Brucellosis Seroprevalence in Humans and Risk Factors Among High-Risk Groups at Two Urban Populations in Kenya

Brucellosis is a zoonotic bacterial disease that can affect humans and animals. It is often transmitted to humans through the consumption of contaminated animal products or by direct contact with infected animals. In Kenya, data on human and animal brucellosis are limited.

To investigate the seroprevalence and molecular prevalence of human brucellosis in Kenya, we randomly selected from the healthy participants with possible exposure to animals and animal products and randomly selected 348 out of 2,779 human blood samples, that were obtained from a larger longitudinal cohort study that investigated of dengue, chikungunya and Rift Valley Disease exposure in western (Kisumu) and coastal (Ukunda) Kenya.

Our study included 126 males (36%), 222 females (64%) in different age categories, and 61 children aged 16 years and younger (18%), with an overall median age of 29.5 years (2- to 75-year age range). Samples were tested by Abnova Brucella IgG enzyme-linked immunosorbent assay (ELISA) Kit (KA0954). Of the tested individuals, anti-Brucella IgG antibodies were detected in 96 (28%) of 348 randomly selected participants. All samples yielded negative results in quantitative polymerase chain reaction (qPCR) analysis. There was no statistically significant correlation between Brucella exposure and study site, gender, age, socioeconomic status, ownership of particular livestock (sheep, goats, and cattle), or consumption of raw animal products. However, highly educated individuals were more likely to have Brucella exposure (odds ratio = 2.02, 1.20-3.41, p = 0.01).

In comparison to previous seroprevalence-based studies conducted in nonpastoral Kenyan communities, our study revealed relatively higher seropositivity. This article emphasizes the importance of conducting surveillance for brucellosis in urban areas. Urban brucellosis surveillance within the framework of One Health could serve as a baseline to guide future research on brucellosis in humans.