Institute for Human Infections and Immunity, Center for Tropical Diseases, Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA.
PLoS Negl Trop Dis. 2012;6(2):e1477. doi: 10.1371/journal.pntd.0001477. Epub 2012 Feb 28.
Zika virus (ZIKV) is a mosquito-borne flavivirus distributed throughout much of Africa and Asia. Infection with the virus may cause acute febrile illness that clinically resembles dengue fever. A recent study indicated the existence of three geographically distinct viral lineages; however this analysis utilized only a single viral gene. Although ZIKV has been known to circulate in both Africa and Asia since at least the 1950s, little is known about the genetic relationships between geographically distinct virus strains. Moreover, the geographic origin of the strains responsible for the epidemic that occurred on Yap Island, Federated States of Micronesia in 2007, and a 2010 pediatric case in Cambodia, has not been determined.
METHODOLOGY/PRINCIPAL FINDINGS: To elucidate the genetic relationships of geographically distinct ZIKV strains and the origin of the strains responsible for the 2007 outbreak on Yap Island and a 2010 Cambodian pediatric case of ZIKV infection, the nucleotide sequences of the open reading frame of five isolates from Cambodia, Malaysia, Nigeria, Uganda, and Senegal collected between 1947 and 2010 were determined. Phylogenetic analyses of these and previously published ZIKV sequences revealed the existence of two main virus lineages (African and Asian) and that the strain responsible for the Yap epidemic and the Cambodian case most likely originated in Southeast Asia. Examination of the nucleotide and amino acid sequence alignments revealed the loss of a potential glycosylation site in some of the virus strains, which may correlate with the passage history of the virus.
CONCLUSIONS/SIGNIFICANCE: The basal position of the ZIKV strain isolated in Malaysia in 1966 suggests that the recent outbreak in Micronesia was initiated by a strain from Southeast Asia. Because ZIKV infection in humans produces an illness clinically similar to dengue fever and many other tropical infectious diseases, it is likely greatly misdiagnosed and underreported.
Zika 病毒（ZIKV）是一种通过蚊子传播的黄病毒，分布在非洲和亚洲的大部分地区。感染该病毒可能会引起类似于登革热的急性发热疾病。最近的一项研究表明，存在三个在地理上有区别的病毒谱系；然而，该分析仅利用了单一的病毒基因。尽管自 20 世纪 50 年代以来，ZIKV 已在非洲和亚洲传播，但对于地理上不同的病毒株之间的遗传关系知之甚少。此外，造成 2007 年在密克罗尼西亚联邦雅浦岛爆发的疫情以及 2010 年柬埔寨一名儿科患者感染 ZIKV 的病毒株的地理起源尚未确定。
方法/主要发现：为了阐明地理上不同的 ZIKV 株的遗传关系以及造成 2007 年雅浦岛爆发疫情和 2010 年柬埔寨儿科 ZIKV 感染病例的病毒株的起源，我们测定了 1947 年至 2010 年间从柬埔寨、马来西亚、尼日利亚、乌干达和塞内加尔采集的五个分离株的开放阅读框的核苷酸序列。对这些序列和以前发表的 ZIKV 序列进行的系统发育分析表明，存在两个主要的病毒谱系（非洲和亚洲），而造成雅浦岛疫情和柬埔寨病例的病毒株很可能起源于东南亚。对核苷酸和氨基酸序列比对的检查表明，一些病毒株丢失了一个潜在的糖基化位点，这可能与病毒的传播史有关。
结论/意义：马来西亚 1966 年分离的 ZIKV 株的基础位置表明，最近在密克罗尼西亚的爆发是由来自东南亚的一个株系引发的。由于人类感染 ZIKV 会引起类似于登革热和许多其他热带传染病的疾病，因此很可能被大大误诊和漏报。
