Dynamics of a feline virus with two transmission modes within exponentially growing host populations

Feline panleucopenia virus (FPLV) was introduced in 1977 on Marion Island ( in the southern Indian Ocean) with the aim of eradicating the: cat populati on and provoked a huge decrease in the host population within six years. Th e virus can be transmitted either directly through contacts between infecte d and healthy cats or Indirectly between a healthy cat and the contaminated environment: a specific Feature of the virus is its high rate of survival outside the host. In this paper, a model was designed in order to take thes e two modes of transmission into account. The results showed that a mass-ac tion incidence assumption was more appropriate than a proportionate mixing one in describing the dynamics of direct transmission. Under certain condit ions the virus was able to control the host population at a low density The indirect transmission acted as a reservoir supplying the host population w ith a low but sufficient density of infected individuals which allowed the virus to persist. The dynamics of the infection were more affected by the d emographic parameters of the health) boats than by the: epidemiological one s. Thus, demographic parameters should be precisely measured in field studi es in order to obtain accurate predictions. The predicted results of our mo del were in good agreement with observations.