Malaria in the Australian military, 2008-2022

Australian Defence Force (ADF) personnel train and operate in malarious regions that include neighboring countries with high burden and species with latent hepatic parasites.1 We summarized longitudinal malaria case data, following a prior 10-year period review to 2007.2 Malaria case entries within the ADF Malaria and Infectious Diseases Institute (ADFMIDI)-managed Central Malaria Register (CMR) were examined. Data from cases confirmed between January 1, 2008 through December 31, 2022 were analyzed. Sixty ADF members were diagnosed with malaria, including 1 with a mixed Plasmodium falciparum and P. vivax infection. Of 61 malaria infections, 69% (42 of 61) were P. vivax. P. vivax infection resulted in delayed initial case presentation (more than 4 weeks after exposure) in at least 36% (15 of 42) of cases, and 5 personnel experienced further relapse. Most P. vivax infections were acquired in the U.S. Indo-Pacific Command (INDOPACOM) and P. falciparum in the U.S. Africa Command (AFRICOM) regions. The ADF experienced ongoing reduced malaria case incidence following high rates in the early 2000s. Maintenance of prophylactic vigilance, both for eradicating dormant hypnozoites and preventing P. vivax relapse, remains important, however.