RESUMO
During 1990, sensitivity of P. falciparum to antimalarials was conducted in Mawlamyaing, Lashio and Seik Phyu townships. There were 40 successful in vitro test in Mawlamyaing, 39 in Lashio, 26 in Seik Phyu township. Chloroquine was found to be highly resistant (95 to 100 Percent) in Mawlamyaing and Lashio areas but 31 Percent sensitivity was detected in Seik Phyu township. Amodiaquine was found to be much more sensitive (38 to 67 Percent) than chloroquine. Effective concentration (EC99) for chloroquine varies from 7.4 to 8.4 U mol/L and EC99 for amodiaquine varies from 0.58 to 1.6 U mol/L. In all the areas studied sulfadoxine/pyrimethamine sensitivity was seen in 65 to 80 Percent. All the isolates from the three areas were 100 Percent sensitive to mefloquine and were also highly sensitive (93 to 100 Percent) to quinine. EC99 of quinine varies from 1.35 to 2.7 U mol/L and EC99 of mefloquine varies from 1.5 to 2.2 U mol/L in the areas.