ABSTRACT
BACKGROUND: There have been previous reports of inapparent infection and intermittent secretion of rabies virus in the saliva of apparently healthy dogs in some African countries, including Nigeria. OBJECTIVE: The study was therefore aimed at examining the carrier status of rabies in apparently healthy Nigerian dogs in the settlement areas studied. METHODS: Ninety-two swabs samples from oral mucosae of domestic dogs (mongrels) without vaccination history were assayed for lyssaviruses by tissue culture isolation test in Vero cells. RESULTS: Rabies or rabies-related viruses were recovered from eighteen, representing 19.6% of the samples. The study showed that lyssaviruses were present in 4 out of the 6 settlements of the study areas. Among the areas where the viruses were present, the rate of isolation ranged from 11.1% to 66.7%. Female dogs had a little higher infection rate (12.0%) than their male counterparts (7.6%). Among age groups, the highest rate of infection (66.7%) was detected in dogs aged one to 3 years while the rate of 3.7% was found in dogs aged less than one year. CONCLUSION: The results of this study agree with the carrier state of rabies in domestic dogs, the common reservoir hosts of its etiologic agents in Nigeria and the rest of Africa andAsia; this is a serious threat to humans in these settlements. Although the load of infective virus in saliva is lower than that in brain, saliva collection for rabies diagnosis is simple, safer, faster and cheaper. Thus we suggest that saliva samples could be used as an alternative to brain specimens for rabies virus antigen testing in dogs, especially, when it is not practicable to obtain brain specimen.
