Spatiotemporal epidemiology of rabies at an interface between domestic dogs and wildlife in South Africa

Michael Grover,Pim Polak,Claude T Sabeta,Anne Conan,Darryn L Knobel,Paul R Bessell,Bjorn Reininghaus

doi:10.1038/s41598-018-29045-x

Abstract

We characterized the spatiotemporal epidemiology of rabies from January 2009 through March 2014 across the interface between a wildlife reserve and communal livestock farming area in South Africa. Brain tissue from 344 animals of 28 different species were tested for lyssavirus antigen. Of these, 146 (42.4%) samples tested positive, of which 141 (96.6%) came from dogs. Brain samples of dogs were more likely to test positive for lyssavirus antigen if they were found and destroyed in the reserve, compared to samples originating from dogs outside the reserve (65.3% vs. 45.5%; odds ratio (OR) = 2.26, 95% confidence interval (CI) = 1.27–4.03), despite rabies surveillance outside the reserve being targeted to dogs that have a higher index of suspicion due to clinical or epidemiological evidence of infection. In the reserve, dogs were more likely to test positive for rabies if they were shot further from villages (OR = 1.42, 95% CI 1.18–1.71) and closer to water points (OR = 0.41, 95% CI 0.21–0.81). Our results provide a basis for refinement of existing surveillance and control programs to mitigate the threat of spillover of rabies to wildlife populations.

Highlights

Rabies is an acute, progressive and usually fatal myeloencephalitis that occurs in a wide range of host species
We provide a description of the spatiotemporal epidemiology of rabies in a socio-ecological system with emphasis on its interface between domestic dogs and wildlife, in the eastern part of Mpumalanga Province in South Africa, part of the Greater Limpopo Transfrontier Conservation Area that spans the boundaries of South Africa, Mozambique and Zimbabwe[8]
The reserve shares an unfenced boundary with a Mpumalanga provincial reserve in the north, and the eastern boundary and part of the southern boundaries are open to the Kruger National Park (KNP)

Summary

Introduction

Progressive and usually fatal myeloencephalitis that occurs in a wide range of host species. While all warm-blooded animals appear susceptible to infection with RABV, relatively few species act as reservoir host, which means being capable of sustaining intraspecific transmission of host-adapted virus strains[1]. For RABV, these are typically people (public health programs) or livestock (herd health programs), and include vulnerable or valuable wildlife species (conservation programs), and domestic dogs themselves (animal health and welfare programs). Surveillance and control of multi-host pathogens present particular challenges in complex socio-ecological systems, such as where people and their domestic animals co-exist in environments with diverse wildlife populations. For RABV, this includes an understanding of the risk of transmission from infected reservoir hosts to susceptible target hosts, including data on the movement of rabid dogs into wildlife protected areas[10]. Our findings should further improve existing rabies surveillance and control programs, by providing a basis for management decisions to protect large predator populations from this dangerous viral disease

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