Babesia microti: Difference between revisions

Revision as of 13:54, 5 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
Can have delayed diagnosis
Symptoms include fatigue, weakness, and malaise, followed by fever and chill, 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
There are some cases of asympatomatic parasitemia
May experience recrudescence after immunosuppression
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
40% develop complications, including ARDS, DIC, CHF, coma, AKI, splenic rupture

Transplacentally-acquired neonatal 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 clinda 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.

@@ Line 1: / Line 1: @@
+== Background ==
-* Causes '''babesiosis'''
+*Causes '''babesiosis'''
-== Microbiology ==
+===Microbiology===
-* Tickborne protozoa
-* Different species of ''Babesia'' exist
-* Seen as Maltese cross on blood smear
+*Tickborne protozoa
-== Epidemiology ==
+*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
+*Tickborne by [[Vector::Ixodes scapularis]]
-=== Other species ===
+*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''
+*''B. duncani'' and ''B. duncani''-type organisms are present in the Pacific Coast
-== Life Cycle ==
+*''B. divergens'' in Europe; rarely ''B. venatorum''
+==Clinical Manifestations==
-[[File:Babesia_LifeCycle_1.gif|Babesia life cycle]]
+*Incubation period [[Usual incubation period::1 to 6 weeks]]
-== Clinical Manifestations ==
+*Can have delayed diagnosis
+*Symptoms include fatigue, weakness, and malaise, followed by fever and chill, 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
+*There are some cases of asympatomatic parasitemia
+*May experience recrudescence after immunosuppression
+*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
+*40% develop complications, including ARDS, DIC, CHF, coma, AKI, splenic rupture
+===Transplacentally-acquired neonatal infection===
-* Incubation period 1 to 6 weeks
-* Can have delayed diagnosis
-* Symptoms include fatigue, weakness, and malaise, followed by fever and chill, 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
-* There are some cases of asympatomatic parasitemia
-* May experience recrudescence after immunosuppression
-* 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
-* 40% develop complications, including ARDS, DIC, CHF, coma, AKI, splenic rupture
+*Five cases
-=== Transplacentally-acquired neonatal infection ===
+*Symptom onset around 3 to 6 weeks
+*Parasitemia 2-15% on diagnosis
+===Other ''Babesia'' species===
-* Five cases
-* Symptom onset around 3 to 6 weeks
-* Parasitemia 2-15% on diagnosis
+*''B. divergens'' usually in aplenic patients, causing fulminant disease
-=== Other ''Babesia'' species ===
+==Diagnosis==
-* ''B. divergens'' usually in aplenic patients, causing fulminant disease
+*Parasites visualized on blood film, with parasitemia from 1 to 20% but as high as 85% in splenectomized patients
-== Diagnosis ==
+==Management==
-* Parasites visualized on blood film, with parasitemia from 1 to 20% but as high as 85% in splenectomized patients
+*Asymptomatic parasitemia: no treatment necessary unless immunocompromised or persists for longer than 3 months
-== Management ==
+*Mild: [[Is treated by::atovaquone]] plus [[Is treated by::azithromycin]]
+*Severe: [[Is treated by::clindamycine]] plus [[Is treated by::quinine]], ± RBC exchange transfusion
-* Asymptomatic parasitemia: no treatment necessary unless immunocompromised or persists for longer than 3 months
+*''B. divergens'': RBC exchange transfusion plus clinda plus quinine
-* Mild: atovaquone plus azithromycin
+*Duration
-* Severe: clindamycine plus quinine, ± RBC exchange transfusion
+**7 to 10 days for most
-* ''B. divergens'': RBC exchange transfusion plus clinda plus quinine
+**Can relapse when immunocompromised, so these patients need 6+ weeks including 2+ weeks without parasitemia
-* Duration
-** 7 to 10 days for most
-** Can relapse when immunocompromised, so these patients need 6+ weeks including 2+ weeks without parasitemia
 {{DISPLAYTITLE:''Babesia microti''}}