Passive immunization is a crucial parameter for prevention of human rabies. Presently as World Health Organization (WHO) strongly advocates local infiltration of rabies immunoglobulin in and around the bite wound, we feel that there is no basis for calculating the dose of immunoglobulin based on body weight. Keeping this in view we conducted both in vitro and in vivo studies to know whether the dose of immunoglobulin can be reduced and still obtain complete neutralization of the virus. In vitro neutralization studies were conducted using CVS strain of virus and BHK 21 cells. In vivo experiments were conducted in 4 weeks old Swiss albino mice by initial challenge with CVS followed by infiltration with increasing dilutions of either human rabies immunoglobulin (HRIG) and equine rabies immunoglobulin (ERIG). In vitro studies showed that a dose of 100 FFD 50 of CVS was neutralized by increasing dilution of both HRIG and ERIG and 100% neutralization was observed with HRIG and ERIG in as low quantities as 0.025 IU. In mice studies there was 100% survival of mice infiltrated with 0.025 IU of both HRIG and ERIG compared with 100% mortality in mice infiltrated with normal saline. These results suggest that it is possible to reduce the dose of rabies immunoglobulins by at least 16 times the presently advocated dose. These findings needs to be further evaluated using larger animal models and street viruses prevalent in nature but cannot serve as recommendations for use of RIG for passive immunization in humans.

Bats are known to be reservoirs of several medically important viruses including lyssaviruses. However, no systematic surveillance for bat rabies has been carried out in India, a canine rabies endemic country with a high burden of human rabies. Surveillance for rabies virus (RABV) infection in bats was therefore carried out in Nagaland, a north-eastern state in India at sites with intense human-bat interfaces during traditional bat harvests. Brain tissues and sera from bats were tested for evidence of infection due to RABV. Brain tissues were subjected to the fluorescent antibody test for detection of viral antigen and real-time reverse transcriptase PCR for presence of viral RNA. Bat sera were tested for the presence of rabies neutralizing antibodies by the rapid fluorescent focus inhibition test. None of the bat brains tested (n = 164) were positive for viral antigen or viral RNA. However, rabies neutralizing antibodies were detected in 4/78 (5·1%) bat sera tested, suggesting prior exposure to RABV or related lyssaviruses. The serological evidence of lyssaviral infection in Indian bats may have important implications in disease transmission and rabies control measures, and warrant extensive bat surveillance to better define the prevalence of lyssaviral infection in bats.

Cases of meningoencephalitis with no known etiology remain a major challenge to clinical management of brain infections across the world. In this study, we detected and characterized the whole-genome of primate erythroparvovirus 1 (B19V) in cases of meningoencephalitis in India.

Background Rabies is still endemic in India causing an estimated 20,000 human deaths a year. Free roaming dogs and unvaccinated owned dogs play a major role in the maintenance of the disease. Dog vaccination is the most crucial aspect of rabies prevention and control strategies; therefore vaccine immunogenicity and longevity are important determinants of the efficiency of rabies control efforts. Methods In this study at Madras Veterinary College, India, a total of 297 serum samples were collected from owned dogs that were vaccinated against rabies. Data regarding age, gender, breed, neuter status and last date of vaccination were collected at the time of blood collection. The level of rabies virus neutralising antibodies in the sera of these dogs was measured through rapid focus fluorescence inhibition test. The factors associated with protective level of rabies antibodies in vaccinated dogs were investigated through multivariable regression analysis. Results This cross‐sectional investigation shows that only 40% (119/297) of the all the dogs in the study showed presence of protective level of anti‐rabies antibodies, and 40% (72/180) of the dogs vaccinated within the last year showed presence of protective levels of antibodies causing concern about rabies vaccine quality and its impact on rabies control. The study also shows that older and neutered dogs are more likely to have protective titre among vaccinated dogs, while non‐descript breed dogs are less likely to have a protective titre compared to pure breeds. Conclusion In this study 60% (108/180) of young prima dogs and adult dogs did not show protective levels of antibodies within the year of last rabies vaccination, although they had previous vaccination history. This high percentage of apparent non‐responders is a cause of concern of administration, distribution, storage, potency and quality management of vaccines in India.