Plasmodium malariae, a causative agent of quartan malaria, is prevalent across tropical and subtropical regions, but global cases have been usually very rare and sporadic. However, a significant outbreak of quartan malaria caused by P. malariae occurred in Khanh Vinh District, Khanh Hoa Province, Vietnam in 2023 and the outbreak persists. In this report, we present the epidemiological and clinical characteristics of this unprecedented outbreak of quartan malaria in Vietnam.
Keywords: Plasmodium malariae; Vietnam; epidemiology; outbreak; quartan malaria.