Kansenshōgaku zasshi. The Journal of the Japanese Association for Infectious Diseases
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Kansenshogaku Zasshi · Jul 2013
Case Reports[Plasmodium malariae malaria with more than a 4-month incubation period: difficult to distinguish from a relapse of Plasmodium vivax malaria].
We report herein on a case of Plasmodium malariae malaria with more than a 4-month incubation period. A 35-year-old Japanese man who first presented to our clinic with fever and history of travel to Papua New Guinea was suspected of having Plasmodium vivax malaria based on peripheral smear results. We admitted him and initiated treatment with mefloquine. ⋯ Therefore, the use of these drugs for prophylaxis will not be effective for prevention of malaria if its liver stage is longer than the duration of effective chemoprophylaxis. Although the incubation period of P. malariae is typically 13 to 28 days, it occasionally lasts for months or even years. Careful attention should be given to the possibility that P. malariae occasionally has a long incubation period even in the absence of the hypnozoite stage.