エンテロウイルスによる手足口病と脳炎，髄膜炎

Hand-Foot-and-Mouth Disease, Aseptic Meningitis, and Encephalitis Caused by Enterovirus

エンテロウイルスA71型（EV-A71），コクサッキーウイルスA群16型（CV-A16）および近年はCV-A6が手足口病の主要な起因病原体である。これらはすべてピコルナウイルス科，エンテロウイルス属，Enterovirus A種に属し，時に無菌性髄膜炎および脳炎および麻痺を引き起こす。東アジア，東南アジアは1997〜2013年に大きなEV-A71のアウトブレイクを経験し，その間に致死例を含む重篤な脳炎症例を経験した。本論文では手足口病に関連した，中枢神経系感染症，疫学，臨床症状および治療，および手足口病研究の歴史をまとめた。重症EV-A71感染症の予防，重症度分類，診断，検体採取法，および治療に関して概説した。

Abstract

Enterovirus A71 (EV-A71), coxsackievirus A16 (CV-A16), and CV-A6 are the major causative agents of Hand-foot-and-mouth disease (HFMD). These viruses belong to the species Enterovirus A of the genus Enterovirus of the family Picornaviridae. These viruses can also cause aseptic meningitis (AM), encephalitis and/or paralysis. EV-A71 is one of the main infectious agents related to severe encephalitis. Between 1997 and 2013, East and Southeast Asia experienced large encephalitis outbreaks caused by EV-A71 infections, which ranged from severe to lethal. In Japan, national surveillance for HFMD has been conducted since 1982 by monitoring both the notifications of HFMD patients and the causative agents. Even though EV-A71 and CV-A16 are the two major causative agents of HFMD, CV-A6 has been reported to cause atypical HFMD in Japan, since 2011. Both CV-A6 and CV-A16 also cause encephalitis: however, the reported numbers of encephalitis caused by CV-A6 and CV-A16 have been far fewer than those caused by EV-A71. Vaccines against EV-A71 have become available in some Asian countries, such as in China, but as of 2017 they remain unavailable in Japan, likely due to the sparsity of fatal cases. This article summarizes the complications of HFMD on the central nervous system, as well as its epidemiology, clinical manifestations, and treatment. Moreover, the article reviews the history of HFMD and discusses the experimental results of research aimed at the prevention, grading, sample collection, diagnosis, and treatment of severe EV-A71 infections.