Characterisation and control of foot-and-mouth disease outbreaks in Zambia between 2015 and 2020

Abstract

Repeated outbreaks of transboundary animal diseases, particularly foot-and-mouth disease (FMD), have posed significant challenges to the development of the livestock industry in Zambia and the broader Southern African region. This sector is crucial to national food security and livelihoods and holds potential for greater economic contribution due to Zambia’s favourable natural resources. This study explores the molecular epidemiology of the FMD virus (FMDV) in Zambia, focusing on the emergence and spread of serotypes O/EA-2, A, SAT-2, and SAT-3. A scoping review of diagnostic assays for SAT serotypes recommended the combined use of SAT-1, SAT-2, and SAT-3 lateral flow devices (LFDs) for effective viral detection, with the PrioCheck®-NSP kit proving highly effective for non-structural protein antibody identification. The immunogenicity of the O-Manisa vaccine was assessed in cattle challenged with the O/EA-2 outbreak strain, revealing significantly higher antibody titres in double-dosed animals at 56 days post-vaccination (dpv) compared to single-dosed groups. Furthermore, a strong positive correlation was observed between virus neutralisation tests and solid-phase competitive ELISA (SPCE), supporting the use of SPCE in immunogenicity assessments, particularly in resource-constrained settings. The findings underscore the complexity of FMD epidemiology in Zambia and highlight the urgent need for continuous monitoring of serotype O/EA-2 and a coordinated regional strategy for FMD control across Southern Africa.