Rabies Vaccination Coverage and Antibody Profile of Owned Dogs in Abuja, Nigeria

Abstract

ObjectiveTo determine the vaccination status of owned dogs, assess therabies antibody titre of vaccinated dogs and risk factors associatedwith vaccination of dogs in Abuja, Nigeria.IntroductionRabies is a zoonotic disease of high public health importance1.There have been documented reports of rabies in vaccinateddogs2. Rabies is enzootic in domestic dogs in Nigeria. Hence,annual vaccination campaigns of dogs are advocated with the aimof rabies elimination. Vaccination status, type of vaccination andthe immunogenicity of the various rabies vaccines used in AbujaNigeria has not been studied. To date, no effective medical therapyhas been established for rabies3. Most human rabies deaths occurin the developing countries and though effective and economicalcontrol measures are available their application in developingcountries is hampered by a range of economic, social and politicalfactors. It is widely recognized that the number of deaths officiallyreported in most developing countries greatly underestimates the trueincidence of disease, with several factors contributing to widespreadunderreporting3. Preventive vaccination against rabies virus is ahighly effective method for preventing rabies in humans and animals3but do people vaccinate and how long does the immunity conferredby the vaccine remain protective in the dogs in Abuja?. Rabies hashigh financial expenditure burden on any country where it is endemicmainly associated with costs incurred on post-exposure prophylaxis(determined by the type of vaccine, vaccine regimen and route ofadministration as well as the type of immunoglobulin used).MethodsDog serum samples (n=276) were collected from Abuja the FederalCapital Territory (FCT) Nigeria, from 5 locations (Phase 1, 2, 3,Gwagwalada and Kubwa) based on availability and owners consent.Rabies antibody serum titer was determined using an indirect enzymelinked immuno-sorbent assay. Face to face structured questionnaireswere used to obtain demographic and zoographic information fromthe dog owners. Associations between the demographic variables,vaccination status and rabies antibody titer of each dog were assessedusingχ2analysis.ResultsOf the dogs sampled, 229 (83%) had certified antirabies vaccinationrecord. The dogs sampled, which were vaccinated from Phase I, II,III and the satellite towns were; 109/118 (92.37%), 32/33 (96.97%),48/49 (97.96%) and 40/76 (52.63%), respectively. A total of 276serum samples were collected, processed and analyzed during thisstudy. Out of the 276 dogs sampled, 239 (86.6%) had rabies antibodytitre≥0.6EU/ml whilst 37 (13.4%) had less than 0.6EU/ml. Therewas a marked decline in rabies antibody titre with increase in time.Out of the 228 exotic breeds of dogs sampled, 218 (95.6%) werevaccinated whilst 11 (22.9%) of the 48indigenous breed of dogssampled were vaccinated. All the exotic breed of dogs had rabiesantibody titre≥0.6EU/ml whilst 37 (77.1%) of the indigenousbreed of dogs had less than 0.6 EU/ml levels of rabies antibody titre.All dogs within 6 months to 1 year and greater than 10 years of agehad≥0.6EU/ml rabies antibody titre whilst dogs within 1-5 years had1 (0.5%) and 36(69.2%) dogs of age 6-10 years had rabies antibodytitre < 0.6EU/ml. Twelve (7.6%) of the males and 25 (21.2%) of thefemales had less than 0.6EU/ml rabies antibody titre. All the dogsacquired by importation and from breeders had rabies antibody titre≥0.6EU/ml whilst 37 (27.2%) of the dogs acquired from friends hadless than 0.6EU/ml rabies antibody titre.Significant associations were observed between breed (χ2= 203,df = 1, P-value < 0.05), age (χ2= 172, df = 3, P-value < 0.05), sex(χ2= 10.75, df = 1, P-value < 0.05), source (χ2= 43.99, df = 2, P-value< 0.05), rabies vaccination status (χ2= 276.00, df = 2, P-value < 0.05)and the rabies antibody prevalence of sampled dogs.ConclusionsThis cross-sectional study shows that not all dog owners vaccinatetheir dogs and that the vaccines conferred protection beyond12 months. The Preventive vaccination against rabies virus is ahighly effective method for preventing rabies in humans and animals.Policies to enhance mass mandatory annual vaccination to achieve70% coverage should be implemented in order to eradicate rabies.