Update: malaria, U.S. Armed Forces, 2013.

U.S. service members are at risk of acquiring malaria infection when they are present in endemic areas because of long term duty assignments, participation in shorter term contingency operations, or personal travel. The numbers of cases among service members in 2012 (n=40) and 2013 (n=30) were the lowest reported during the past ten years. In 2013 over one-third of cases were attributed to service in Afghanistan (n=11) and six cases were linked to Africa. Nine cases were caused by Plasmodium vivax; eight cases were caused by P. falciparum; and one-third were reported as "unspecified" malaria. Malaria was reported from 21 different medical facilities in the United States, Afghanistan, Germany, Italy, Japan, Korea, and Cuba. The relatively low numbers of cases in 2012 and 2013 could reflect a decrease in the number of troops who served in endemic areas, improved or increased use of chemoprophylaxis and personal protective equipment, and changes in environmental factors that may influence the numbers and distribution of infected mosquitoes. Providers of care to military members should be knowledgeable regarding, and vigilant for, clinical presentations of malaria outside of endemic areas.