr.T.V.Rao MD 75