Canine-rabies was endemic pre-urbanisation, yet little is known about how it persists in small populations of dogs typically seen in rural and remote regions. Our objectives were to simulate rabies outbreaks in such populations (50-90 dogs) using a network-based model, and investigate the influence of rabies-induced behavioural changes. Such changes - increased bite frequency and either roaming or paralysis that increased the number or duration of contacts, respectively - were essential for disease propagation. Spread occurred in approximately 50% of model simulations and in these, very low case rates (2.0-2.6 cases/month) over long durations (95% range 20-473 days) were predicted. Consequently, disease detection is a challenge, risking human infection and spread to other communities via dog movements. Even with 70% pre-emptive vaccination, spread occurred in >30% of model simulations (in these, median case rate was 1.5/month with 95% range of 15-275 days duration). We conclude that the social disruption caused by rabies-induced behavioural change is the key to explaining how rabies persists in small populations of dogs. We predict that vaccination of substantially greater than the recommended 70% of dog populations is required to prevent rabies emergence in currently free rural areas.
Brookes, V., Durr, S., & Ward, M. P. (2019). Rabies-induced behavioural changes are key to rabies persistence in dog populations: Investigation using a network-based model. PLoS Neglected Tropical Diseases, 13(9), 1-19. [e0007739]. https://doi.org/10.1101/554451