Vet World   Vol.18   December-2025  Article - 36 

First genomic evidence and molecular epidemiology of porcine bufavirus in Myanmar: Whole-genome characterization, phylogenetic insights, and potential zoonotic implications

Hnin Wai Phyu^1,2 , Kamonpan Charoenkul^1,2 , Chanakarn Nasamran^1,2 , Kitikhun Udom^1,2 , Eaint Min Phyu³ , Yu Nandi Thaw³ , Supassama Chaiyawong^1,2 , Thant Nyi Lin⁴ , Min Thein Maw⁵ , and Alongkorn Amonsin^1,2

Background and Aim: Porcine bufavirus (PBuV) is an emerging enteric parvovirus increasingly reported in swine populations worldwide, but its epidemiological and genomic characteristics remain poorly understood in Southeast Asia. This study aimed to conduct a cross-sectional survey to determine the occurrence of PBuV in pig farms in Myanmar and to genetically characterize circulating Myanmar-PBuVs using whole-genome sequencing (WGS). 

Materials and Methods: Between January and September 2023, 445 rectal swab samples were collected from pigs of various age groups and clinical statuses across 19 pig farms in the Yangon and Nay Pyi Taw Regions. Samples were screened using nested polymerase chain reaction (PCR) targeting the nonstructural protein 1 (NS1) gene. Seven PCR-positive samples were selected for WGS based on farm location, animal age, collection time, and amplicon quality. Phylogenetic analyses of whole genomes and NS1, viral protein 1 (VP1), and viral protein 2 (VP2) genes were performed using maximum–likelihood methods. Nucleotide and amino acid identities, conserved motifs, and unique mutations were assessed to determine genetic relationships with global PBuV and bufavirus (BuV) lineages. 

Results: PBuV positivity was 15.06% (67/445; 95% confidence interval: 11.9–18.7), with detection in both diarrheic and healthy pigs. Fattening pigs exhibited the highest positivity (36.55%), and PBuV occurrence was significantly associated with winter months (p < 0.05). Seven Myanmar-PBuVs were successfully sequenced and clustered within the PBuV clade, showing close genetic relatedness to Austrian and Chinese PBuVs. Myanmar-PBuVs shared 91.81%–100% whole-genome nucleotide identity, with substantially lower identity (48%–63%) to BuVs from humans, dogs (Canis lupus familiaris), bats (various species), and rats (Rattus spp.). Conserved NS1, VP1, and VP2 motifs were preserved; however, unique amino acid insertions in NS1 (notably in CU34347) and several VP2 substitutions suggested potential region-specific evolution. 

Conclusion: This study provides the first genomic evidence of PBuV circulation in Myanmar and expands the global PBuV sequence database. The high detection in fattening pigs, seasonal trends, and phylogenetic proximity to European and Chinese strains highlight possible transboundary introduction pathways. Genetic similarities between Myanmar-PBuVs and human BuV in VP1/VP2 underscore the importance of One Health surveillance. Broader-scale longitudinal studies are needed to clarify PBuV evolution, disease association, and zoonotic potential. 

Keywords: Emerging swine viruses, Molecular detection, Myanmar pig farms, One Health surveillance, Phylogenetic analysis, Porcine bufavirus, Whole-genome characterization, Zoonotic potential.

How to cite this article: Phyu, H. W., Charoenkul, K., Nasamran, C., Udom, K., Phyu, E. M., Thaw, Y. N., Chaiyawong, S., Lin, T. N., Maw, M. T., and Amonsin, A. (2025) First genomic evidence and molecular epidemiology of porcine bufavirus in Myanmar: Whole-genome characterization, phylogenetic insights, and potential zoonotic implications, Veterinary World, 18(12): 4157–4171.

Received: 15-07-2025   Accepted: 03-12-2025   Published online: 31-12-2025

Corresponding author: Alongkorn Amonsin    E-mail: alongkorn.a@chula.ac.th

DOI: 10.14202/vetworld.2025.4157-4171

Copyright: Phyu, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.