Babesia microti: Difference between revisions
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Babesia microti
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==Background== |
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*Causes '''babesiosis''' |
*Causes '''babesiosis''' |
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**Highly endemic in Nantucket, Martha's Vineyard, the Elizabeth Islands, Block Island, Shelter Island, eastern Long Island, an Fire Island |
**Highly endemic in Nantucket, Martha's Vineyard, the Elizabeth Islands, Block Island, Shelter Island, eastern Long Island, an Fire Island |
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====Other |
====Other Species==== |
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*''B. duncani'' and ''B. duncani''-type organisms are present in the Pacific Coast |
*''B. duncani'' and ''B. duncani''-type organisms are present in the Pacific Coast |
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*Incubation period [[Usual incubation period::1 to 6 weeks]] |
*Incubation period [[Usual incubation period::1 to 6 weeks]] |
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**Diagnosis can be delayed |
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*Can have delayed diagnosis |
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*Bloodwork shows anemia, jaundice and other evidence of hemolysis, often with positive direct antiglobulin test |
*Bloodwork shows [[Causes::anemia]], [[Causes::jaundice]], and other evidence of [[Causes::hemolysis]], often with positive [[direct antiglobulin test]] |
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**Also thrombocytopenia and liver enzyme abnormalities |
**Also [[Causes::thrombocytopenia]] and liver enzyme abnormalities |
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**If neutropenia, suggests coinfection with anaplasmosis |
**If [[neutropenia]], suggests coinfection with anaplasmosis |
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=== Prognosis and Complications === |
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===Transplacentally-acquired neonatal infection=== |
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*More severe illness in patients with [[asplenia]], [[X-linked agammaglobulinemia]], [[malignancy]], [[HIV]] with low CD4 count, [[TNF-α inhibitors]], and immunosuppression for transplantation, [[B-cell lymphoma]], or autoimmune disorders |
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===Congenital Infection=== |
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*Five cases |
*Five cases |
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*Asymptomatic parasitemia: no treatment necessary unless immunocompromised or persists for longer than 3 months |
*Asymptomatic parasitemia: no treatment necessary unless immunocompromised or persists for longer than 3 months |
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*Mild: [[Is treated by::atovaquone]] plus [[Is treated by::azithromycin]] |
*'''Mild''': [[Is treated by::atovaquone]] plus [[Is treated by::azithromycin]] |
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*Severe: [[Is treated by::clindamycine]] plus [[Is treated by::quinine]], ± RBC exchange transfusion |
*'''Severe''': [[Is treated by::clindamycine]] plus [[Is treated by::quinine]], ± RBC exchange transfusion |
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*''B. divergens'': RBC exchange transfusion plus |
*'''''B. divergens''''': RBC exchange transfusion plus [[clindamycin]] plus [[quinine]] |
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*Duration |
*Duration |
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**7 to 10 days for most |
**7 to 10 days for most |
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[[Category:Vector-borne infections]] |
[[Category:Vector-borne infections]] |
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[[Category:Haemosporida]] |
[[Category:Haemosporida]] |
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[[Category:Infectious diseases]] |
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Revision as of 11:56, 21 August 2020
Background
- Causes babesiosis
Microbiology
- Tickborne protozoa
- Different species of Babesia exist
- Seen as Maltese cross on blood smear
Epidemiology
- Tickborne by Ixodes scapularis
- Reservoir is white-footed mice
- Can be transmitted by blood transfusion and, rarely, transplacentally (5 cases)
- More common in the northeastern US, including Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin
- Highly endemic in Nantucket, Martha's Vineyard, the Elizabeth Islands, Block Island, Shelter Island, eastern Long Island, an Fire Island
Other Species
- B. duncani and B. duncani-type organisms are present in the Pacific Coast
- B. divergens in Europe; rarely B. venatorum
Clinical Manifestations
- Incubation period 1 to 6 weeks
- Diagnosis can be delayed
- There are some cases of asymptomatic parasitemia
- May experience recrudescence after immunosuppression
- Symptoms include fatigue, weakness, and malaise, followed by fever and chills, arthralgias, or nausea
- Fever may be intermittent or persistent, and can be high
- Can also cause nuchal rigidity, sore throat, dyspnea, weight loss, vomiting, diarrhea, and dark urine
- Occasionally causes emotional lability, depression, hyperesthesia, photophobia, conjunctival injection, abdominal pain, petechiae, and ecchymoses
- May have erythema chronicum migrans rash in cases of coinfection
- Bloodwork shows anemia, jaundice, and other evidence of hemolysis, often with positive direct antiglobulin test
- Also thrombocytopenia and liver enzyme abnormalities
- If neutropenia, suggests coinfection with anaplasmosis
Prognosis and Complications
- 40% develop complications, including ARDS, DIC, CHF, coma, AKI, splenic rupture
- More severe illness in patients with asplenia, X-linked agammaglobulinemia, malignancy, HIV with low CD4 count, TNF-α inhibitors, and immunosuppression for transplantation, B-cell lymphoma, or autoimmune disorders
Congenital Infection
- Five cases
- Symptom onset around 3 to 6 weeks
- Parasitemia 2-15% on diagnosis
Other Babesia species
- B. divergens usually in aplenic patients, causing fulminant disease
Diagnosis
- Parasites visualized on blood film, with parasitemia from 1 to 20% but as high as 85% in splenectomized patients
Management
- Asymptomatic parasitemia: no treatment necessary unless immunocompromised or persists for longer than 3 months
- Mild: atovaquone plus azithromycin
- Severe: clindamycine plus quinine, ± RBC exchange transfusion
- B. divergens: RBC exchange transfusion plus clindamycin plus quinine
- Duration
- 7 to 10 days for most
- Can relapse when immunocompromised, so these patients need 6+ weeks including 2+ weeks without parasitemia
