Identification of risk factors for rabies exposure and access to post-exposure prophylaxis in Chad

Rabies remains a global public health problem, with Africa as one of the most affected continents. Endemic transmission in the unvaccinated domestic dog population of developing countries leads to many exposures with subsequent death in humans due to lack of access to existing effective prevention tools. The presented study identifies factors of exposure and rabies risk in Chad on the household and health facility levels and highlights the challenges of access to Post Exposure Prophylaxis (PEP). Data on bite exposure and prevention was collected through a representative cross-sectional survey in rural and urban households and through a continuous bite reporting survey in public health facilities. During the household survey 8000 homes were visited, including 3241 (41%) in urban areas and 4759 (59%) in rural areas. The frequency of dog ownership was similar in both rural and urban areas, with around 24% households owning at least one dog. Knowledge of rabies as a disease transmitted mainly from dogs to humans was generally good, but higher in urban (86%) compared to rural areas (73%). The need for early prevention and medical care after a bite was less well known with 35% of respondents believing that rabies is curable after onset of symptoms and only one in three bite victims seeking help in a health facility. Exposure risk based on bite incidence on the population level was increased for Christian compared to Muslim predominant religious context. During the health facility study, 1540 bite cases were registered, of which 58% originated from urban areas and 42% from rural areas. Demographic characteristics of the health facility data subset matched the household survey data subset for the majority of parameters. Only bites from known animals (same household or from neighbourhood) and bites from animals known to be alive were underrepresented, suggesting that such bites are regarded as less dangerous than bites from unknown animals and animals that died, were killed or disappeared. Since human vaccine was provided free of charge during the study, most victims received PEP (84%). However, not all patients completed treatment, with a higher risk of non-compliance observed in rural areas. Access to vaccine before the study was alarmingly low, with only 8.5% accessing PEP. Despite facilitated collaboration between human health and veterinary services through the project, consultation with veterinary services remained generally low. The observed challenges can inform future rabies control programmes on the national level to effectively increase access to PEP exceeding the expected improved availability of human vaccine through the upcoming GAVI investment.