Malaria prophylaxis during military operations in Thailand.

Thai soldiers deployed along the Thai-Kampuchean border experience high attack rates of drug-resistant falciparum malaria. Adequate drug prophylaxis has proven difficult with the failure of chloroquine, pyrimethamine/sulfadoxine, and pyrimethamine/dapsone. Under some circumstances, mefloquine, doxycycline, and proguanil/sulfamethoxazole can successfully prevent falciparum malaria in Thailand. Decisions regarding chemoprophylaxis drugs in Thailand depend on a complex interaction of effectiveness, compliance, side effects, and long-term usefulness.