Abstract

Viral transmission between host species can harm public health, conservation efforts, and the global economy. In 1998-1999 a novel paramyxovirus, now known as Nipah virus, emerged in peninsular Malaysia and Singapore, killing 105 people and devastating the commercial pig farming industry. I will describe a multinational, collaborative investigation of the factors that led to this widespread epidemic of Nipah virus encephalitis, particularly focusing on my work on the dynamics of emergence. I will then show how the results from this case study can be generalized to describe a phenomenon I call “epidemic enhancement,” whereby repeated viral introduction into a novel host population can produce longer and larger epidemics than observed upon initial introduction. I will use simple dynamical models to show that this is a realistic scenario within the parameter ranges of many common infectious diseases. Finally, I will give a broad overview of how models have been used to understand zoonotic processes and discuss important gaps in our current understanding, with implications for where to focus future efforts.