Positive association between Brucella spp. seroprevalences in livestock and humans from a cross-sectional study in Garissa and Tana River Counties, Kenya
Positive association between Brucella spp. seroprevalences in livestock and humans from a cross-sectional study in Garissa and Tana River Counties, Kenya
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DOI：
10.1371/journal.pntd.0007506
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发表时间：
2019-10-01
影响因子：
3.8
通讯作者：
Bett, Bernard
中科院分区：
文献类型：
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作者：
Kairu-Wanyoike, Salome;Nyamwaya, Doris;Bett, Bernard
c背景布鲁氏菌属是一种具有高度公共卫生和社会经济重要性的人畜共患细菌剂。它会感染包括野生动物在内的多种动物，人们可能会通过直接接触受感染的动物或食用生的或未煮熟的动物产品而接触到它。设计了一项牲畜-人类横断面研究，以确定牲畜和人类布鲁氏菌病的血清阳性率和危险因素。估计集群内相关系数（ICC），这些意见在家庭和村庄level.MethodologyThe研究在加里萨（特别是Ijara和Sangailu地区）和塔纳河（布拉和霍拉）县。以家庭为分析单位，采用标准程序得出样本量。血清样本从选定的牲畜和人从随机选择的家庭。在这两个县都对人类进行了采样，而牲畜只能在塔纳河县进行采样。使用ELISA试剂盒筛选获得的样品的抗布鲁氏菌IgG抗体。数据进行了分析，采用广义线性混合效应Logistic回归模型与家庭（牛群）和村庄被用作随机效应。在家畜和人中的血清阳性率分别为3.47%（95%置信区间[CI]：2.72 - 4.36%）和35.81%（95% CI：32.87 - 38.84）。在牲畜中，年龄较大的动物和在Hola采样的动物的血清阳性率明显高于年龄较小的动物或在Bura采样的动物。牛群和村庄的随机效应是显着的，与这些变量相关的ICC估计值分别为0.40（95%CI：0.22 - 0.60）和0.24（95%CI：0.08 - 0.52）。在人类中，布鲁氏菌属（Brucella spp.）老年人、男性和居住在牧区的人血清阳性率明显高于年轻人、女性或居住在灌溉或河流地区的人。来自至少有一只血清反应阳性动物的家庭的人与那些没有血清反应阳性动物的人相比，血清反应阳性的可能性高3.35倍（95% CI：1.51 - 7.41）。人类暴露显著聚集在家庭层面; ICC估计值为0.21（95%CI：0.06 - 0.52）。血清阳性动物在一个家庭显着增加的几率布鲁氏菌属。血清反应阳性的人。暴露于布鲁氏菌属牲畜和人类的死亡率在家庭一级显著集中。这表明，根据报告的主要病例（无论是人还是牲畜）的地点，基于风险的监测措施可用于检测布鲁氏菌。分别感染牲畜或人类。
c BackgroundBrucella spp. is a zoonotic bacterial agent of high public health and socio-economic importance. It infects many species of animals including wildlife, and people may get exposed through direct contact with an infected animal or consumption of raw or undercooked animal products. A linked livestock-human cross-sectional study to determine seroprevalences and risk factors of brucellosis in livestock and humans was designed. Estimates were made for intra-cluster correlation coefficients (ICCs) for these observations at the household and village levels.MethodologyThe study was implemented in Garissa (specifically Ijara and Sangailu areas) and Tana River (Bura and Hola) counties. A household was the unit of analysis and the sample size was derived using the standard procedures. Serum samples were obtained from selected livestock and people from randomly selected households. Humans were sampled in both counties, while livestock could be sampled only in Tana River County. Samples obtained were screened for anti-Brucella IgG antibodies using ELISA kits. Data were analyzed using generalized linear mixed effects logistic regression models with the household (herd) and village being used as random effects.ResultsThe overall Brucella spp. seroprevalences were 3.47% (95% confidence interval [CI]: 2.72-4.36%) and 35.81% (95% CI: 32.87-38.84) in livestock and humans, respectively. In livestock, older animals and those sampled in Hola had significantly higher seroprevalences than younger ones or those sampled in Bura. Herd and village random effects were significant and ICC estimates associated with these variables were 0.40 (95% CI: 0.22-0.60) and 0.24 (95% CI: 0.08-0.52), respectively. In humans, Brucella spp. seroprevalence was significantly higher in older people, males, and people who lived in pastoral areas than younger ones, females or those who lived in irrigated or riverine areas. People from households that had at least one seropositive animal were 3.35 (95% CI: 1.51-7.41) times more likely to be seropositive compared to those that did not. Human exposures significantly clustered at the household level; the ICC estimate obtained was 0.21 (95% CI: 0.06-0.52).ConclusionThe presence of a Brucella spp.-seropositive animal in a household significantly increased the odds of Brucella spp. seropositivity in humans in that household. Exposure to Brucella spp. of both livestock and humans clustered significantly at the household level. This suggests that risk-based surveillance measures, guided by locations of primary cases reported, either in humans or livestock, can be used to detect Brucella spp. infections in livestock or humans, respectively.