NEW ASPECTS OF MALARIA IMPORTED FROM ETHIOPIA

We describe a high incidence of Plasmodium vivax malaria among travele rs returning from Ethiopia, who all took the recommended prophylaxis. Three groups of 7-11 nonimmune travelers received mefloquine (250 mg w eekly), beginning 1-2 weeks prior to departure and continuing for 4 we eks after their return. A fourth group mistakenly took inadequate prop hylaxis and is presented for comparison. Vivax malaria occurred at a r ate of up to 50% in the first three groups; nearly all patients became ill 3 months after exposure. In the fourth group, primary attacks of both falciparum and vivax malaria occurred within 1 month of return, a t an incidence of 50%. The use of mefloquine prevented Plasmodium falc iparum infection, but a very high rate of relapses of P. vivax infecti on occurred. The complexity of prophylaxis for malaria in an area with a high rate of both P. falciparum and P. vivax infections and the urg ent need for effective causal prophylaxis are discussed.