Wardrop Nicola A, Thomas Lian F, Cook Elizabeth A J, de Glanville William A, Atkinson Peter M, Wamae Claire N, Fèvre Eric M
Geography and Environment, University of Southampton, Southampton, United Kingdom.
Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom.
PLoS Negl Trop Dis. 2016 Oct 7;10(10):e0005032. doi: 10.1371/journal.pntd.0005032. eCollection 2016 Oct.
Evidence suggests that the intracellular bacterial pathogen Coxiella burnetii (which causes Q fever) is widespread, with a near global distribution. While there has been increasing attention to Q fever epidemiology in high-income settings, a recent systematic review highlighted significant gaps in our understanding of the prevalence, spatial distribution and risk factors for Q fever infection across Africa. This research aimed to provide a One Health assessment of Q fever epidemiology in parts of Western and Nyanza Provinces, Western Kenya, in cattle and humans. A cross-sectional survey was conducted: serum samples from 2049 humans and 955 cattle in 416 homesteads were analysed for C. burnetii antibodies. Questionnaires covering demographic, socio-economic and husbandry information were also administered. These data were linked to environmental datasets based on geographical locations (e.g., land cover). Correlation and spatial-cross correlation analyses were applied to assess the potential link between cattle and human seroprevalence. Multilevel regression analysis was used to assess the relationships between a range of socio-economic, demographic and environmental factors and sero-positivity in both humans and animals. The overall sero-prevalence of C. burnetii was 2.5% in humans and 10.5% in cattle, but we found no evidence of correlation between cattle and human seroprevalence either within households, or when incorporating spatial proximity to other households in the survey. Multilevel modelling indicated the importance of several factors for exposure to the organism. Cattle obtained from market (as opposed to those bred in their homestead) and those residing in areas with lower precipitation levels had the highest sero-prevalence. For humans, the youngest age group had the highest odds of seropositivity, variations were observed between ethnic groups, and frequent livestock contact (specifically grazing and dealing with abortion material) was also a risk factor. These results illustrate endemicity of C. burnetii in western Kenya, although prevalence is relatively low. The analysis indicates that while environmental factors may play a role in cattle exposure patterns, human exposure patterns are likely to be driven more strongly by livestock contacts. The implication of livestock markets in cattle exposure risks suggests these may be a suitable target for interventions.
有证据表明，细胞内细菌病原体伯氏考克斯体（可引起Q热）分布广泛，几乎遍布全球。虽然高收入地区对Q热流行病学的关注日益增加，但最近的一项系统综述强调，我们对非洲Q热感染的患病率、空间分布和风险因素的了解存在重大差距。本研究旨在对肯尼亚西部的西省和尼扬扎省部分地区的牛和人类的Q热流行病学进行“同一健康”评估。开展了一项横断面调查：对416个家庭中2049名人类和955头牛的血清样本进行了伯氏考克斯体抗体分析。还发放了涵盖人口、社会经济和养殖信息的问卷。这些数据与基于地理位置（如土地覆盖）的环境数据集相关联。应用相关性和空间交叉相关性分析来评估牛和人类血清阳性率之间的潜在联系。采用多水平回归分析来评估一系列社会经济、人口和环境因素与人类和动物血清阳性之间的关系。伯氏考克斯体的总体血清阳性率在人类中为2.5%，在牛中为10.5%，但我们没有发现家庭内部或在调查中纳入与其他家庭的空间接近度时，牛和人类血清阳性率之间存在相关性的证据。多水平建模表明了几个因素对接触该病原体的重要性。从市场购买的牛（与在自家养殖的牛相对）以及生活在降水量较低地区的牛血清阳性率最高。对于人类，最年轻的年龄组血清阳性几率最高，不同种族之间存在差异，频繁接触牲畜（特别是放牧和处理流产材料）也是一个风险因素。这些结果表明伯氏考克斯体在肯尼亚西部呈地方性流行，尽管患病率相对较低。分析表明，虽然环境因素可能在牛的接触模式中起作用，但人类的接触模式可能更多地受到与牲畜接触的驱动。牲畜市场在牛的接触风险中的影响表明，这些可能是合适的干预目标。
