Rabies Vaccination and Immune Status of Owned Dogs in Zaria, Nigeria

Abstract

Rabies prevention in both humans and animals is possible by vaccination. The domestic dog (Canis familiaris) is the major reservoir in rabies-endemic Asia and Africa. Vaccination of dogs remains the most cost-effective option for rabies control in these regions and herd immunity is achievable when up to 70% of dogs in a community are immunised against the disease. This study was carried out to determine the vaccination and immune status of owned dogs in Zaria. A total of 189 serum samples were collected from dogs in Zaria. Accompanying information obtained included the vaccination status of the dogs, sex, location and management system. oSerum samples were stored at -20C until shipped on dry ice to the rabies laboratory of the CDC, Atlanta Georgia. The samples were tested for virus neutralising antibodies by the rapid fluorescence focus inhibition test (RFFIT) using the challenge virus standard (CVS-11 strain). Only 32 (16.9%) of the dogs in this study had a history of vaccination and out of this number, 23 (71.9%) had virus neutralizing antibodies (VNA) to CVS-11. Five dogs reportedly vaccinated had no demonstrable VNA and 20 (14.8%) had VNA even though they were said to be unvaccinated by their owners. Dogs are kept with no collars or vaccination certificates and tags, so it was difficult to verify the claims by some of the dog owners. The results of the study indicate very low vaccination coverage, but appreciable seroconversion rate among vaccinees. Vaccination of dogs is still a viable option for rabies control in rabies-endemic areas and mass vaccination of dogs should be encouraged if the disease is to be controlled in rabies-endemic areas.