Understanding multi-host pathogen maintenance and transmission dynamics is critical for\ud disease control. However, transmission dynamics remain enigmatic largely because they are\ud difficult to observe directly, particularly in wildlife. Here, we investigate the transmission\ud dynamics of canine parvovirus (CPV) using state-space modelling of 20-years of CPV serology\ud data from domestic dogs and African lions in the Serengeti ecosystem. We show that, although\ud vaccination reduces the probability of infection in dogs, and despite indirect enhancement of\ud population seropositivity as a result of vaccine shedding, the vaccination coverage achieved\ud has been insufficient to prevent CPV from becoming widespread. CPV is maintained by the\ud dog population and has become endemic with ~3.5-year cycles and prevalence reaching ~80%.\ud While the estimated prevalence in lions is lower, peaks of infection consistently follow those\ud in dogs. Dogs exposed to CPV are also more likely to become infected with a second multihost\ud pathogen, canine distemper virus. However, vaccination can weaken this coupling raising\ud questions about the value of monovalent versus polyvalent vaccines against these two\ud pathogens. Our findings highlight the need to consider both pathogen- and host-level\ud community interactions when seeking to understand the dynamics of multi-host pathogens and\ud their implications for conservation, disease surveillance and control programmes.
