Babesia microti: Difference between revisions
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Babesia microti
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+ | ==Background== |
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− | = Babesiosis (''Babesia microti'') = |
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+ | *Causes '''babesiosis''' |
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− | == Microbiology == |
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+ | ===Microbiology=== |
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− | * Tickborne protozoa |
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− | * Different species of ''Babesia'' exist |
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− | * Seen as Maltese cross on blood smear |
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+ | *Tickborne protozoa |
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− | == Epidemiology == |
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+ | *Different species of ''Babesia'' exist |
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+ | *Seen as Maltese cross on blood smear |
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+ | ===Epidemiology=== |
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− | * Tickborne by ''Ixodes scapularis'' |
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− | * Reservoir is white-footed mice |
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− | * Can be transmitted by blood transfusion and, rarely, transplacentally (5 cases) |
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− | * More common in the northeastern US, including Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin |
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− | ** Highly endemic in Nantucket, Martha's Vineyard, the Elizabeth Islands, Block Island, Shelter Island, eastern Long Island, an Fire Island |
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+ | *Tickborne by [[Vector::Ixodes scapularis]] |
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− | === Other species === |
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+ | *Reservoir is white-footed mice |
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+ | *Can be transmitted by blood transfusion and, rarely, transplacentally (5 cases) |
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+ | *More common in the northeastern US, including Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin |
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+ | **Highly endemic in Nantucket, Martha's Vineyard, the Elizabeth Islands, Block Island, Shelter Island, eastern Long Island, an Fire Island |
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+ | *Has been found in Canada as of 2013, with several case reports from Manitoba and on case report of [[Babesia duncani]] infection in souther Ontario[[CiteRef::yang2021ba]] |
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+ | *Typically takes 36 hours or longer of tick attachment to be transmitted to human host |
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+ | ====Other Species==== |
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− | * ''B. duncani'' and ''B. duncani''-type organisms are present in the Pacific Coast |
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− | * ''B. divergens'' in Europe; rarely ''B. venatorum'' |
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+ | *''B. duncani'' and ''B. duncani''-type organisms are present in the Pacific Coast |
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− | == Life Cycle == |
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+ | *''B. divergens'' in Europe; rarely ''B. venatorum'' |
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+ | ==Clinical Manifestations== |
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− | [[File:Babesia_LifeCycle_1.gif|Babesia life cycle]] |
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+ | *Incubation period [[Usual incubation period::1 to 6 weeks]] |
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− | == Clinical Presentation == |
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+ | **Diagnosis can be delayed |
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+ | **There are some cases of asymptomatic parasitemia |
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+ | **May experience recrudescence after immunosuppression |
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+ | *Symptoms include [[Causes::fatigue]], [[Causes::weakness]], and [[Causes::malaise]], followed by [[Causes::fever]] and chills, [[Causes::arthralgias]], or [[Causes::nausea]] |
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+ | **Fever may be intermittent or persistent, and can be high |
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+ | *Can also cause [[Causes::nuchal rigidity]], [[Causes::sore throat]], [[Causes::dyspnea]], [[Causes::weight loss]], [[Causes::vomiting]], [[Causes::diarrhea]], and dark urine |
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+ | *Occasionally causes [[emotional lability]], [[depression]], [[hyperesthesia]], [[photophobia]], [[conjunctival injection]], [[abdominal pain]], [[petechiae]], and [[ecchymoses]] |
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+ | *May have [[erythema chronicum migrans]] rash in cases of coinfection |
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+ | *Bloodwork shows [[Causes::anemia]], [[Causes::jaundice]], and other evidence of [[Causes::hemolysis]], often with positive [[direct antiglobulin test]] |
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+ | **Also [[Causes::thrombocytopenia]] and liver enzyme abnormalities |
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+ | **If [[neutropenia]], suggests coinfection with anaplasmosis |
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+ | === Prognosis and Complications === |
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− | * Incubation period 1 to 6 weeks |
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− | * Can have delayed diagnosis |
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− | * Symptoms include fatigue, weakness, and malaise, followed by fever and chill, arthralgias, or nausea |
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− | * Fever may be intermittent or persistent, and can be high |
