SUCCESSFUL PREVENTION AND TREATMENT OF BABESIOSIS WITH ATOVAQUONE

Atovaquone was evaluated for the prevention and treatment of babesiosi s in hamsters. When atovaquone was administered before inoculation of 10(6) Babesia microti and continued for 8 days thereafter, 9 of 10 ham sters survived beyond 54 days, but all untreated controls died within 12 days after inoculation. Quantitation of parasitemia showed a mean o f 75% erythrocytes parasitized by day 5 in controls, but atovaquone re cipients never exceeded 0.7% of parasitized erythrocytes over 54 days of observation, Clindamycin plus quinine was also effective but less s o than atovaquone, When treatment was not started until parasitemia be came established, atovaquone in doses of 300, 150, and 80 mg/kg/day wa s effective in the recovery of all animals compared with 50% of those receiving 10 mg/kg/day and 10% of untreated controls. With its remarka ble safety record, atovaquone offers promise for clinical trials in ba besiosis of both humans and lower animals.