Characterization of transboundary foot-and-mouth disease viruses in Nigeria and Cameroon during 2016

Authors: EHIZIBOLO, DAVID - National Veterinary Research Institute; FISH, IAN - Orise Fellow; BRITO, BARBARA - Orise Fellow; BERTRAM, MIRANDA - Orise Fellow; ULARAMU, HUSSAINI GULAK - National Veterinary Research Institute; LAZARUS, DAVID DAZHIA - National Veterinary Research Institute; WUNGAK, YILTAWI - National Veterinary Research Institute; Smoliga, George; Hartwig, Ethan; Pauszek, Steven; DICKMU, SIMON - Lanavet; ABDOULKADIRI, SOULEY - Lanavet; Arzt, Jonathan

Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2019
Publication Date: 12/27/2019
Citation: Ehizibolo, D.O., Fish, I., Brito, B., Bertram, M.R., Ularamu, H., Lazarus, D., Wungak, Y., Smoliga, G.R., Hartwig, E.J., Pauszek, S.J., Dickmu, S., Abdoulkadiri, S., Arzt, J. 2019. Characterization of transboundary foot-and-mouth disease viruses in Nigeria and Cameroon during 2016. Transboundary and Emerging Diseases. https://doi.org/10.1111/tbed.13461.
DOI: https://doi.org/10.1111/tbed.13461

Interpretive Summary: Foot and mouth disease (FMD), caused by FMD virus (FMDV), is an important livestock disease that causes substantial animal health problems and economic losses in many countries in Africa and Asia, where the disease exists. There are 5 distinct types of FMDV which exist in Africa, which are known as Serotypes A, O, SAT1, SAT2, and SAT3. The presence of these serotypes and their subcategories is in frequent flux in time and space; yet up to date knowledge of the presence of the types is important for regional control programs including vaccine selection and regulation of animal movement. The current study identified four of the serotypes A, O, SAT1, and SAT2 in Western Africa between 2014-16. Tracing the genetic signatures of the viruses suggested that individual strains move frequently and rapidly across nations, typically following livestock trade routes. It was found that some viruses had common ancestors spanning West Africa, East Africa, and North Africa. These findings have implications for FMDV control in Nigeria, Cameroon, and other regions where FMDV is endemic.

Technical Abstract: Continuous surveillance for foot-and-mouth disease (FMD) in endemic settings such as West Africa is imperative to support improved local and regional control plans, with the long term goal of regional eradication. This paper describes the genetic characterization of FMD viruses (FMDV) obtained from outbreaks in Nigeria and Cameroon during 2016 and from archival samples retrieved from a 2014 outbreak in Nigeria. These viruses were analyzed in the context of previously published FMDV sequences from the region. Four FMDV serotypes: O, A, SAT1 and SAT2 were detected. Phylogenetic analyses of the VP1 coding sequences indicate the continuity of FMDV serotype O East Africa-3 (EA-3), serotype A AFRICA genotype G-IV, and serotype South African Territories (SAT) 2 lineage VII. The FMDV SAT1 topotype X, which emerged in Nigeria in 2015, is now established in the region, and SAT1 is reported for the first time from Cameroon. Additionally, a novel re-introduction of the serotype O West Africa (WA) topotype in Nigeria is described herein. Our findings indicate a consistent, pan-serotypic relationship between FMDV strains detected in Cameroon and Nigeria. Additionally, FMDV strains from West Africa obtained in this study were genetically related to those occurring in East and North Africa. These phylogenetic relationships suggest that animal movements (pastoralism and/or trade) are important factors for virus spread across the African continent. These data provide critical baselines which are a necessary component of Stage 0 and 1 of the Progressive Control Pathway of FMD (PCP-FMD). Specifically, characterizing the existing strains (risk) provides the basis for the comprehensive risk-based control plan which is the requisite criteria for Nigeria’s transition to Stage 2 of PCP-FMD, and for coordinated regional control of FMD.