Multiple Virus Lineages Sharing Recent Common Ancestry Were Associated with a Large Rift Valley Fever Outbreak among Livestock in Kenya during 2006-2007
Multiple Virus Lineages Sharing Recent Common Ancestry Were Associated with a Large Rift Valley Fever Outbreak among Livestock in Kenya during 2006-2007
复制标题
DOI：
10.1128/jvi.01519-08
复制
发表时间：
2008-11-15
影响因子：
5.4
通讯作者：
Nichol, Stuart T.
中科院分区：
文献类型：
--
作者：
Bird, Brian H.;Githinji, Jane W. K.;Nichol, Stuart T.
裂谷热(RVF)病毒历来在非洲、马达加斯加和阿拉伯半岛引起广泛和广泛的严重人畜疾病暴发。继2006年深秋异常强降雨之后，肯尼亚东北部加里萨区和索马里南部的半干旱地区出现了与裂谷热病毒感染相一致的人和动物疾病报告。在初步确认裂谷热病毒实验室后，在肯尼亚卡贝特的肯尼亚中央兽医实验室建立了一个高通量裂谷热诊断设施，以支持对受感染牲畜的实时识别，并促进疫情应对和控制活动。总共从肯尼亚71个行政区的55个行政区收集了来自各种动物物种的3250个标本，包括驯养牲畜(牛、绵羊、山羊和骆驼)和野生动物，对它们进行了分子和血清学分析。在肯尼亚23个区的9.2%接受检测的动物中发现了裂谷热感染的证据，这反映了受影响牲畜的数量和暴发的地理范围。S、M和/或L基因组片段的完整序列是从31份裂谷热病毒样本中获得的，这些样本跨越了整个已知暴发期(12-5月)和受裂谷热病毒活动影响的地理区域。广泛的基因组分析表明，2006/2007年暴发的病毒与1997-1998年东非裂谷热暴发的病毒同时传播，基因片段重新组合，以及共同的祖先。还有证据表明，在2006-2007年暴发前2至4年，基因组多样性和有效种群规模最近有所增加，这表明裂谷热病毒在疫病间/流行期间正在进行活动和进化。这些发现对进一步研究裂谷热病毒的基本生态和设计未来的监测/诊断活动具有重要意义，并突出表明迫切需要安全有效的疫苗和抗病毒化合物来对抗这一重大的兽医和公共卫生威胁。
Rift Valley fever (RVF) virus historically has caused widespread and extensive outbreaks of severe human and livestock disease throughout Africa, Madagascar, and the Arabian Peninsula. Following unusually heavy rainfall during the late autumn of 2006, reports of human and animal illness consistent with RVF virus infection emerged across semiarid regions of the Garissa District of northeastern Kenya and southern Somalia. Following initial RVF virus laboratory confirmation, a high-throughput RVF diagnostic facility was established at the Kenyan Central Veterinary Laboratories in Kabete, Kenya, to support the real-time identification of infected livestock and to facilitate outbreak response and control activities. A total of 3,250 specimens from a variety of animal species, including domesticated livestock (cattle, sheep, goats, and camels) and wildlife collected from a total of 55 of 71 Kenyan administrative districts, were tested by molecular and serologic assays. Evidence of RVF infection was found in 9.2% of animals tested and across 23 districts of Kenya, reflecting the large number of affected livestock and the geographic extent of the outbreak. The complete S, M, and/or L genome segment sequence was obtained from a total of 31 RVF virus specimens spanning the entire known outbreak period (December-May) and geographic areas affected by RVF virus activity. Extensive genomic analyses demonstrated the concurrent circulation of multiple virus lineages, gene segment reassortment, and the common ancestry of the 2006/2007 outbreak viruses with those from the 1997-1998 east African RVF outbreak. Evidence of recent increases in genomic diversity and effective population size 2 to 4 years prior to the 2006-2007 outbreak also was found, indicating ongoing RVF virus activity and evolution during the interepizootic/epidemic period. These findings have implications for further studies of basic RVF virus ecology and the design of future surveillance/diagnostic activities, and they highlight the critical need for safe and effective vaccines and antiviral compounds to combat this significant veterinary and public health threat.