Research overview: progressive versus regressive feline leukemia virus infection in wildlife

Feline leukemia virus infections range from progressive, with persistent viremia and high mortality, to regressive, where the host contains the virus and may clear detectable antigen. This overview surveys how these outcomes complicate disease assessment in wild felids, where a single snapshot test may misclassify an animal’s status and prognosis. It covers the immunology underlying containment versus disease, the use of molecular tools to detect latent proviral DNA, and the implications for surveillance and management of endangered populations like the Iberian lynx. The synthesis explains why understanding infection stage matters for predicting mortality, deciding on removal versus monitoring, and interpreting prevalence. It aims to give readers insight into why FeLV epidemiology in wildlife is more nuanced than a simple positive-or-negative result.