Babesiosis
 Introduction
 History
 Classification
 Structure
 Lifecycle
 Epidemiology
 Pathogenesis
 Clinical features
 Diag...
Introduction
• Infection due to parasites belonging to genus Babesia
•
•
•
•
•
•

•

B. microti
B. divergens
B. duncani
WA...
History

Theobald Smith (July 31, 1859 – December 10, 1934) Along with
Kilbourne Discovered arthropod borne transmission i...
History
 1957- 1st human case- Yugoslavian farmer
 1968- 1st recognized in California (USA)

 1976- Ixodes dammini iden...
Classification
 Taxonomic Classification
 phylum Apicomplexa (also called Sporozoa),
 class Aconoidasida (Piroplasmea)
...
• Initially, Babesia species identified - morphological

parameters of the intraerythrocytic forms
(i.e., trophozoites)
• ...
Large(2.5-5µm)
Transovarial

Small (1.0–2.5µm)
Transstadial

Babesiosis, HOMER et.al. CMR, July 2000, p. 451–469
Structure
Lifecycle

Reservoir
White tailed deer

For all except
B. meri
ornithodorrus
Epidemiology
WA-1

B. microti 300
cases

 Temperate climates

B. divergens
Epidemiology
 Frequency of B. microti & WA-1 in US > reported cases


because self- limiting & mild in humans

 Mortali...
Contd..
 Sporadic cases – Europe (France & British Isles),

Africa, Asia
• Cattle Babesia (B. divergens, B. microti)

 8...
India
 Single case report
 51 year old patient from Madhya Pradesh
 History
 Working nursing home in gwalior
 Fever, ...
 O/E
 Liver and spleen palpable
 Scleral icterus, passed dark coloured urine
 Investigations
 WBC count 1,900/cumm
 ...
 Peripheral blood smear – ring forms varied greatly

confused P. Falciparum
 Antimalarial treatment – no response
 Smea...
Pathogenesis
Env

Host
Agent
 Modification and rupture of RBCs


Replication neoAg`s d/t membrane alteration


Docking sites for IgG and complement...
• establishment stage antibodies (IgG) play a role in

preventing erythrocyte infection by binding the free
sporozoites.
•...
Clinical features
• Disease manifestations asexual reproductive stage
• Predisposing factors +/• Mild to severe illness
– ...
Clinical examination
 Hepatomegaly and splenomegaly
 Hemolytic anemia - lasts from several days to few

months occur in ...
 Pulmonary manifestations - rare in babesiosis, but

non-cardiogenic pulmonary edema (NCPE) is the most
frequent manifest...
Common Complications
 Acute respiratory distress syndrome
 Anemia requiring transfusion
 Congestive heart failure
 Dis...
HUMAN COINFECTION
• Coinfection with B. microti & other tick-borne

pathogens, particularly B. burgdorferi (Lymes disease)...
• Patients coinfected with B. microti and B. burgdorferi

experience
•
•

more severe symptoms, resulting in fatality in r...
Blood
transfusion

Splenectomy

Tick bite

Travel
history
Clinical
presentation

Diagnosis

Age
 A positive Coombs test in combination with hemolytic

anemia & elevated procalcitonin levels is highly
suspicious of bab...
 Examination of thin blood

smears
 most frequently used technique
 Wright’s or Giemsa stain
 simple rings (annular),
...
• Duration of detectable parasitemia on blood smears

varies
•

3 weeks to 12 weeks with the longest duration of smear
pos...
 Distinguishing features differentiate the two

organisms.
 Babesial organisms usually form tetrads ("Maltese

cross"),
...
Serodiagnosis
 IFATs - B. microti infections, chronic infections











Hamster-derived B. microti Ag
Disting...
IFAT
 Antibody titers can remain elevated for as long as 13

months to 6 years after infection
 Although persistence of ...
ELISA
 ELISA – Recombinant antigen - 4 antigens used





rBMN1-2
rBMN1-15
rBMN1-17
rMN-10

- 27/40
- 27/40
- 27/40
-...
Problem associated with
serological tests
•

Relationship between antibody titers, the presence of
parasites, and the stat...
PCR assay
• Based on universal primer amplification of a fragment

of the small subunit rRNA gene
• Highly conserved among...
 Advantages over IFA testing.
 Less time consuming
 conducted by generalist technicians
 more readily be standardized
...
MASP(microaerophilous stationary
phase) culture technique


