  We study an epidemic propagation between $M$ population centra. The novelty
of the model is in analyzing the migration of host (remaining in the same
centre) and guest (migrated to another centre) populations separately. Even in
the simplest case $M=2$, this modification is justified because it gives a more
realistic description of migration processes. This becomes evident in a purely
migration model with vanishing epidemic parameters. It is important to account
for a certain number of guest susceptible present in non-host cenrta because
these susceptible may be infected and return to the host node as infectives.
The flux of such infectives is not negligible and is comparable with the flux
of host infectives migrated to other centra, because the return rate of a guest
individual will, by nature, tend to be high. It is shown that taking account of
both fluxes of infectives noticeably increases the speed of epidemic spread in
a 1D lattice of identical SIR centra.
