Molecular Epidemiology of Foot-and-Mouth Disease Viruses in the Adamawa Province of Cameroon

Abstract

Foot-and-mouth disease virus (FMDV) causes a highly contagious viral disease of even-toed ungulates and is one of the most important economic diseases of livestock. Most studies of FMDV are done in countries where control measures are being implemented. In contrast, in areas such as sub-Saharan Africa, where FMDV is endemic and new strains are likely to emerge, there are only sporadic submissions to the World Reference Laboratory, Pirbright, United Kingdom. This paper describes the molecular epidemiology of FMDV in the Adamawa province of Cameroon based on a population sample of cattle herds. Serotypes SAT2 and A were isolated in the cross-sectional study. SAT2 isolates were all similar, with phylogenetic distances of <6%, and were most closely related to published sequences of isolates from Eritrea and Saudi Arabia. Serotype A isolates were more variable, with phylogenetic distances of 0 to 11%, and were most closely related to historic isolates from Cameroon. Use of a population-based sample gives a representative sample of virus diversity and will improve our understanding of the evolution of FMDV and its epidemiology. A supplementary study of pigs passing through the railhead collection yard at Ngaoundere detected a serotype O virus. A third pilot longitudinal study monitored viral persistence in three cattle herds over 12 months, and serotype O and A viruses were recovered from a herd 12 months after it was first recorded as being infected with SAT2 virus. The pig type O isolate was not closely related to that recovered from the cattle, suggesting that the pigs had not introduced the O virus into the cattle herds.

Foot-and-mouth disease virus strains and examination of exposure factors associated with seropositivity of cattle herds in Nigeria during 2007–2009

“…Similar to the relationship described above between serotype O isolates, the relationship between SAT-2 serotypes in Nigeria and Sudan can be explained by trade of cattle from Sudan across to Cameroon (through the Ngoui market on the border with the Central African Republic) near the border region with Nigeria (Bronsvoort et al, 2004). …”

“…All cultures showing FMDV cytopathic effect were harvested and serotyped using an ELISA. All viruses that were recovered from epithelial or vesicular fluid samples were sequenced using a WRLFMD standard protocol (Bronsvoort et al, 2004). Furthermore, a phylogenetic analysis of FMDV isolates was conducted using regions of a VP1 sequence to calculate distance values between isolates.…”

“…Samples were packaged according to international standard for transportation of infectious materials affecting animals (OIE, 2008). At the WRLFMD, all samples were tested for diagnosis of FMDV by virus isolation and reverse transcription (rt) PCR (Bronsvoort et al, 2004). Virus isolation was attempted from all samples in primary bovine thyroid cell culture.…”

Predicting antigenic sites on the foot-and-mouth disease virus capsid of the South African Territories types using virus neutralization data

“…FMD is of particular importance in Africa where the disease is endemic and six of the seven immunologically distinct serotypes occur (Thomson, 1994;Vosloo et al, 2002). Although foot-and-mouth disease virus (FMDV) causes a clinically indistinguishable vesicular disease in clovenhoofed animals, the seven serotypes display different geographical distributions and epidemiology (Samuel & Knowles, 2001;Bastos et al, 2001Bastos et al, , 2003aKnowles & Samuel, 2003;Bronsvoort et al, 2004).…”

Epidemiological study on foot and mouth disease in cattle: Seroprevalence and risk factor assessment in Kellem Wollega Zone, West Ethiopia

“…Foot and mouth disease (FMD) is a highly contagious viral disease of cloven-footed animals and is one of the most important economic diseases of livestock by fever and vesicular eruptions in the mouth, on the feet and teats (Bronsvoort et al, 2004). FMD is caused by a virus of the genus Aphthovirus, in the family Picornaviridae, of SAT-3, and Asia-1 (OIE, 2004).…”