Quantities of parasite nucleic acid needed for defining
phylo...
Laboratory diagnosis
• B. microti immunoblot kits
• Animal Inoculation
•
•
•

2-4 weeks
Sensitive (300 org./ml blood)
Time...
Animal models
 Rats
 BALB/ c mice
 Splenectomized calves

 Gerbils
Treatment
 Imidocarb and the combination of oxomemazine and

phenamidine were most effective in vitro
 Imidocarb, although not lic...
Prevention
• Avoidance of or minimization of exposure to tick•

•
•
•

infested areas
Ase of tick repellents before enteri...
Vaccines
 Live vaccines


living parasites cattle

 Recombinant vaccines




B. bovis & B. bigemina vaccine cattle
S...
Summary
 Emerging disease
 Common in the Americas
 Can be confused with plasmodium falciparum

infection
 Diagnosis re...
Thank you
Babesiosis
Babesiosis
Upcoming SlideShare
Loading in …5
×

Babesiosis

2,952 views
2,593 views

Published on

My presentation on Babseiosis

Published in: Health & Medicine, Technology
0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
2,952
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
161
Comments
0
Likes
3
Embeds 0
No embeds

No notes for slide

Babesiosis

  1. 1. Babesiosis
  2. 2.  Introduction  History  Classification  Structure  Lifecycle  Epidemiology  Pathogenesis  Clinical features  Diagnosis  Treatment  Animal models  Prevention
  3. 3. Introduction • Infection due to parasites belonging to genus Babesia • • • • • • • B. microti B. divergens B. duncani WA-1 MO-1 KO -1 EU-1 • Obligate intracellular: RBCs • Requires both a competent vertebrate and nonvertebrate host to maintain transmission cycles • Transmitted by ixodid ticks to their vertebrate hosts
  4. 4. History Theobald Smith (July 31, 1859 – December 10, 1934) Along with Kilbourne Discovered arthropod borne transmission in 1893 Cattle Febrile heamturia : Bloodied waters of Egypt
  5. 5. History  1957- 1st human case- Yugoslavian farmer  1968- 1st recognized in California (USA)  1976- Ixodes dammini identified as vector for B. microti  1993- 1st description of WA-1  1996- 1st description of MO-1
  6. 6. Classification  Taxonomic Classification  phylum Apicomplexa (also called Sporozoa),  class Aconoidasida (Piroplasmea)  order Piroplasmida  families Babesiidae and Theileriidae;  absence of a preerythrocytic cycle in Babesia and the absence of transovarial transmission in Theileria.
  7. 7. • Initially, Babesia species identified - morphological parameters of the intraerythrocytic forms (i.e., trophozoites) • This analysis, along with host specificity, has provided > 100 species of Babesia • 7 spp. affect humans
  8. 8. Large(2.5-5µm) Transovarial Small (1.0–2.5µm) Transstadial Babesiosis, HOMER et.al. CMR, July 2000, p. 451–469
  9. 9. Structure
  10. 10. Lifecycle Reservoir White tailed deer For all except B. meri ornithodorrus
  11. 11. Epidemiology WA-1 B. microti 300 cases  Temperate climates B. divergens
  12. 12. Epidemiology  Frequency of B. microti & WA-1 in US > reported cases  because self- limiting & mild in humans  Mortality in USA – 5%  Survey in California – 16% prevalence WA-1  Survey of Blood donors - 3-8% prevalence B. microti  Human cases of B. microti reported Coastal areas of southern New England  Eastern Long Island  Minnesota  Winsconsin   WA-1 – throughout pacific coasts Babesiosis, HOMER et.al. CMR, July 2000, p. 451–469
  13. 13. Contd..  Sporadic cases – Europe (France & British Isles), Africa, Asia • Cattle Babesia (B. divergens, B. microti)  83% Babesiosis in Europe - B. divergens  Mortality rate – 42% Europe  Few cases reported – China, Taiwan, Egypt, S. Africa, Mexico  Transfusion- acquired Babesia several cases in USA, but none in Europe & elsewhere
  14. 14. India  Single case report  51 year old patient from Madhya Pradesh  History  Working nursing home in gwalior  Fever, vomiting, headache, arthralgia  No h/o tick bite or visit to endemic area  No other family member  No h/o splenectomy or blood transfusion IJMM 2005;23:267-9
