1 Department of Public Health, Pharmacology and Toxicology, University of Nairobi , Nairobi, Kenya .
2 Department of Biomedical Sciences, Colorado State University , Fort Collins, Colorado.
Vector Borne Zoonotic Dis. 2017 Feb;17(2):141-146. doi: 10.1089/vbz.2016.1988. Epub 2016 Dec 8.
Rift Valley fever (RVF) is a vector-borne zoonotic disease caused by phlebovirus in the family Bunyaviridae. In Kenya, major outbreaks occurred in 1997-1998 and 2006-2007 leading to human deaths, huge economic losses because of livestock morbidity, mortality, and restrictions on livestock trade.
This study was conducted to determine RVF seroprevalence in cattle, sheep, and goats during an interepidemic period in Garissa County in Kenya.
In July 2013, we performed a cross-sectional survey and sampled 370 ruminants from eight RVF-prone areas of Garissa County. Rift Valley fever virus (RVFV) antibodies were detected using a multispecies competitive enzyme-linked immunosorbent assay. Mixed effect logistic regression models were used to determine the association between RVF seropositivity and species, sex, age, and location of the animals.
A total of 271 goats, 87 sheep, and 12 cattle were sampled and the overall immunoglobulin G seroprevalence was 27.6% (95% CI [23-32.1]). Sheep, cattle, and goats had seroprevalences of 32.2% (95% CI [20.6-31]), 33.3% (95% CI [6.7-60]), and 25.8% (95% CI [22.4-42]), respectively. Seropositivity in males was 31.8% (95% CI [22.2-31.8]), whereas that of females was 27% (95% CI [18.1-45.6]).
The high seroprevalence suggests RVFV circulation in domestic ruminants in Garissa and may be indicative of a subclinal infection. These findings provide evidence of RVF disease status that will assist decision-makers to flag areas of high risk of RVF outbreaks and prioritize the implementation of timely and cost-effective vaccination programs.
裂谷热（RVF）是一种由布尼亚病毒科的披膜病毒引起的虫媒动物源性传染病。在肯尼亚，1997-1998 年和 2006-2007 年发生了两次重大疫情，导致人类死亡，牲畜发病率、死亡率高，以及牲畜贸易受限，造成了巨大的经济损失。
本研究旨在确定肯尼亚加里萨县在裂谷热流行间歇期牛、绵羊和山羊中的 RVF 血清流行率。
2013 年 7 月，我们进行了一项横断面调查，从加里萨县 8 个裂谷热高危地区采集了 370 只反刍动物。使用多物种竞争酶联免疫吸附试验检测裂谷热病毒（RVFV）抗体。采用混合效应逻辑回归模型来确定 RVF 血清阳性率与动物的物种、性别、年龄和地点之间的关系。
共采集了 271 只山羊、87 只绵羊和 12 头牛，总免疫球蛋白 G 血清阳性率为 27.6%（95%CI[23-32.1]）。绵羊、牛和山羊的血清阳性率分别为 32.2%（95%CI[20.6-31]）、33.3%（95%CI[6.7-60]）和 25.8%（95%CI[22.4-42]）。雄性的血清阳性率为 31.8%（95%CI[22.2-31.8]），而雌性的血清阳性率为 27%（95%CI[18.1-45.6]）。
高血清阳性率表明 RVFV 在加里萨县的家养反刍动物中循环，可能表明存在亚临床感染。这些发现为裂谷热疾病状况提供了证据，将有助于决策者确定裂谷热爆发的高风险地区，并优先实施及时和具有成本效益的疫苗接种计划。
