Co-circulation and genetic characterization of genotype I and II feline bocavirus strains in domestic cats from Northern Vietnam.

Abstract

Background and aim: Feline bocavirus (FBoV), a member of the Parvoviridae family, has been implicated in gastrointestinal and respiratory conditions in domestic cats. Despite increasing global recognition, the molecular epidemiology of FBoV in Vietnamese animal populations remains largely unexplored. This study aimed to detect and genetically characterize FBoV strains circulating among domestic cats in Northern Vietnam to better understand their genotypic diversity and potential clinical relevance.

Materials and methods: A total of 166 fecal samples were collected from domestic cats of varying age, sex, and clinical status across four provinces in Northern Vietnam between 2022 and 2023. DNA was extracted and screened for FBoV using conventional polymerase chain reaction targeting the non-structural (NS)-1 gene. Positive samples were subjected to Sanger sequencing, and partial NS1 sequences were analyzed using MEGA X for phylogenetic inference. Recombination analysis was performed using RDP 4.0, and statistical significance was assessed using Fisher's exact test.

Results: FBoV DNA was detected in 4 of 166 samples (2.41%), including one from a diarrheic cat and three from healthy cats. Phylogenetic analysis of the partial NS1 gene revealed that three strains belonged to genotype I and one to genotype II, all showing close genetic similarity to Chinese strains. Nucleotide identities among Vietnamese strains ranged from 64.68% to 99.57%. No recombination events were observed among the detected strains. FBoV was detected across age groups and both sexes, without significant associations. Co-infections with other enteric viruses (feline coronavirus, feline panleukopenia virus, feline astrovirus, and feline kobuvirus) were not observed in the FBoV-positive samples.

Conclusion: This study provides the first molecular evidence of co-circulating FBoV genotypes I and II in domestic cats in Vietnam, indicating viral genetic diversity and suggesting possible regional transmission routes linked to neighboring countries. While FBoV was present in both symptomatic and asymptomatic cats, its clinical significance remains inconclusive. The findings underscore the need for expanded surveillance, complete genome analyses, and investigation into FBoV's pathogenic potential and co-infection dynamics in the feline population. These data will be instrumental in shaping future diagnostic and control strategies for feline viral enteritis in Vietnam.