Low level of the immune response against rabies virus in dogs and cats, a cross-sectional study in sheltered animals, Santander, Colombia

Abstract

Rabies is an incurable and fatal progressive viral encephalomyelitis that causes approximately 61,000 deaths a year globally mainly by dog bites, which show the importance of anti-rabies vaccination in dogs to achieve elimination of the disease. In Colombia, multiple cases of human rabies transmitted by dogs and cats have been reported since 1999, showing an increased significance of cats in the transmission of rabies, mainly in rabies of wild origin. Therefore, the aim of the present study was to evaluate the development of neutralizing antibodies in dogs and cats during the mass vaccination campaign of the second half of 2015 in the city of Bucaramanga. For this purpose, a descriptive cross-sectional study with convenience sampling was conducted in 382 dogs and cats (295 dogs, 87 cats), and an evaluation of the humoral immune response of the animals was performed by quantitative ELISA. The prevalence of optimal neutralizing antibodies (>0.5 IU/ml) was only 32.76% (95% CI=28.05-37.46%) in the entire population studied and most of the animals did not have an adequate response to the vaccination, or seroconversion was not detected on them (65.45-95% confidence interval, CI=60.68-70.21%). Significant difference was found between the neutralizing antibody titers in cats and dogs, with a higher neutralizing response in cats. In conclusion, although mass vaccination campaigns for dogs and cats are the most important measure to interrupt virus circulation among the animals, achievement of a good neutralizing immune response in the animals is useful to demonstrate that vaccination has been successful, allowing the maintenance of the required minimum levels of population immunity. These results will allow the implementation of corrective measures in Bucaramanga to achieve better seroconversion rates. Other cities are expected to implement similar seroconversion assessments to verify the quality of effective anti-rabies vaccination in animal populations.

Evaluation of the immune response of dogs after a mass vaccination campaign against rabies in Tunisia

“…We confirm that in this study, vaccination under current field conditions, even with minimal facilities, allows seronconversion. This helps us to establish that, as mentioned in the literature [ 34 – 36 ], mass vaccination campaigns are successful. Indeed, vaccination induces an immune response even in the absence of a sufficient cold chain, meaning that the increase in rabies cases in Tunisia is not necessarily attributable to a failure of the vaccination process.…”

Prevalence of canine heartworm infection in Queensland, Australia: comparison of diagnostic methods and investigation of factors associated with reduction in antigen detection

“…However, this may be related to the age profile of the animals in this trial: female dogs were younger than the male dogs. Alternatively, these differences might be linked to the differences in the immune response mounted by female and male subjects as demonstrated in/with other pathogens and host species [ 91 , 92 ].…”

Organização das ações de campanha de vacinação antirrábica em Colatina, Espírito Santo: relato de experiência

“…Em Santa Maria, Rio Grande do Sul, 30% dos animais não possuíam anticorpos em níveis adequados, já em Campo Grande, Mato Grosso do Sul, o percentual foi de 51% [17][18] . De maneira semelhante um estudo conduzido na Colômbia demonstrou que somente 32% dos animais possuía anticorpos neutralizantes em níveis ótimos (>0,5 UI/ml) 19 .…”

“…O reduzido percentual de animais que apresentam anticorpos satisfatórios pode justificar a necessidade da imunização anual de animais e possível o estabelecimento de uma aplicação de reforço, todavia é necessário que sejam realizadas pesquisas semelhantes em diferentes localidades das cidades 19 . Deve-se destacar que na rede privada, consultórios, clínicas e hospitais veterinários, também ocorre a vacinação antirrábica na rotina de serviço e o conhecimento do número de animais vacinados pela rede privada poderia auxiliar o setor público no dimensionamento real do número de animais vacinados nos municípios 16 .…”