Seroprevalence of peste des petits ruminants among domestic small and large ruminants in the semi-arid region of North-eastern Nigeria

Abstract

Background: Recent changes in the host range of peste des petits ruminants (PPR) virus coupled with the presence of a huge ruminant population in the study area has stimulated our interest to carry out a sero-survey for PPR among the different domestic ruminant populations of semi-arid region of North-eastern (NE) Nigeria. Materials and Methods: The prevalence of PPR virus antibodies among domestic animals (goat, sheep, cattle and camel) populations in NE Nigeria was studied using virus neutralisation test (VNT) and competitive enzyme-linked immunosorbent assay (c-ELISA). Results: An overall seroprevalence of 57% and 55% were revealed using VNT and c-ELISA, respectively. Significant difference (p<0.05) in the prevalence of PPR antibodies was noted between the different species of animals tested. Highest seroprevalence of 76.5% was found in sheep followed by a decreasing order of prevalence in goat 51.6%, camels 27.8% and cattle 16.7%. Similar pattern of prevalence was noted when the sera were tested for PPR using c-ELISA antibody. There was no significant difference in the sensitivity of both the procedures (VNT and c-ELISA) when used for the detection of PPR antibody in test sera. However, differences were noted in their specificity based on the degree of cross reactivity between PPR and rinderpest (RP) antibodies. Higher percentage of PPR positive sera (goats 64.8% and sheep 63.8%) cross-reacted with RP virus in VNT. None of the PPR positive sera from cattle and camels cross-reacted with RP virus in VNT and c-ELISA. Significant difference in gender and age was noted in the prevalence of PPR antibody among goats and sheep. Specificall, higher prevalence was found in females and the seroprevalence increased with age among the different age groups of goats studied. Analysis of the seasonal distribution of prevalence of PPR antibody in positive samples did not reveal any significant difference between seasons. Conclusion:We conclude that PPR virus is actively circulating among the ruminant and dromedary populations and that the infection may be endemic in the study area. Significant findings from our study indicate that cattle and camel could play a key role in the epidemiology of PPR, especially in areas like the one under this study where small ruminants are reared alongside cattle and/or camels. Further studies are necessary to fully elucidate, the pivotal roles of cattle and camel in the transmission cycle of PPR virus. © The authors.