A Study on the Ocular Infection with Rabies Virus in Mouse

Introduction: The most common mode of rabies virus transmission is through a bite wound or contact of broken skin with saliva of a rabid animal. Various other routes of virus transmission include exposure of mucous membranes (i.e. eyes, nose, and mouth) to infected saliva of a rabid animal, aerosol transmission, and corneal transplantation. Laboratory workers during work with rabies virus and veterinarians during examination and surgery of rabid animals may be at risk for exposure to saliva or other infectious fluids splashing into their eyes. The aim of this study was to investigate the possibility of ocular rabies pathogenesis in mice as an animal model. Our results will determine if rabies virus strains challenge virus standard (CVS) and street rabies virus (SRV) are able to infect the central nervous system (CNS) of mice through the ocular route. Methods: This study was performed in two experiments. In experiment 1, different lethal doses of fixed rabies virus strain CVS were made and instilled into both eyes of test mice. In experiment 2, concentrated rabies virus strains CVS and SRV were instilled into both eyes of the test mice. Mice in all groups were kept for 3 months and tested by fluorescent antibody test (FAT) for detection of the presence of viral antigen in brain tissue. Results: Mice with ocular instillation of fixed and street rabies viruses developed no clinical symptoms of rabies and all were healthy and alive during the 3-month observation period. The FAT results were negative in both experiments. Conclusion: Our results suggest that CVS and SRV viruses are not able to infect the CNS of mice via intact conjunctiva and cornea.