急性A型肝炎自2015年開始於男男性行為族群的群聚感染

Outbreak of Acute Hepatitis A Infection in Men Who Had Sex with Men in Taiwan Since 2015

A型肝炎在台灣於近數十年低發生率的法定傳染病，相對大部分年輕人缺乏A型肝炎保護抗體。自2015年下半年開始，台灣北部醫療機構陸續發現因為急性A型肝炎而住院或就醫的個案，其中有許多是Human Immunodeficiency Virus（HIV）感染的個案。2016年急性A型肝炎通報個案數全年持續升高。疾病管制署為控制急性A型肝炎的蔓延自2016年10月開始推廣A型肝炎抗體陰性的HIV的個案年齡小於40歲（1977年出生）可以免費接種一劑A型肝炎疫苗的措施，自2017年3月1日擴大施打對象至A型肝炎抗體陰性的HIV的個案，期望更快提升具有保護抗體的人口數，降低男男性行為族群再發生急性A型肝炎群聚感染與減少擴散到其他年齡與族群的風險。

Acute hepatitis A infection and outbreak among men who had sex with men (MSM) was reported in several countries in the past years. In Taiwan, acute hepatitis A infection has been rare in the recent decades. However, an unusual increase in the number of cases of acute hepatitis A infection has been observed since the third quarter of 2015, which persisted through 2016. Majority of the reported cases of acute hepatitis A infection occurred in patients with chronic human immunodeficiency virus (HIV) infection, most of whom were MSM. The newly acute hepatitis A infection cases decreased after the implementation of the hepatitis A virus (HAV) vaccination program, which was supported by the Center of Disease Control (CDC), Taiwan since October 2016. Since March 1, 2017, the enrolment criteria for the HAV vaccination program were extended to all HIV-positive patients who tested negative for anti-HAV IgG antibody.