Plasmodium knowlesi infection in an Australian soldier following jungle warfare training in Malaysia

An Australian Army soldier developed a fever after returning to Australia following a three-month deployment to Rifle Company Butterworth, Malaysia. Ten days prior to presentation he had participated in jungle warfare training at Burma Camp, Pulada in Johor, Malaysia. No known direct contact was made with monkeys, which were known to be in the area. Earlier he had stopped his doxycycline chemoprophylaxis for a few days during an episode thought to be due to gastroenteritis. Blood examination showed infrequent Plasmodium species ring-stage trophozoites on thick film. As the ring-stage trophozoites were morphologically different from P falciparum, blood was sent to the ADF Malaria and Infectious Disease Institute at Gallipoli Barracks for species confirmation. The soldier was treated with oral artemether-lumefantrine (Novartis, Coartem (R)) and became aparasitemic in two days. Subsequent nucleic acid studies confirmed the diagnosis as Plasmodium knowlesi, a parasite of macaques. Two weeks following treatment he was admitted to the hospital for glandular fever but was shown not to have had a recrudescence of his original infection.