Viruses of the Serengeti: patterns of infection and mortality in African lions

1. We present data on the temporal dynamics of six viruses that infect lion s (Panthera lee) in the Serengeti National Park and Ngorongoro Crater, Tanz ania, These populations have been studied continuously for the past 30 year s, and previous research has documented their seroprevalence for feline her pesvirus, feline immunodeficiency virus (FIV), feline calicivirus, feline p arvovirus, feline coronavirus and canine distemper virus (CDV), A seventh v irus, feline leukaemia virus (FeLV), was absent from these animals, 2. Comprehensive analysis reveals that feline herpesvirus and FIV were cons istently prevalent at high levels, indicating that they were endemic in the host populations. Feline calici-, parvo- and coronavirus, and CDV repeated ly showed a pattern of seroprevalence that was indicative of discrete disea se epidemics: a brief period of high exposure for each virus was followed b y declining seroprevalence. 3. The timing of viral invasion suggests that different epidemic viruses ar e associated with different minimum threshold densities of susceptible host s, Furthermore, the proportion of susceptibles that became infected during disease outbreaks was positively correlated with the number of susceptible hosts at the beginning of each outbreak. 4. Examination of the relationship between disease outbreaks and host fitne ss suggest that these viruses do not affect birth and death rates in lions, with the exception of the 1994 outbreak of canine distemper virus. Althoug h the endemic viruses (FHV and FIV) were too prevalent to measure precise h ealth effects, there was no evidence that FIV infection reduced host longev ity.