Malaria chemoprophylaxis: in war and peace

Despite recent and largely undeserved adverse publicity, mefloquine remains a useful antimalarial

Although malaria causes most suffering among children in the tropics, it should not be forgotten that it remains a major cause of military casualties. In September 2003, about 300 US Marines and support staff were deployed to Liberia, West Africa. Of those troops who spent at least one night ashore, 69 contracted falciparum malaria, an attack rate of 44%.1 Forty-four required evacuation for medical care to Europe or the United States. While none died, several developed cerebral malaria and required mechanical ventilation. Malaria was also common among Australian Defence Force (ADF) personnel deployed to East Timor between 1999 and 2000, with 385 cases reported, an attack rate of 5%.2 Eighty-four per cent of these cases were caused by Plasmodium vivax, which, while not life-threatening, causes significant morbidity. Relapse of P. vivax infection, caused by the re-emergence into the bloodstream of parasites lying dormant in the liver (so-called hypnozoites), was a major problem in this group, with 96 relapses reported despite 2 weeks of primaquine therapy.2 This pattern of infection is frequently observed in patients who contract malaria elsewhere in Asia and the Pacific, as reported by Charles and colleagues in this issue of the Journal.3