Spatial and seasonal patterns of FMD primary outbreaks in cattle in Zimbabwe between 1931 and 2016

Laure Guerrini,Alexandre Caron,Felistas Ndhlovu,Michel De Garine-Wichatitsky,Vladimir Grosbois,Chris Foggin,Eric Etter,Chenjerai Njagu,Mathieu Bourgarel,Davies Mubika Pfukenyi,Jérémy Bouyer

doi:10.1186/s13567-019-0690-7

Abstract

Foot and mouth disease (FMD) is an important livestock disease impacting mainly intensive production systems. In southern Africa, the FMD virus is maintained in wildlife and its control is therefore complicated. However, FMD control is an important task to allow countries access to lucrative foreign meat market and veterinary services implement drastic control measures on livestock populations living in the periphery of protected areas, negatively impacting local small-scale livestock producers. This study investigated FMD primary outbreak data in Zimbabwe from 1931 to 2016 to describe the spatio-temporal distribution of FMD outbreaks and their potential drivers. The results suggest that: (i) FMD outbreaks were not randomly distributed in space across Zimbabwe but are clustered in the Southeast Lowveld (SEL); (ii) the proximity of protected areas with African buffalos was potentially responsible for primary FMD outbreaks in cattle; (iii) rainfall per se was not associated with FMD outbreaks, but seasons impacted the temporal occurrence of FMD outbreaks across regions; (iv) the frequency of FMD outbreaks increased during periods of major socio-economic and political crisis. The differences between the spatial clusters and other areas in Zimbabwe presenting similar buffalo/cattle interfaces but with fewer FMD outbreaks can be interpreted in light of the recent better understanding of wildlife/livestock interactions in these areas. The types of wildlife/livestock interfaces are hypothesized to be the key drivers of contacts between wildlife and livestock, triggering a risk of FMD inter-species spillover. The management of wildlife/livestock interfaces is therefore crucial for the control of FMD in southern Africa.

Highlights

Foot and Mouth Disease (FMD), known since the sixteenth century [1], is a highly contagious viral disease, infecting domestic and wild cloven-hoofed animals [2]
Outbreaks followed by the Matabeleland region and the Central regions; (ii) distance to protected areas was significantly associated with Foot and mouth disease (FMD) primary outbreaks in the Southeast Lowveld (SEL) and Matabeleland regions with the presence in both regions of extensive wildlife/livestock interfaces; (iii) seasonality but not rainfall influenced the occurrence of FMD outbreaks in both the SEL and Matabeleland regions but differently indicating a differential role of wildlife/livestock interfaces; (iv) and the political context and its socio-economic consequences influenced the occurrence of FMD outbreaks with political and economic instability being linked with a surge in primary outbreak numbers
The dataset of primary outbreaks recorded over a period of 85 years was identified “manually” by local Department of Livestock and Veterinary Services (DLVS) experts who closely monitored outbreaks in the last decades

Summary

Introduction

Foot and Mouth Disease (FMD), known since the sixteenth century [1], is a highly contagious viral disease (single-stranded RNA virus), infecting domestic and wild cloven-hoofed animals [2]. Recent studies have targeted different aspects of FMD epidemiology in Africa: investigation on the role of wildlife/livestock interfaces on FMD inter-species transmission [12, 20, 21], the ecology of the different serotypes [22,23,24], the risk factors linked to animal husbandry [25] and the role of the environment [26] Taking into account this new knowledge on the disease, sound risk-based surveillance and control strategies for FMD are needed and should be more respectful of local livelihoods and the environment [27]. This study should contribute to identify hotspots and drivers associated with FMD outbreaks, suggests mechanisms for disease emergence at the wildlife/livestock interface and is expected to provide useful information to decision makers for tailoring risk-based surveillance of FMD in Zimbabwe

Materials and methods

Results

Discussion