Sensitivity of P. falciparum in Vivo on the Thai-Myanmar Border in 2001 (การศึกษาความไวของเชื้อมาลาเรีย Plasmodium falciparum ต่อยาเมโฟลควิน และไพรมาควิน ในจังหวัดชายแดนไทย-เมียนมาร์ (ด้านจังหวัดระนองและชุมพร))

This in vivo study aimed to assess the sensitivity of falciparum malaria to Mefloquine atRanong and Chumporn provinces along the Thai-Myanmar border from June to December2001. A single dose of 750 mg Mefloquine and 30 mg Primaquine was given to each falciparummalaria case after blood examination at malaria clinic. The subjects were appointed to undergofollow-up both clinical and blood examination at day 2, 3 7, 14, 21, and 28 after the treatment.A total of 42 cases were recruited, about 7.14 and 21.43 percent were absent of parasitemia onday 2 and day 3 respectively. The rates of late treatment failure and adequate clinical responsein this surveillance was 61.90 and 38.09 percent. In conclusion, the effectiveness of Mefloquinein these sentinel sites was declining compared to that in the previous study. It is urgent to havefurther confirmation and revision of anti-malarial drug policy in this area. Key words: falciparum malaria, drug sensitivity, Mefloquine, Thai-Myanmar border