A persistent infection means that the infection stays in the body for a long time or keeps coming back, even after treatment or the body's natural defense mechanisms have tried to get rid of it. Full definition
If the cat's immune response failed to initially fight the virus, a later stage characterized by persistent infection of the bone marrow and other tissue is developed. (feline-nutrition.org)
The world is saturated in germs, and sooner or later the ones that can maintain persistent infections take up residence in all of us. (perfecthealthdiet.com)
Others may have persistent infections varying in severity, some of which could be fatal over time. (salmonbrookvets.com)