Spontaneous Rabies in a Stray Bitch after Parturition Induced Immunosuppression —Investigating an Impending Outbreak of Rabies with One Health Approach

Abstract

Background: Rabies is endemic in India and every half an hour a person dies of this dreaded disease. Stray roaming dogs, mostly unvaccinated, are most dangerous host in spread of rabies in India and in our state of Himachal Pradesh. Timely prophylaxis is the only method to save animal bite victims, including that of rabid dog bite patients. Objectives: Objective of this study was to investigate an impending outbreak of rabies in Shimla town in the absence of life saving rabies immunoglobulins (RIGs) in the market, and to know the source of infection by using one health approach and using epidemiological tools. Methods: On April 7, 2015, there was a sudden surge in cases of suspected rabid dog bites. Impending rabies outbreak was suspected as there were no RIGs available in the market. A rapid Response Team (RRT) consisting of the author, veterinary doctor, dog squad of Municipal Corporation (MC) Shimla along with the vehicles to impound rabid dogs was constituted to investigate the terror spread by two rabid dogs on biting spree in the Shimla Municipality. Results: A total of 18 people were bitten by suspected rabid dogs within three days period. A black bitch and a brown dog, on the identity of affected people, were captured by the dog squad of Municipality next day on April 8, 2015 and taken to Dog Sterilization Centre, Animal Birth Control (ABC) programme, MC Shimla for observation. The most furious Black bitch died of clinically confirmed symptoms of furious rabies after three days. The second rabid dog, brown in color, died after a month of observation due to paralytic dumb rabies. The brain of the brown dog was extracted for Fluorescent Antibody Testing (FAT) at central research Institute (CRI) Kasauli and was found to be positive for FAT. Follow up of patients was 100% by house to house visit and over telephone and no casualty was reported. Conclusion: While we were working on hypothesis of rabid dogs getting the infection from nearby forest about 8 - 10 KM away but on follow up of the patients, they reported that both the dog and bitch used to stay in the compound of their colony since the bitch was pregnant and there was no history of the bitch moving for away to forests neither any outside dog which was seen near them in the compound. This led us to think of other causes of what must had happened to the bitch that caused her to be rabid as for the past 9 years we had observed bitches becoming rabid after litter birth (Whelping) and making their pups rabid due to licking. Since the carrier state for rabies virus in bitches/dogs is known and a state of immunosuppression after whelping/parturition is also known, therefore there is a possibility of latent rabies virus getting activated due to immunosuppression after litter birth and it is thought to be as one of the probable causes of black bitch getting rabid and inflicting the infection to accompanying brown dog. We need to do further studies to ascertain this phenomenon before coming to a definite conclusion and suspect such a possibility in case a dam suddenly becomes rabid among a pack of stray dogs in rabies endemic countries like ours.