Characterization of Foot-and-Mouth Disease Viruses in Zambia-Implications for the Epidemiology of the Disease in Southern Africa.

Liywalli Mataa,Frank Banda,Mokganedi Mokopasetso,Tingiya Sikombe,Nick J Knowles,Henry L Kangwa,Elliot M Fana,Phiyani Lebea,Donald P King,Yona Sinkala,Melvyn Quan,Jemma Wadsworth

doi:10.3390/v13112195

Abstract

The livestock industry supports livelihood and nutritional security of at least 42% of people in the Southern African Development Community region. However, presence of animal diseases such as foot-and-mouth disease poses a major threat to the development of this industry. Samples collected from FMD outbreaks in Zambia during 2015–2020, comprising epithelial tissues samples (n = 47) and sera (n = 120), were analysed. FMD virus was serotyped in 26 samples, while 92 sera samples tested positive on NSP-ELISA. Phylogenetic analysis revealed notable changes in the epidemiology of FMD in Zambia, which included: (i) introduction of a novel FMDV SAT-3 (topotype II) causing FMD cases in cattle in Western Province; (ii) emergence of FMDV serotype O (topotype O/EA-2) in Central, Southern, Copperbelt, Western, Lusaka Provinces; and (iii) new outbreaks due to SAT -2 (topotypes I) in Eastern Zambia. Together, these data describe eight different epizootics that occurred in Zambia, four of which were outside the known FMD high-risk areas. This study highlights the complex epidemiology of FMD in Zambia, where the country represents an interface between East Africa (Pool 4) and Southern Africa (Pool 6). These changing viral dynamics have direct impacts on FMD vaccine selection in the SADC region.

Highlights

Foot-and-mouth disease (FMD) is a highly contagious transboundary animal disease (TAD) that is a major concern to livestock industries throughout the world
This study aimed to characterize FMD viruses causing recent cases in Zambia, in order to provide data to help understand the epidemiology of the disease in Southern Africa
Out of the eight primary outbreaks, four (50%) were reported outside the three known high-risk areas in Zambia (Figure 2): in October 2015 from Shang’ombo district of Western Zambia; in March 2018 and January 2019 in Chisamba district of Central Zambia and during March 2019 in Lundazi and Vubwi districts of Eastern Zambia (Figure 2)

Summary

Introduction

Foot-and-mouth disease (FMD) is a highly contagious transboundary animal disease (TAD) that is a major concern to livestock industries throughout the world. The disease is caused by the FMD virus (FMDV), which affects cloven-hoofed animals. In Southern Africa (Pool 6), three serotypes (SAT 1-3) are endemic with sporadic incursions of serotype O and A recorded in Northern Zambia as a consequence of spillover from Pool 4 (East Africa) [8,9,10]. The distribution of these diverse serotypes and subtypes of FMDV is subject to change, and requires continuous monitoring [10,11]

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Conclusion