title: First case of Plasmodium knowlesi infection in a Japanese traveller returning from Malaysia.
abstract: This is the first case of Plasmodium knowlesi infection in a Japanese traveller returning from Malaysia. In September 2012, a previously healthy 35-year-old Japanese man presented to National Center for Global Health and Medicine in Tokyo with a two-day history of daily fever, mild headaches and mild arthralgia. Malaria parasites were found in the Giemsa-stained thin blood smear, which showed band forms similar to Plasmodium malariae. Although a nested PCR showed the amplification of the primer of Plasmodium vivax and Plasmodium knowlesi, he was finally diagnosed with P. knowlesi mono-infection by DNA sequencing. He was treated with mefloquine, and recovered without any complications. DNA sequencing of the PCR products is indispensable to confirm P. knowlesi infection, however there is limited access to DNA sequencing procedures in endemic areas. The extent of P. knowlesi transmission in Asia has not been clearly defined. There is limited availability of diagnostic tests and routine surveillance system for reporting an accurate diagnosis in the Asian endemic regions. Thus, reporting accurately diagnosed cases of P. knowlesi infection in travellers would be important for assessing the true nature of this emerging human infection.
authors.affiliation: Disease Control and Prevention Center, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan. k_taro023@yahoo.co.jp
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Tanizaki
authors.forename: Mugen
authors.initials: M
authors.lastname: Ujiie
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kato
authors.forename: Moritoshi
authors.initials: M
authors.lastname: Iwagami
authors.forename: Aki
authors.initials: A
authors.lastname: Hashimoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kutsuna
authors.forename: Nozomi
authors.initials: N
authors.lastname: Takeshita
authors.forename: Kyoko
authors.initials: K
authors.lastname: Hayakawa
authors.forename: Shuzo
authors.initials: S
authors.lastname: Kanagawa
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kano
authors.forename: Norio
authors.initials: N
authors.lastname: Ohmagari
mesh_terms: D000328:Adult; D000962:Antimalarials / Q000008:administration & dosage; D044466:Asian People; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D006801:Humans; D008288:Malaria / Q000175:diagnosis* / Q000469:parasitology / Q000473:pathology*; D008296:Malaysia; D008297:Male; D015767:Mefloquine / Q000008:administration & dosage; D016790:Plasmodium knowlesi / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014041:Tokyo; D014195:Travel; D016896:Treatment Outcome
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D015767:Mefloquine