Molecular detection and genotyping of feline immunodeficiency virus (FIV) in domestic cats from Tehran, Iran.

Abstract

FIV is the etiological agent of a cat disease with features similar to the HIV-induced human AIDS. FIV has negative effects on immune system, leaving the cat vulnerable to many other infections. However, epidemiological studies on FIV are relatively unknown in many parts of Iran. Thus, this study aimed to explore FIV prevalence in DSH client-owned cats in Tehran (capital of Iran) by serologic and molecular-based methods. For this study, 346 cats referring to different veterinary clinics in Tehran were screened in 2025 (January to May) by ELISA for FIV-Ab. Then, seropositive cats were analyzed by RT-PCR. Of those cats, we identified nine seropositive cats and 9 FIVs were genetically characterized using FIV V3-V5 env gene sequences. The FIV prevalence in this study population was low, 2.6 %, as determined by both ELISA and RT-PCR methods. Phylogenetic analysis showed that all FIVs belonged to B subtype/clade. The molecular characterization for the env gene of FIV among Iran's cat population was reported for the first time. A significant diversification of amino acid substitutions was found in the V3-V5 sequences driven by charge-shifting mutations and glycosylation changes whilst core structural residues showed conservation. All the FIV-infected cats had concurrent secondary infections. Only mild anemia and mild hyperglobulinemia were found among the few FIV-positive cats, so there was not sufficient data to determine any other consistent hematological or biochemical abnormalities in the cats that tested FIV-positive. Altogether, this study suggests that intensive surveillance and effective prevention strategies are required to determine the prevalence of FIV genotypes in Iran and control continuous infections with FIVs.