Original data.

Brucellosis, Rift Valley fever (RVF) and Q fever are zoonoses prevalent in many developing countries, causing a high burden on human and animal health. Only a few studies are available on these among agro-pastoralist communities and their livestock in Chad. The objective of our study was to estimate brucellosis, RVF and Q fever seroprevalence among Chadian agro-pastoralist communities and their livestock, and to investigate risk factors for seropositivity. We conducted a multi-stage cross-sectional serological survey in two rural health districts, Yao and Danamadji (966 human and 1041 livestock (cattle, sheep, goat and equine) samples)). The true seroprevalence were calculated applying a Bayesian framework to adjust for imperfect diagnostic test characteristics and accounting for clustering in the study design. Risk factors for each of the zoonotic diseases were estimated using mixed effects logistic regression models. The overall prevalence for brucellosis, Q fever and RVF combined for both regions was estimated at 0.2% [95% credibility Interval: 0–1.1], 49.1% [%CI: 38.9–58.8] and 28.1% [%CI: 23.4–33.3] in humans, and 0.3% [%CI: 0–1.5], 12.8% [%CI: 9.7–16.4] and 10.2% [%CI: 7.6–13.4] in animals. Risk factors correlating significantly with the respective disease seropositivity were sex for human brucellosis, sex and Q fever co-infection for animal brucellosis, age for human Q fever, species and brucellosis co-infection for animal Q fever, age and herd-level animal RVF seroprevalence within the same cluster for human RVF, and cluster-level human RVF seroprevalence within the same cluster for animal RVF. In Danamadji and Yao, Q fever and RVF are notably seroprevalent among agro-pastoralist human and animal communities, while brucellosis appears to have a low prevalence. Correlation between the seroprevalence between humans and animals living in the same communities was detected for RVF, highlighting the interlinkage of human and animal transmissible diseases and of their health, highlighting the importance of a One Health approach.

布鲁氏菌病（Brucellosis）、裂谷热（Rift Valley fever, RVF）与Q热（Q fever）均为在众多发展中国家流行的人畜共患病，给人类与动物健康造成沉重负担。目前针对乍得农牧社区及其家畜的此类疾病研究较为匮乏。本研究旨在估算乍得农牧社区及其家畜中布鲁氏菌病、裂谷热与Q热的血清阳性率，并探究血清阳性的相关危险因素。我们在乍得的两个农村卫生区——雅奥（Yao）与达纳马吉（Danamadji）开展了多阶段横断面血清学调查，共采集966份人类样本与1041份家畜样本，样本涵盖牛、绵羊、山羊及马四类动物。研究采用贝叶斯框架（Bayesian framework）计算真实血清阳性率，以校正诊断试验特性不完善的问题，并纳入研究设计中的聚类效应进行分析。针对每种人畜共患病的危险因素，我们采用混合效应logistic回归模型（mixed effects logistic regression models）进行估算。两个地区的人类人群中，布鲁氏菌病、Q热与裂谷热的总体血清阳性率分别为0.2%[95%可信区间（credibility interval）：0~1.1]、49.1%[95%可信区间：38.9~58.8]与28.1%[95%可信区间：23.4~33.3]；家畜人群中则分别为0.3%[95%可信区间：0~1.5]、12.8%[95%可信区间：9.7~16.4]与10.2%[95%可信区间：7.6~13.4]。与各疾病血清阳性显著相关的危险因素包括：人类布鲁氏菌病的性别因素、家畜布鲁氏菌病的性别与Q热合并感染因素、人类Q热的年龄因素、家畜Q热的物种与布鲁氏菌病合并感染因素、人类裂谷热的年龄与同聚类内家畜群裂谷热血清阳性率因素，以及家畜裂谷热的同聚类内人群裂谷热血清阳性率因素。在达纳马吉与雅奥地区，Q热与裂谷热在农牧社区的人类与家畜群体中血清阳性率显著较高，而布鲁氏菌病的流行率较低。本研究检测到同社区内人类与动物的裂谷热血清阳性率存在相关性，凸显了人类与动物传染病及其健康的内在关联，也印证了一体化健康（One Health）策略的重要性。