Newswise — SILVER SPRING, MD, Jan. 31, 2014 – Thirty U.S. service members were diagnosed and/or reported with malaria during 2013, the lowest number during a 10-year surveillance period, according to new analysis by the Armed Forces Health Surveillance Center.
Thirty percent of the malaria cases, or nine, in 2013 were caused by Plasmodium Vivax (P.vivax), the common form of malaria, a mosquito-borne parasitic disease, according to the analysis published in the Medical Surveillance Monthly Report, a peer-reviewed journal on illnesses and injuries affecting service members. Eight percent, or eight cases, were caused by P. falciparum, a more deadly species of the disease. The remaining one-third of diagnoses, or 11 cases, was categorized “unspecified” for a cause of species.
This month’s MSMR issue, which is dedicated entirely to the subject of malaria in the military, summarizes diagnoses among U.S. service members during 2013 and compares it to recent experiences. 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.
“In both 2012 and 2013, there were fewer cases of malaria diagnosed and reported among U.S. military members than in any of the previous eight years,” the report noted. But “continued emphasis on standard malaria prevention protocols is warranted. All military members at risk of malaria should be informed in detail of the nature and severity of the risk.”
Of the 30 malaria cases in 2013, over one-third of the infections were considered to have been acquired in Afghanistan (n=11, 37%) and 20 percent in Africa (n=6); three infections (10 percent) were attributed to Korea and one to South and Central America.
In 2013, as in prior years, most U.S. military members diagnosed with malaria were male (93.3%), active component members (90.0%), in the Army (60.0%), of white, non-Hispanic race/ethnicity (60.0%) and in their 20s (56.7%) (Table 1) .
“Numerous factors could contribute to year-to-year changes in numbers of malaria cases,” the report said. “For example, the number of U.S. military members serving in malaria-endemic countries is not constant; and of particular note, there were 29 percent fewer U.S. military personnel in Afghanistan on 30 September of 2012 versus 2011 and an additional 3 percent decrease through 31 July 2013. Annual changes in environmental variables (e.g., humidity, rainfall, temperature) may change the numbers and distribution of mosquitoes capable of transmitting malaria. In Afghanistan, the use of water-filled irrigation ditches and temperature are significant predictors of malaria transmission.”
Another article in the MSMR issue describes two cases of vivax malaria in U.S. Army soldiers who acquired their infections at a training area in the Republic of Korea during 2012. The report provides a historical perspective regarding the epidemiology of temperate climate vivax malaria, particularly in Korea, and relevant aspects of malaria prevention and control.
“Malaria surveillance and control in the Republic of Korea bring to light the key role that military forces play in biosurveillance and global health,” writes Army Col. James Cumming, director of AFHSC’s Global Emerging Infections Surveillance and Response System division, an editorial published in the issue. “The military brings capacity for health surveillance, logistics and delivery of health care services.”