  This paper presents a new view of household epidemic models, where the
interaction between the households is of mean field type. We thus obtain in the
limit of infinitely many households a nonlinear Markov process solution of a
McKean - Vlasov type Poisson driven SDE, and a propagation of chaos result. We
also define a basic reproduction number R0, and show that if R0>1, then the
nonlinear Markov process has a unique non trivial ergodic invariant probability
measure, whereas if R0<=1, it converges to 0 as t tends to infinity.
