Meisner Julianne, Curtis Kellie, Graham Thomas W, Apamaku Michael B, Manhart Lisa E, Rabinowitz Peter M
Department of Epidemiology, University of Washington, Seattle, Washington.
Center for One Health Research, University of Washington, Seattle, Washington.
Zoonoses Public Health. 2019 Feb;66(1):73-82. doi: 10.1111/zph.12530. Epub 2018 Nov 25.
Tuberculosis (TB) is a leading infectious cause of human death worldwide. In cattle, TB infection results in productivity losses, trade barriers and zoonotic transmission via milk, meat or direct contact. We conducted a cross-sectional study in rural communities in Uganda between 2014 and 2016 to evaluate the association between tuberculosis skin test (TST) positivity in humans and cattle-associated risk factors: household herd positivity and raw milk consumption. Human and cattle TSTs were performed in communities followed by a survey of household practices. TST data were available on 493 humans, 184 (37.3%) with positive results, and 1,441 cattle, 50 (3.5%) with positive results. We fit separate log binomial generalized estimating equation models for the herd positivity-human TST positivity association, stratified on sex; and for the raw milk consumption-human TST positivity association, stratified on frequency of milk consumption. Having at least one TST-positive bovid in the household's herd was significantly associated with lower risk of TB among men (prevalence ratio [PR] 0.66, 95% CI 0.49, 0.87) but was not significantly associated with TB among women (PR 1.21, 95% CI 0.76, 1.95). This apparent protective effect was contrary to our a priori hypothesis of higher exposure effect among men, the primary caretakers of cattle. This finding may be the result of residual confounding by socioeconomic status; wealthier individuals may be less likely to be TB positive, but more likely to have TST-positive herds by virtue of larger herd sizes, ability to purchase new and possibly infected stock, and propensity to keep more TB-susceptible European breeds. For raw milk consumption, effect estimates were close to one and not statistically significant. Thus, in settings where bovine TB prevalence is low, such as Uganda, cattle-associated zoonotic transmission may be rare, and cattle-associated risk factors may not be important drivers of human TB burden.
结核病(TB)是全球人类死亡的主要传染性病因。在牛群中,结核病感染会导致生产力损失、贸易壁垒以及通过牛奶、肉类或直接接触造成人畜共患病传播。2014年至2016年期间,我们在乌干达农村社区开展了一项横断面研究,以评估人类结核菌素皮肤试验(TST)阳性与牛相关危险因素(家庭畜群阳性和生奶消费)之间的关联。在社区中对人和牛进行了TST检测,随后对家庭行为进行了调查。有493人的TST数据,其中184人(37.3%)结果为阳性;有1441头牛的TST数据,其中50头(3.5%)结果为阳性。我们针对畜群阳性与人类TST阳性关联,按性别分层,拟合了单独的对数二项式广义估计方程模型;针对生奶消费与人类TST阳性关联,按牛奶消费频率分层,拟合了单独的对数二项式广义估计方程模型。家庭畜群中至少有一头TST阳性牛与男性结核病风险较低显著相关(患病率比[PR]0.66,95%置信区间0.49,0.87),但与女性结核病无显著关联(PR 1.21,95%置信区间0.76,1.95)。这种明显的保护作用与我们的先验假设相反,即男性作为牛的主要照料者,接触影响更大。这一发现可能是社会经济地位残余混杂的结果;较富裕的个体结核病呈阳性的可能性较小,但由于畜群规模较大、有能力购买新的且可能受感染的牲畜以及倾向于饲养更多易感染结核病的欧洲品种,他们拥有TST阳性畜群的可能性更大。对于生奶消费,效应估计值接近1,且无统计学意义。因此,在牛结核病患病率较低的地区,如乌干达,牛相关的人畜共患病传播可能很少见,且牛相关危险因素可能不是人类结核病负担的重要驱动因素。