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− | * Can also cause nuchal rigidity, sore throat, dyspnea, weight loss, vomiting, diarrhea, and dark urine |
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− | * Occasionally causes emotional lability, depression, hyperesthesia, photophobia, conjunctival injection, abdominal pain, petechiae, and ecchymoses |
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− | * May have erythema chronicum migrans rash in cases of coinfection |
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− | * There are some cases of asympatomatic parasitemia |
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− | * May experience recrudescence after immunosuppression |
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− | * Bloodwork shows anemia, jaundice and other evidence of hemolysis, often with positive direct antiglobulin test |
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− | ** Also thrombocytopenia and liver enzyme abnormalities |
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− | ** If neutropenia, suggests coinfection with anaplasmosis |
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− | * 40% develop complications, including ARDS, DIC, CHF, coma, AKI, splenic rupture |
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+ | *40% develop complications, including [[ARDS]], [[DIC]], [[CHF]], coma, [[AKI]], splenic rupture |
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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 |
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− | * Symptom onset around 3 to 6 weeks |
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− | * Parasitemia 2-15% on diagnosis |
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+ | *Five cases |
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− | === Other ''Babesia'' species === |
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+ | *Symptom onset around 3 to 6 weeks |
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+ | *Parasitemia 2-15% on diagnosis |
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+ | ===Other ''Babesia'' species=== |
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− | * ''B. divergens'' usually in aplenic patients, causing fulminant disease |
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+ | *''B. divergens'' usually in aplenic patients, causing fulminant disease |
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− | == Diagnosis == |
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+ | ==Diagnosis== |
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− | * Parasites visualized on blood film, with parasitemia from 1 to 20% but as high as 85% in splenectomized patients |
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+ | *Parasites visualized on blood film, with parasitemia from 1 to 20% but as high as 85% in splenectomized patients |
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− | == Management == |
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+ | ==Management== |
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− | * Asymptomatic parasitemia: no treatment necessary unless immunocompromised or persists for longer than 3 months |
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+ | |||
− | * Mild: atovaquone plus azithromycin |
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+ | *Asymptomatic parasitemia: no treatment necessary unless immunocompromised or persists for longer than 3 months |
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− | * Severe: clindamycine plus quinine, ± RBC exchange transfusion |
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+ | *'''Mild''': [[Is treated by::atovaquone]] 750 mg PO q12h plus [[Is treated by::azithromycin]] 500-1000 mg PO once followed by 250-500 mg PO daily for 7 to 10 days |
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− | * ''B. divergens'': RBC exchange transfusion plus clinda plus quinine |
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+ | *'''Severe''': [[Is treated by::clindamycin]] 300-600 mg IV q6h or 600 mg PO q8h plus [[Is treated by::quinine]] 650 mg PO q6-8h |
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− | * Duration |
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+ | **± RBC exchange transfusion if parasitemia ≥10%, severe hemolysis, or pulmonary, renal, or hepatic failure |
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− | ** 7 to 10 days for most |
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+ | *'''''B. divergens''''': RBC exchange transfusion plus [[clindamycin]] plus [[quinine]] |
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− | ** Can relapse when immunocompromised, so these patients need 6+ weeks including 2+ weeks without parasitemia |
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+ | *Duration |
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+ | **7 to 10 days for most |
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+ | **Can relapse when immunocompromised, so these patients need 6+ weeks including 2+ weeks without parasitemia |
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+ | |||
+ | {{DISPLAYTITLE:''Babesia microti''}} |
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+ | [[Category:Vector-borne infections]] |
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+ | [[Category:Haemosporida]] |
Revision as of 12:24, 8 July 2023
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
- Has been found in Canada as of 2013, with several case reports from Manitoba and on case report of Babesia duncani infection in souther Ontario1
- Typically takes 36 hours or longer of tick attachment to be transmitted to human host
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 750 mg PO q12h plus azithromycin 500-1000 mg PO once followed by 250-500 mg PO daily for 7 to 10 days
- Severe: clindamycin 300-600 mg IV q6h or 600 mg PO q8h plus quinine 650 mg PO q6-8h
- ± RBC exchange transfusion if parasitemia ≥10%, severe hemolysis, or pulmonary, renal, or hepatic failure
- 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
References
- ^ Jiayu Yang, Catherine Smith, Anthony Battad. Babesia microti acquired in Canada. Canadian Medical Association Journal. 2021;193(31):E1213-E1217. doi:10.1503/cmaj.201983.