Babesiosis

GENERAL PRINCIPLES

• Babesiosis is a malaria-like illness that is caused by the intraerythrocytic parasite Babesia microti, a tick-borne protozoan.

• Coinfection with Lyme disease can occur because both are transmitted by the same tick vector (Ixodes ^sPP∙)∙

DIAGNOSIS

• Clinical disease ranges from subclinical to severe, with fever, chills, myalgias, and headache.

• Hemolytic anemia, elevated LDH, transaminitis, and thrombocytopenia are typical laboratory findings.

• Diagnosis is made by visualization of the parasite in erythrocytes on thin blood smears.

• Blood PCR is the most sensitive test.

TREATMENT

• For mild disease, atovaquone 750 mg PO q12h plus azithromycin 500 mg PO on day 1, then 250 mg qday for 7-10 days, is the treatment of choice.

• Severe disease (organ dysfunction, parasitemia >5% or immunosuppressed) should be treated with clindamycin 600 mg IV q8h plus quinine 650 mg PO q8h for 7-10 days. Exchange transfusion may also be needed.

• Longer durations of therapy may be necessary in patients with persistent symptoms or until parasitemia has cleared.⁴⁵