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A Case of Plasmodium vivax Malaria with an 8-month Incubation Period
1)Department of General Medicine and Infectious Disease, Yamanashi Prefectural Central Hospital, 2)Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine
Yutaro AKIYAMA1), Yuki HINATA1), Takahiro MIKAWA1) & Shigeyuki KANO2)
(Received December 5, 2017)
(Accepted March 6, 2018)
Key words: Plasmodium vivax, incubation period, travel history

A 25-year-old Japanese female was admitted with fever, headache and nausea. She had recurrent fever every 48 hours and a CT scan revealed splenomegaly. An automated hematology analyzer displayed an error message of platelet aggregation. The laboratory technician checked a blood smear with a microscope and found Plasmodium parasites. Suspecting malaria infection, we reconfirmed her travel history and found that she had visited India and Nepal 8 months ago. The PCR test revealed that she was infected with Plasmodium vivax (P. vivax) malaria.

The average incubation period is 2-4 weeks for P. vivax malaria, but some cases of P. vivax malaria show a much longer incubation period up to a maximum of about 12 months. When a patient has malaria-like symptoms, it is of utmost importance to confirm his/her travel history within at least the previous 1 year.

[ Kansenshogaku Zasshi 92: 538-541, 2018 ]

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