Babesiosis
Background
- Babesiosis is an infection of the Babesia species of intraerythrocytic protozoa, causing lysis of host red blood cells.
- Spread by the deer tick (Ixodes scapularis)
- People often unaware they are bitten
- Natural reservior is the white footed mouse
- Endemic in US, Europe, parts of Russia and China
- Babesia Microti is pathogen in US
- Possible to have co-infection with Lyme (same tick family)
Clinical Features
- Fever, hemolytic anemia, chills, thrombocytopenia, DIC
- More severe disease in immunocompromized patients (HIV, Elderly, Asplenic)
Differential Diagnosis
Tick Borne Illnesses
- Babesiosis
- Colorado tick fever
- Ehrlichiosis
- Heartland virus
- Lyme
- Murine typhus
- Rocky mountain spotted fever
- Southern tick-associated rash illness (STARI)
- Tick paralysis
- Tularemia
Evaluation
- CBC
- Often with depressed white count
- Peripheral Blood Smears
- Shows intracellular parasites: Maltese Cross sign
- May need large smear as parasitemia can be as low as 1%
- Can often be confused for malaria parasites
- Electrolytes and renal function
- LFTs
- Total bilirubin and haptoglobin values reflect the intensity of the infection (hemolysis)
- Lyme
- Urine - hemolysis
- CXR - rare but possible ARDS
Management
Each regimen is for 10 days duration and option 1 is often used for mild parasitemia <4% with option two for severe cases with >4% parasite load
Option 1
- Atovaquone 750mg BID x 10 days and Azithromycin 500-1000mg day 1 then 250-1000mg daily x 10 days[1]
Option 2
- Clindamycin 600mg PO q8hrs x 7-10 days (or 300-600mg IV q6hrs)
- Give with Quinine 650mg TID
Pediatrics
- Clindamycin 20-40mg/kg/day PO divided TID x 7-10 days (max 600mg/dose)
- Quinine 8mg/kg PO q8h x 7-10 days (Max: 648mg/dose)
Disposition
Admission
- Severe anemia (hemoglobin <10g/dL)
- Parasitemia >4%
- Mortality risk higher in asplenic patients
Discharge
- Parasitemia <4%
- Asymptomatic or mild disease with intact spleen
- Discharged patients should follow-up with primary care or infectious disease specialist
See Also
External Links
References
- Tobler WD, Cotton D, Lepore T, Agarwal S, Mahoney EJ. Case Report: Successful non-operative management of spontaneous splenic rupture in a patient with babesiosis. World Journal of Emergency Surgery : WJES. 2011;6:4. doi:10.1186/1749-7922-6-4.
- ↑ Krause PJ, Lepore T, Sikand VK, Gadbaw J Jr, Burke G, Telford SR 3rd, et al. Atovaquone and azithromycin for the treatment of babesiosis. N Engl J Med. Nov 16 2000;343(20):1454-8.