Ring vaccination campaign reduces the incidence of dog rabies in N’Djaména, Chad

Rabies is a neglected vaccine-preventable zoonotic disease, causing a fatal neurological infection in humans and animals. Domestic dogs can maintain rabies and are the primary reservoir of infection to humans. Recent evidence has suggested that rabies cannot be maintained in urban dog populations and requires repeated introduction of exposed dogs. This study aims to assess the role of human-mediated transport on dog rabies incidence in N’Djaména, Chad. To this end, a ring vaccination campaign around the city was conducted from 2022 to 2023, and incoming dogs were vaccinated. Changes in local dog rabies incidence were used to assess the impact of the intervention with a compartmental model. Analysis and simulations of the model confirmed the role of human-mediated transport as a driver of rabies persistence in N’Djaména. Uncertainty analysis showed that the results were robust despite identifiability issues in separating the importation rate and the transmission rate.