Quantifying transmission of emerging zoonoses: Using mathematical models to maximize the value of surveillance data

Monique R. Ambrose; Adam J. Kucharski; Pierre Formenty; Jean-Jacques Muyembe-Tamfum; Anne W. Rimoin; James O. Lloyd-Smith

give insight into the frequency of spillover and the spatial scale of human-to-human 571 transmission. The district-level model estimates a mean spillover rate of around 0.11 spillover 572 events per locality per year, which corresponds to roughly one spillover event every nine years in 573 each locality. It also estimated that around 70% of human-to-human transmissions occur within a 574 locality. This finding contrasts with the assumption that human-to-human transmission occurs 575 within a locality, which is commonly used to generate transmission clusters, and suggests that 576 estimates generated using that assumption may substantially underestimate the amount of 577 human-to-human transmission occurring in the system. The importance of inter-locality contacts 578 has been reported for the neighboring country of Uganda, where a survey by le Polain de 579