What happens with rabies disease after successive inoculations of rabies virus from different genetic lineages?

Abstract

Background: Rabies is a neurological zoonosis causing a lethal infection in all mammalians, including humans. The etiological agent of the illness is the rabies virus (RABV) that belong to the genus Lyssavirus, family Rhabdoviridae. According to the World Health Organization rabies is a neglected disease causing about 60.000 deaths people by year worldwide mainly in Africa and Asia. Rabies could be maintained by aerial and terrestrial cycles, the aerial cycle has bats as the main reservoir and in most developing countries dogs represent the major rabies reservoir in terrestrial cycle. The RABV is a RNA virus and differences in genome of the virus could be identified according to the reservoir. Methods & Materials: This work was made to understand the influence in pathogenesis of rabies disease of the differences in the genome of RABV. To answer this question, three samples of RABV isolated from different reservoirs (dog, haematophagous bat and non haematophagous bat) with different genetic lineages were selected. After that each one of the samples was submitted to ten successive inoculations in mice by intracerebral route. The group of mice was formed by six animals that received food and water at libidum. The animals were monitored daily and the development of clinical signs and the date of death were recovered. Results: The rabies had a variable incubation period between 3 to 5 days in the inoculated mice, the clinical course of the infection was 4 days and all mice experimentally infected with RABV developed neurological signs as apathy, ataxia, muscle spasms paralysis and death. Conclusion: Our work shown the RABV maintained highly pathogenic and ten successive inoculations of the virus were not suitable to attenuate the virus. These findings highlight the importance of the understanding pathogenesis of RABV and its value as an aid to support rabies surveillance.