Epidemiological Analysis, Serological Prevalence and Genotypic Analysis of Foot-and-Mouth Disease in Nigeria 2008-2009

Abstract

The epidemiological situation of foot-and-mouth disease virus (FMDV) is uncertain in Nigeria, where the disease is endemic, and the majority of outbreaks are unreported. Control measures for FMD in Nigeria are not being implemented due to the absence of locally produced vaccines and an official ban on vaccine importation. This study summarizes the findings of a 3-year study aimed at quantifying the seroprevalence of FMD, its distribution in susceptible species and the genetic diversity of FMDV isolated from the Plateau State of Nigeria. A 29% FMD prevalence was estimated using 3ABC enzyme-linked immunosorbent assay (3ABC ELISA). Farms with suspected FMD nearby, with contact with wildlife, that used drugs or FMD vaccines or with >100 animals, and animals of large ruminant species and in pastures other than nomadic grazing were significantly (P<0.05) associated with FMD. Antibodies against five FMDV serotypes, (A, O, SAT1, SAT2 and SAT3) were detected by the virus neutralization test (VNT) at various titres (<100->800) from all tested sera from most parts of the region. This is probably the first report of the presence of FMDV SAT3 in Nigeria. Further studies to investigate the potential probable presence and prevalence of SAT 3 virus in Nigeria are required. Tissue samples collected from clinical animals were positive for FMDV. Virus isolates were sequenced and confirmed as serotype A. All of the isolates showed marked genetic homogeneity with >99% genetic identity in the VP1 region and were most closely related to a previously described virus collected from Cameroon in 2000. This study provides knowledge on the epidemiological situation of FMD in Plateau State, Nigeria, and will probably help to develop effective control and preventive strategies for the disease in Nigeria and other countries in the West African subregion.