  15. 15.  O/E  Liver and spleen palpable  Scleral icterus, passed dark coloured urine  Investigations  WBC count 1,900/cumm  Platelet count 55,000/cumm  LDH raised
  16. 16.  Peripheral blood smear – ring forms varied greatly confused P. Falciparum  Antimalarial treatment – no response  Smear reviewed – pear shaped, tetrad - babesiosis suspected  HRP II – negative  Quinine + clindamycin – Pt. afebrile within 2 days
  17. 17. Pathogenesis Env Host Agent
  18. 18.  Modification and rupture of RBCs  Replication neoAg`s d/t membrane alteration  Docking sites for IgG and complement  phagocytosis in spleen  Anemia  Lack of periodicity: Asynchronous replication  More severe manifestations in immunosuppresed and elderly
  19. 19. • establishment stage antibodies (IgG) play a role in preventing erythrocyte infection by binding the free sporozoites. • progression stage organisms invade erythrocyte – innate immune system control growth rate of the merozoites – NK cells and macrophages - soluble factors: IFN-g by NK cells and TNF-a, nitric oxide (NO), and ROSs by macrophages (Mf). • resolution stage decrease in parasite numbers - intracellular degeneration inside the erythrocyte, as evidenced by the appearance of crisis forms.
  20. 20. Clinical features • Disease manifestations asexual reproductive stage • Predisposing factors +/• Mild to severe illness – Generalized weakness – Fever – Gastrointestinal symptoms (anorexia, nausea, abdominal – – – – – – pain, vomiting, diarrhea, etc.) Headache Myalgia Weight loss Arthralgia Respiratory symptoms (cough, shortness of breath, etc.) Dark urine
  21. 21. Clinical examination  Hepatomegaly and splenomegaly  Hemolytic anemia - lasts from several days to few months occur in clinically severe cases, most commonly in asplenic or elderly
  22. 22.  Pulmonary manifestations - rare in babesiosis, but non-cardiogenic pulmonary edema (NCPE) is the most frequent manifestation  not related  degree of parasitemia  splenic function and its onset may be early or late  16 reported cases - reviewing the literature on the pulmonary complications
  23. 23. Common Complications  Acute respiratory distress syndrome  Anemia requiring transfusion  Congestive heart failure  Disseminated intravascular coagulation  Hypotension/shock  Myocardial infarction  Renal failure
  24. 24. HUMAN COINFECTION • Coinfection with B. microti & other tick-borne pathogens, particularly B. burgdorferi (Lymes disease) • serosurveys - 13% of Lyme disease patients in babesia-endemic areas are coinfected with B. microti • B. microti is transmitted by the same Ixodes tick that perpetuates the agents of Lyme disease • human granulocytic ehrlichiosis • novel Bartonella species • • P. leucopus is also the vertebrate reservoir for at least three of the known pathogens
  25. 25. • Patients coinfected with B. microti and B. burgdorferi experience • • more severe symptoms, resulting in fatality in rare cases persistence of postinfectious fatigue. • B. burgdorferi DNA persisted for prolonged periods • B. microti - no significant effect on the duration of parasitemia
  26. 26. Blood transfusion Splenectomy Tick bite Travel history Clinical presentation Diagnosis Age
  27. 27.  A positive Coombs test in combination with hemolytic anemia & elevated procalcitonin levels is highly suspicious of babesiosis  Laboratory tests  examination of stained blood smears  serologic evaluation with indirect (immuno) fluorescent antibody tests (IFATs)  PCR
  28. 28.  Examination of thin blood smears  most frequently used technique  Wright’s or Giemsa stain  simple rings (annular),  pear-shaped (pyriform),  Maltese cross (tetrad form)  High parasitemia present during acute infections  varying from 5 to 80% of erythrocytes
  29. 29. • Duration of detectable parasitemia on blood smears varies • 3 weeks to 12 weeks with the longest duration of smear positivity being 7 months for a splenectomized patient • Quantitative buffy coat system (QBC) – Merozoites stained with acridine orange • • Simple & rapid Showed 100% correlation with blood smear exam. (Mattia et al, 1993)
