Understanding reservoirs of multi-host pathogens: A One Health approach to rabies in Tanzania

Rabies virus is a multi-host zoonotic pathogen that is endemic across large parts of sub-Saharan Africa. This case study reports a One Health approach to rabies in Tanzania which highlights the value of multi-sectoral collaboration and illustrates the importance of understanding the reservoir dynamics of multi-host pathogens when targeting interventions. As part of our research we have established contact tracing for rabies in Tanzania. This involves identifying patients presenting with animal-bite injuries and investigating the animals responsible for the bites. Through contact tracing we identify the owners of biting animals, ascertain the rabies status of these animals, and identify additional bite victims who have not presented to healthcare centres. Domestic dog vaccination is a key component of current rabies control programmes as domestic dogs are responsible for most human rabies exposures across Africa. However, in some areas rabies transmission also occurs within wildlife populations. For example, in the Lindi and Mtwara regions of southern Tanzania, jackals represent an unusually high proportion of animal rabies cases. Maintenance of rabies virus within wildlife populations can have implications for control strategies centred around domestic dog vaccination. Throughout this case study we illustrate the use of multiple data sources to identify the role of domestic dogs and wildlife in rabies transmission in the Lindi and Mtwara regions of southern Tanzania and compare this to the island of Pemba where domestic dog cases dominate. We highlight how domestic dog vaccination plays a vital role in controlling rabies in these two areas with very different disease ecology.