Circulation of arctic canine distemper virus in diarrheic dogs in Iran: molecular detection and phylogenetic characterization

Canine distemper virus (CDV) is a pathogen that causes systemic infection in dogs and wildlife. Among the highly variable regions in the genome of the virus, the H gene is commonly sequenced for phylogenetic studies. The aim of the present study was to screen for the presence of CDV infection in dogs in Iran and to identify the genotype of the virus. Seventy-five dogs with gastrointestinal symptoms were screened via an immunochromatographic test. Fifty of them were positive. CDV was isolated from rectal swabs, and PCR was performed. The top 10 positive cases were subsequently selected for sequencing. Phylogenetic analyses were subsequently conducted. Among the 75 dogs analyzed, 50 (66.7%) dogs were found to be infected with CDV via rapid tests. All 10 sequenced isolates were from the Arctic lineage, forming a monophyletic cluster. Our sequences closely clustered with some European strains. Some nucleotide variations were observed. The present study reports the presence of Arctic-like CDV strains in diarrheic dogs in Tehran. Ongoing molecular surveillance will help in assessing any alterations in genetic diversity and vaccine efficacy. Future studies in other regions in Iran would be helpful.