Institute of Infection, Veterinary and Ecological Sciences (IVES), University of Liverpool, Liverpool, United Kingdom.
International Livestock Research Institute (ILRI), Nairobi, Kenya.
PLoS Negl Trop Dis. 2023 May 12;17(5):e0011295. doi: 10.1371/journal.pntd.0011295. eCollection 2023 May.
Despite recognition of histoplasmosis as a disease of national public health concern in Kenya, the burden of Histoplasma capsulatum in the general population remains unknown. This study examined the human seroprevalence of anti-Histoplasma antibody and explored associations between seropositivity and demographic and environmental variables, in Busia county, western Kenya.
Biobanked serum samples and associated data, from a previous cross-sectional survey, were examined. Latex agglutination tests to detect the presence of anti-Histoplasma antibody were performed on serum samples from 670 survey respondents, representing 178 households within 102 sub-locations. Potential epidemiologic risk factors for H. capsulatum exposure were explored using multi-level multivariable logistic regression analysis with household and sub-location included as random effects.
The apparent sample seroprevalence of anti-Histoplasma antibody was 15.5% (n = 104/670, 95% Confidence Interval (CI) 12.9-18.5%). A multivariable logistic regression model identified increased odds of H. capsulatum seropositivity in respondents reporting rats within the household within the previous 12 months (OR = 2.99 90% CI 1.04-8.55, p = 0.04). Compared to respondents aged 25-34 years, the odds of seropositivity were higher in respondents aged 15-24 years (OR = 2.70 90% CI 1.04-6.97, p = 0.04).
The seroprevalence result provides a baseline for sample size approximations for future epidemiologic studies of the burden of H. capsulatum exposure in Busia county. The final model explored theoretically plausible risk factors for H. capsulatum exposure in the region. A number of factors may contribute to the complex epidemiological picture impacting H. capsulatum exposure status at the human-animal-environment interface in western Kenya. Focussed H. capsulatum research is warranted to determine the contextual significance of identified associations, and in representative sample populations.
尽管肯尼亚已将组织胞浆菌病视为国家公共卫生关注的疾病，但人群中荚膜组织胞浆菌的负担仍不清楚。本研究在肯尼亚西部布西亚县检查了人类对荚膜组织胞浆菌抗体的血清流行率，并探讨了血清阳性与人口统计学和环境变量之间的关联。
对之前的横断面调查中的生物银行血清样本和相关数据进行了检查。对来自 670 名调查对象的血清样本进行乳胶凝集试验，以检测抗组织胞浆菌抗体的存在，这些样本代表了 102 个分区中的 178 个家庭。使用多层多变量逻辑回归分析，将家庭和分区作为随机效应，探讨了荚膜组织胞浆菌暴露的潜在流行病学危险因素。
明显的样本血清抗组织胞浆菌抗体流行率为 15.5%（n=104/670，95%置信区间（CI）12.9-18.5%）。多变量逻辑回归模型确定，在过去 12 个月内报告家庭内有老鼠的调查对象中，荚膜组织胞浆菌血清阳性的几率更高（OR=2.99 90%CI 1.04-8.55，p=0.04）。与 25-34 岁的调查对象相比，15-24 岁的调查对象的血清阳性率更高（OR=2.70 90%CI 1.04-6.97，p=0.04）。
血清流行率结果为今后在布西亚县进行荚膜组织胞浆菌暴露负担的流行病学研究提供了样本量近似值的基线。最终模型探讨了该地区荚膜组织胞浆菌暴露的理论上合理的危险因素。许多因素可能导致在肯尼亚西部的人类-动物-环境界面上影响荚膜组织胞浆菌暴露状况的复杂的流行病学情况。需要进行有针对性的荚膜组织胞浆菌研究，以确定确定关联的背景意义，并在代表性样本人群中进行研究。
