Background: The Feline Immunodeficiency Virus (FIV) causes a lifelong infection in domestic cats being endemic worldwide. FIV has a relatively high evolutionary rate which interferes with vaccination and molecular diagnostic tools.Hypothesis/
Objectives: This study aimed to characterize and evaluate the genetic diversity of FIV in mainland Portugal and Azores, Europe.Animals: This study included 54 urban and rural stray cats from mainland Portugal, and 8 from São Miguel Island, Azores, that tested positive for FIV.
Methods: Samples were obtained between 2009 and 2022. A total of sixty-two FIV positive blood samples were submitted to PCR and Sanger sequencing of the V3-V5 region (previously submitted to Genbank). A phylogenetic analysis was conducted using Mega version 7.
Results: The resulting phylogenetic tree displayed an increasing genetic diversity of FIV subtype B, mainly due to the inclusion of FIV sequences from the Azores islands. A new phylogenetic cluster including new continental Portuguese sequences was also identified, and named subtype F.Conclusions and clinical importance: To our knowledge, this is the first study considering FIV isolates from the Azores Islands besides continental Portugal confirming regional genetic diversity. Updated genetic data is key to determine which FIV subtypes are predominant and for the development of accurate molecular diagnostic methods for the screening and monitoring of cats infected by FIV, particularly in their first 6 months of live and on very rare occasions of later stages of FIV infection where antibodies levels are too low to be detected.
