Lack of contact with feline immunodeficiency virus in the Iberian lynx

Abstract

The feline immunodeficiency virus is a lentivirus that infects felids worldwide. It may induce a profound immunodysfunction in domestic cats, while wild felids seem less prone to disease. During routine health check monitoring of the endangered Iberian lynx populations, 465 samples from 311 individuals were tested between 2004 and 2017. All of them tested negative for molecular detection of provirus. Similarly, only one adult male tested positive for FIV antibodies by means of both ELISA and immunoblot. This lack of contact contrasts with the seropositivity detected in other wild felid species, mainly in Africa and the Americas, and confirms that the Iberian Peninsula is not an FIV-endemic area. To prevent a potential disease spreading, the seropositive individual was kept captive for 22 months and remained FIV antibody-positive and antigen-negative during this period. After evaluating potential risks, it was re-introduced to nature. Among other possibilities, this Iberian lynx could have cleared an FIV infection. Moreover, we found 0% qPCR prevalence in 84 feral cats sampled in the area between 2012 and 2016.