Risk Factors and Protective Immunity Against Rabies in Unvaccinated Butchers Working at Dog Slaughterhouses in Northern Vietnam

Abstract

Vietnam is a rabies-endemic country where eating dog meat is customary. However, the risks of rabies transmission to dog slaughtering and processing workers have not been identified. This study aimed to determine the rabies neutralizing antibody (NTA) and risk factors in dog slaughterers to propose appropriate intervention methods for this occupational group. In 2016, a cross-sectional study on NTA against rabies virus and related factors was conducted among 406 professional dog slaughterers in Vietnam. The participants were interviewed using a structured questionnaire, and their sera were tested for rabies NTA by a rapid focus fluorescence inhibition test. Statistical algorithms were used to analyze the data. The results showed that most of the professional dog butchers (344/406 subjects, 84.7%) had no rabies NTA. Interestingly, 7.8% (29/373) had NTA without a rabies vaccination history. Over 5 years of experience as a dog butcher was positively associated with the presence of NTA in unvaccinated individuals (OR = 6.16, P = 0.001). The NTA in vaccinated butchers was present in higher titer and for longer persistence to those of other previously reported professionals, which is possibly as a result of multiple exposures to low levels of rabies virus antigens during dog slaughtering. Our study demonstrated that professional dog butchers in Vietnam are at a high risk of rabies virus infection, apart from those with common bite experiences. In countries where dog meat consumption is customary, rabies control and prevention activities should focus on safety during dog trading and slaughtering.

Rabies in Southeast Asia: a systematic review of its incidence, risk factors and mortality

“…Dog butchers in Vietnam were at high risk of rabies virus infection 31. The study found that 28.3% of butchers were at risk of rabies exposure due to the slaughtering of sick dogs and getting bites, scratches or knife cuts.…”

“…Dog butchers in Vietnam were at high risk of rabies virus infection. 31 The study found that 28.3% of butchers were at risk of rabies exposure due to the slaughtering of sick dogs and getting bites, scratches or knife cuts. Of 406 participants, 8.6% had sufficient levels of rabies neutralising antibody for protection and only 8.1% were vaccinated.…”

“…A study reported that 91.9% of professional dog butchers in Vietnam were not vaccinated against rabies, which may be because of fear of the side effects of the rabies vaccine, inability to afford vaccination and incorrect knowledge of rabies prevention. 31 …”

“…Professional dog butchers in northern Vietnam are at a high risk of rabies virus infection due to exposure during the slaughtering process from the handling of sick or dead dogs and getting bitten, scratched or cut with knives. A study reported that 91.9% of professional dog butchers in Vietnam were not vaccinated against rabies, which may be because of fear of the side effects of the rabies vaccine, inability to afford vaccination and incorrect knowledge of rabies prevention 31…”

Seroprevalence of Rabies Virus in Dogs in the Mekong Delta, Viet Nam

“…The genetic characterization of rabies recovery from Burkino-Faso and Viet Nam demonstrated that the isolates exhibited similarities with those obtained from Mauritania and China, respectively (De Benedictis et al 2010;Nguyen et al 2011). Another example, dog slaughterhouses are considered as hotspot of rabies and dog butchers become at a high risk of rabies virus infection (Nguyen et al 2021). This suggests that rabies has the potential to spread across borders, underscoring the importance of dog trading and slaughtering in the epidemiology of rabies and warranting further concern.…”