The Seroepidemiology of a Neglected Zoonotic and Livestock Pathogen in Free-Ranging Bovids: Leptospirosis in African Buffaloes (Syncerus caffer).

Wynand Goosen,Mark Hamish Moseley,Tanya Jane Kerr,Michele Miller,Andrew Potts

doi:10.3390/pathogens10091072

Abstract

Multi-host pathogens are challenging to control and are responsible for some of the most important diseases of humans, livestock, and wildlife. Leptospira spp. are some of the most common multi-host pathogens and represent an important cause of zoonotic infections and livestock productivity loss in the developing world, where contact with wildlife species is common. Although there is increasing evidence that cattle in Africa harbour a broad diversity of Leptospira genotypes and serovars, little is known about the epidemiology of these pathogens in wild bovids, such as African buffaloes (Syncerus caffer). Using microscopic agglutination testing (MAT) on serum samples collected from free-ranging buffaloes (n = 98) captured in the Hluhluwe-iMfolozi Park (HiP), South Africa, we demonstrated an overall seroprevalence of 21% with seropositivity almost exclusively limited to serovar Tarassovi (serogroup Tarassovi). Moreover, we found no evidence of seropositivity in unweaned calves and showed temporal- or herd-specific variation in exposure risk, and increased probability of seropositivity (OR = 5.44, 95% CI = 1.4–27) in female buffaloes. Together, these findings demonstrate that free-ranging African buffaloes are exposed to Leptospira spp. infections, providing insights into the epidemiology of an emerging Leptospira serovar in herds with an absence of any disease control and minimal management.

Highlights

Wildlife can play an important role in the epidemiology of multi-host pathogens of humans and livestock by maintaining pathogens in reservoirs of epidemiologically connected reservoir host populations or environments [1] where traditional control measures, such as vaccination, may be challenging
Using microscopic agglutination typing (MAT) on serum samples collected from free-ranging buffaloes captured in 2016, 2018, and 2019 in the Hluhluwe-iMfolozi Park (HiP) in KwaZulu-Natal (KZN), South Africa, we aimed to (i) characterise the seroprevalence and serological diversity of Leptospira spp
When including animals that tested positive for Leptospira on either sample in 2016, the microscopic agglutination testing (MAT) results revealed a combined seroprevalence, for all years and age groups, of 21% (21 in 98, 95% CI 14–31%)

Summary

Introduction

Wildlife can play an important role in the epidemiology of multi-host pathogens of humans and livestock by maintaining pathogens in reservoirs of epidemiologically connected reservoir host populations or environments [1] where traditional control measures, such as vaccination, may be challenging. The transmission of pathogens from domestic animals [2] or livestock [3] to wildlife has been shown to have important implications for the conservation of iconic wildlife species. Understanding the epidemiology of these pathogens in their wildlife reservoir hosts is critical to mitigating their effects in humans, livestock, and wildlife. Leptospira spp. are one of the most common and diverse multi-host pathogens and are an important cause of zoonotic infections and livestock productivity loss. While rodents are frequently implicated as sources of human infection, there is increasing evidence that, in some contexts, livestock may play a key role as reservoir hosts in Africa [6] where molecular [7] and serological [8]

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