Tropical Medicine and Health  2015;43(2):85-88

doi:10.2149/tmh.2014-34

Dengue Hemorrhagic Fever in a Japanese Traveler with Pre-existing Japanese Encephalitis Virus Antibody

Rumi Sato ; Nobuyuki Hamada ; Takahito Kashiwagi ; Yoshihiro Imamura ; Koyu Hara ; Munetsugu Nishimura ; Tomoko Kamimura ; Tomohiko Takasaki ; Hiroshi Watanabe ; Takeharu Koga

Keywords

dengue hemorrhagic fever; Japanese encephalitis virus antibody; cross-reactive antibody; imported infection; petechiae; thrombocytopenia; antibody-dependent enhancement (ADE)

Country

Japan

Language

English

Abstract

An adult Japanese man who had just returned from Thailand developed dengue hemorrhagic fever (DHF). A primary infection of dengue virus (DENV) was confirmed, specifically DENV serotype 2 (DENV-2), on the basis of the detection of the virus genome, a significant increase in the neutralizing antibody and the isolation of DENV-2. DHF is often observed following a secondary infection from another serotype of dengue virus, particularly in children, but this case was a primary infection of DENV. Japan is a non-endemic country for dengue disease. In fact, only Japanese encephalitis (JE) is known to be a member of the endemic flavivirus family. In this study, IgG antibody against Japanese encephalitis virus (JEV) was detected. JEV belongs to the family of dengue virus and prevails in Japan, particularly Kyushu. Among many risk factors for the occurrence of DHF, a plausible candidate could be a cross-reactive antibody-dependent enhancement (ADE) mechanism caused by JEV antibody. This indicates that most Japanese travelers who living in dengue non-endemic areas, particularly Kyushu, should be aware of the occurrence of DHF.