Plasmodium vivax malaria complicated by hemophagocytic syndrome in an immunocompetent serviceman

We describe a 23-year-old retired military officer who was immunocompetent but diagnosed with hemophagocytic syndrome (HPS) by Plasmodium vivax infection. Initially, the patient was suspected to have toxic hepatitis related to heavy drinking. But abnormal hematologic findings required a further bone marrow examination and the diagnosis of HPS was made. Antimalarial chemotherapy then brought complete remission. Plasmodium falciparum, a species causing more severe malarial infection, was listed as one of the major causes of HPS. However, P. vivax was not mentioned, and only one case was reported in the literature. In this study, we suggest that P. vivax malaria should be included in the differential diagnosis of HPS, even in an immunocompetent person.