To the Editor: Following the September 11, 2001, attacks on New York and Washington, the International Security Assistance Force (ISAF) was created in Afghanistan in December 2001 with support from 16 nations. By 2006, ISAF support increased to 36 nations, with approximately 115 000 coalition troops serving during this period. Malaria, especially Plasmodium vivax, is prevalent between May and November in all areas of Afghanistan less than 6667 feet above sea level.1 Since 2002, 85 cases of P vivax malaria have been reported in British, German, and US troops that have been linked to military service with ISAF,2-4 and it is likely that additional cases have occurred.