Zoonotic Pathogen Seroprevalence in Cattle in a Wildlife\u2013Livestock Interface, Kenya

Daniel Nthiwa,Silvia Alonso,David Odongo,Bernard Bett,Eucharia Kenya

doi:10.1007/s10393-019-01453-z

Abstract

A cross-sectional study was conducted to determine the seroprevalence of Brucella spp. and Leptospira spp. and risk factors of exposure in cattle in three zones with varying land use types and wildlife–livestock interactions. Five villages were selected purposively; two in areas with intensive livestock–wildlife interactions (zone 1), another two in areas with moderate livestock–wildlife interactions (zone 2) and one in areas where wildlife–livestock interactions are rarer (zone 3). Sera samples were collected from 1170 cattle belonging to 390 herds in all the zones and tested for antibodies against Brucella abortus and Leptospira interrogans serovar hardjo using ELISA kits. Data on putative risk factors for seropositivity of these pathogens in cattle were collected using a questionnaire. The overall apparent animal-level seroprevalence of brucellosis and leptospirosis was, respectively, 36.9% (95% CI 34.1–39.8) and 23.5% (95% CI 21.1–26.0). Brucella spp. seroprevalence was higher in zone 1 than in zones 2 and 3 (χ2 = 25.1, df = 2, P < 0.001). Zones 1 and 2 had significantly higher Leptospira spp. seroprevalence than zone 3 (χ2 = 7.0, df = 2, P = 0.029). Results of multivariable analyses identified animal sex (female) and zones (high interface area) as significant predictors (P < 0.05) of animal-level seropositivity of Brucella spp. For Leptospira spp., important predictors of animal-level seropositivity were animal sex (female), zones (moderate interface area) and herds utilizing a communal grazing reserve. The seroprevalences of Brucella spp. and Leptospira spp. in cattle were higher in areas with moderate to high wildlife–livestock interactions than those with rare interactions.

Highlights

Electronic supplementary material: The online version of this article contains supplementary material, which is available to authorized users.Published online: November 14, 2019Brucellosis and leptospirosis are neglected bacterial zoonotic diseases of veterinary and public health importance worldwide (Seleem et al 2010; de Vries et al 2014)
Zone 2 (‘‘moderate interface area’’) was represented by areas 20–40 km away from the reserve, with moderate wildlife–livestock interactions, while zone 3 (‘‘low interface area’’) was the area more than 40 km away from the reserve, where wildlife–livestock interactions are more rare (Ogutu et al 2009; Bhola et al 2012). These defined ecological zones allowed the analysis of risk factors associated with Leptospira spp. and Brucella spp. seroprevalence to be compared across the various zones with different levels of wildlife–livestock interactions and varied land use types
The overall apparent animal-level seroprevalences of Brucella spp. and Leptospira spp. were 36.9% and 23.5%, respectively

Summary

Introduction

Electronic supplementary material: The online version of this article Brucellosis and leptospirosis are neglected bacterial zoonotic diseases of veterinary and public health importance worldwide (Seleem et al 2010; de Vries et al 2014). Bovine brucellosis is caused by facultative intracellular gram-negative coccobacilli of the genus Brucella (Seleem et al 2010). Whereas Brucella abortus is the main causative agent of bovine brucellosis, Brucella melitensis, the species that primarily affects sheep and goats, can occasionally infect cattle (Seleem et al 2010). Bovine leptospirosis is caused by pathogenic spirochetes of the genus Leptospira (de Vries et al 2014)

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