Overview of Zika virus (ZIKV) infection in regards to the Brazilian epidemic

Zika virus (ZIKV), a mosquito-borne flavivirus, belongs to the Flaviviridae family, genus Flavivirus. ZIKV was initially isolated in 1947 from a sentinel monkey in the Zika forest, Uganda. Little clinical importance was attributed to ZIKV, once only few symptomatic cases were reported in some African and Southeast Asiatic countries. This situation changed in 2007, when a large outbreak was registered on the Yap Island, Micronesia, caused by the Asian ZIKV lineage. Between 2013 and 2014, ZIKV spread explosively and caused many outbreaks in different islands of the Southern Pacific Ocean and in 2015 autochthonous transmission was reported in Brazil. Currently, Brazil is the country with the highest number of ZIKV-positive cases in Latin America. Moreover, for the first time after the discovery of ZIKV, the Brazilian scientists are studying the possibility for the virus to cause severe congenital infection related to microcephaly and serious birth defects due to the time-spatial coincidence of the alarming increase of newborns with microcephaly and the Brazilian ZIKV epidemic. The present review summarizes recent information for ZIKV epidemiology, clinical picture, transmission, diagnosis and the consequences of this emerging virus in Brazil.

寨卡病毒（Zika virus, ZIKV）是一种经蚊媒传播的黄病毒，隶属于黄病毒科（Flaviviridae）黄病毒属（Flavivirus）。1947年，研究人员首次从乌干达寨卡森林的一只哨兵猴体内分离出寨卡病毒。此前寨卡病毒并未受到足够的临床重视，仅在部分非洲及东南亚国家有少量症状病例报告。2007年，这一局面被彻底改变：密克罗尼西亚雅浦岛暴发了大规模寨卡病毒疫情，此次疫情由亚洲型寨卡病毒谱系引发。2013至2014年间，寨卡病毒呈爆发式扩散，在南太平洋诸多岛屿引发多起疫情；2015年，巴西首次报告了本土传播（autochthonous transmission）病例。目前，巴西是拉丁美洲寨卡病毒检测阳性病例数最多的国家。尤为值得关注的是，寨卡病毒被发现以来首次出现与重症先天性感染相关的疑似情形——巴西科学家正研究该病毒是否会引发小头畸形（microcephaly）及严重出生缺陷，这一推测源于新生儿小头畸形病例的激增与巴西寨卡病毒疫情在时间与空间上的高度重合。本综述总结了当前关于寨卡病毒的流行病学、临床表现、传播途径、诊断方法，以及该新兴病毒在巴西引发的一系列后果的最新研究进展。