“…the disappearance of the parasite when entering the target cell is neglected) and ϕ(x) = Λ − µ x x, this condition is automatically satisfied, hence R 0 > 1 is a necessary and sufficient (NSC) for the GAS of the infected equilibrium. In Section 6 we apply the preceding results to models studied by Nelson and Perelson in [15]. We come across the results of these authors and improve some of them.…”