Chloroquine-resistant Plasmodium falciparum malaria in Ethiopia.

Standard triple-dose therapy with chloroquine (25 mg base/kg) failed to clear asexual Plasmodium falciparum parasites from the blood of 22 of 98 patients infected in various parts of Ethiopia and evaluated in Addis Ababa, a malaria-free city. RI to RIII levels of resistance were demonstrated in those patients. The resistant isolates were confined to areas bordering Somalia, Kenya, and Sudan. In in-vitro tests 7 of 10 (70%) isolates were chloroquine-resistant.