  30. 30.  Distinguishing features differentiate the two organisms.  Babesial organisms usually form tetrads ("Maltese cross"),  Do not have hemozoin pigments within the affected red blood cells  Have extracellular merozoites
  31. 31. Serodiagnosis  IFATs - B. microti infections, chronic infections         Hamster-derived B. microti Ag Distinguish between B. microti, WA-1, B. divergens Specific and sensitive Diagnostic titers above 1:64 Higher cutoff titers (1:128 to 1:256) greater diagnostic specificity IgM and IgG Problematic in HIV, splenectomy Time consuming & labor intensive
  32. 32. IFAT  Antibody titers can remain elevated for as long as 13 months to 6 years after infection  Although persistence of antibody does not necessarily reflect a measurable infection, levels of IgG antibody decline less rapidly in persistently infected patients
  33. 33. ELISA  ELISA – Recombinant antigen - 4 antigens used     rBMN1-2 rBMN1-15 rBMN1-17 rMN-10 - 27/40 - 27/40 - 27/40 - 27/40  Showed high sensitivity & specificity  Soluble whole parasite antigen (B. divergens) Loades et al, 2000
  34. 34. Problem associated with serological tests • Relationship between antibody titers, the presence of parasites, and the state of protective immunity is not clear • Antibodies may persist for long periods after the disease has cleared • Overestimate of disease prevalence • Antibody titers may be observed in the absence of protective immunity
  35. 35. PCR assay • Based on universal primer amplification of a fragment of the small subunit rRNA gene • Highly conserved among babesias • Heterologous between Babesia spp. and other intraerythrocytic protozoal parasites as well as within the genus Babesia itself • Distinguishes readily between B. divergens, B. microti, and Plasmodium spp., it provides a valuable adjunctive
  36. 36.  Advantages over IFA testing.  Less time consuming  conducted by generalist technicians  more readily be standardized  sensitivity and specificity comparable to those of conventional IFAs
  37. 37. MASP(microaerophilous stationary phase) culture technique  Quantities of parasite nucleic acid needed for defining phylogenetic relationships of these species,  Methods for detection of the parasite in otherwise asymptomatic individuals  Producing parasite antigens  Attenuated strains of Babesia - immunization.
  38. 38. Laboratory diagnosis • B. microti immunoblot kits • Animal Inoculation • • • 2-4 weeks Sensitive (300 org./ml blood) Time consuming, expensive
  39. 39. Animal models  Rats  BALB/ c mice  Splenectomized calves  Gerbils
  40. 40. Treatment
  41. 41.  Imidocarb and the combination of oxomemazine and phenamidine were most effective in vitro  Imidocarb, although not licensed for human use, most effective agent for treating B. divergens infections in cattle  other pharmacologic interventions - chloroquine, tetracycline, primaquine, sulfadiazine, an d pyrimethamine
  42. 42. Prevention • Avoidance of or minimization of exposure to tick• • • • infested areas Ase of tick repellents before entering a tick-infested area thorough examination of skin after exposure. Ticks found before attachment -removed, and Ticks found after attachment removed within 24 h limit the possibility of transmission Application of pesticide to host nests and on the coats of reservoir hosts can interrupt transmission
  43. 43. Vaccines  Live vaccines  living parasites cattle  Recombinant vaccines    B. bovis & B. bigemina vaccine cattle Soluble parasite antigen (SPA) No effective B. microti vaccine  Human vaccines – Expt. Stage   MRA gene (Maltase cross form-related antigen) 37 kDa glycoprotein (Bd37)
  44. 44. Summary  Emerging disease  Common in the Americas  Can be confused with plasmodium falciparum infection  Diagnosis requires high index of suspicion  Treatment involves use of At or Az or Clin + Quin
  45. 45. Thank you

×