From the Guidelines
The recommended treatment for Babesia is a combination of atovaquone (750 mg orally every 12 hours) and azithromycin (500-1000 mg on day 1, followed by 250-500 mg daily) for 7-10 days, as this regimen has been shown to be effective and well-tolerated 1. This treatment approach is based on the guidelines from the Infectious Diseases Society of America, which recommend the use of atovaquone plus azithromycin as the initial therapy for patients with babesiosis (A-I) 1.
Key Considerations
- For severe cases of babesiosis, an alternative regimen of clindamycin (600 mg orally every 8 hours or 300-600 mg IV every 6 hours) plus quinine (650 mg orally every 6-8 hours) for 7-10 days may be used 1.
- Treatment duration may be extended to 6 weeks for immunocompromised patients, and supportive care, including hydration and antipyretics for fever, is also important.
- Exchange transfusion might be necessary in cases with high parasitemia (>10%), severe hemolysis, or significant organ dysfunction.
Treatment Rationale
The combination of atovaquone and azithromycin targets different aspects of the parasite's metabolism, with atovaquone disrupting electron transport and azithromycin inhibiting protein synthesis, making it difficult for the parasite to survive and reproduce 1.
Special Considerations
- Immunocompromised patients with babesiosis may require higher doses of azithromycin (600–1000 mg per day) and extended treatment duration 1.
- The diagnosis of babesiosis should be based on epidemiologic, clinical, and laboratory information, including microscopic identification of the organism on Giemsa stains of thin blood smears 1.
From the Research
Treatment Options for Babesia
The recommended treatment for Babesia includes:
- A 7-10-day course of clindamycin (600 mg every 6 h) and quinine (650 mg every 8 h) 2
- Azithromycin (500-600 mg on day 1, and 250-600 mg on subsequent days) and atovaquone (750 mg every 12 h), which has been found to be equally effective in treating adults experiencing babesiosis with fewer adverse reactions than clindamycin and quinine 2, 3
- Exchange transfusion, a potentially life-saving therapy for patients suffering from severe disease with high parasitemia (>5%), significant hemolysis, or renal or pulmonary compromise 2, 4, 5
Effectiveness and Safety of Treatment Options
- The combination of atovaquone and azithromycin has been shown to be as effective as clindamycin and quinine in treating babesiosis, with fewer adverse reactions 3
- Atovaquone alone has been effective in treating experimental babesiosis in hamsters, but recrudescences occurred, suggesting the emergence of drug resistance 6
- The combination of atovaquone and azithromycin has been used to treat patients with babesiosis who have failed standard therapy or have become intolerant to such therapy 6, 5
Clinical Outcomes and Mortality
- A retrospective chart review of 62 patients with confirmed babesiosis found that 98% of patients improved and were discharged from hospital or clinic, with a lower overall mortality compared to historical controls 5
- The majority of patients presented with febrile illness, and the median peak parasitemia was 1.3% 5
- Six patients (15%) required exchange transfusion, and one patient (2%) died 5