Prevalence and genetic diversity of porcine rotavirus A from diarrheic piglets in Northern Thailand.

BACKGROUND

Rotavirus A (RVA) is an important pathogen causing acute viral gastroenteritis in young children and various animals. RVA is also recognized as a common cause of gastroenteritis in piglets. Epidemiological studies of porcine RVA (PoRVA) conducted in different settings worldwide reported that the prevalence of PoRVA infection ranged from 9.4% to 74.0% with the predominance of G4P[6], G4P[7], and G5P[7] genotypes. In Thailand, long-term epidemiological surveillance of PoRVA infection is limited. Continuous monitoring of PoRVA infection is required to gain a better understanding the prevalence and evolution of PoRVA. In this study, the prevalence and genetic diversity of PoRVA were investigated by screening of 1,260 stool samples collected from 0 to 5-week-old piglets with acute diarrhea during 2016 to 2023 by using real-time RT-PCR. The G- and P-genotypes of RVA were identified by characterization of the partial VP7 and VP4 genes by using multiplex-PCR, nucleotide sequencing, and phylogenetic analysis.

RESULTS

A total of 303 out of 1,260 (24.0%) samples were positive for PoRVA. Overall, the G5P[23] (28.7%) and G4P[23] (28.4%) were detected as the co-predominant PoRVA genotypes, followed by G5P[13] (9.9%), G3P[23] (9.6%), G9P[23] (8.2%), G4P[13] (7.9%), G9P[13] (3.3%), G3P[13] (1.7%), G4P[6] (1.7%), and G2P[23] (0.3%) genotypes. Additionally, a rare G2P[27] (0.3%) genotype re-emerged approximately 22 years after the initial detection in 2000 in Chiang Mai, Thailand.

CONCLUSION

Our results revealed the prevalence of wide variety of PoRVA genotypes circulating in piglets with acute diarrhea in Thailand over a study period of seven years. Of these, G5P[23] and G4P[23] emerged as the most predominant genotypes, which were substantially different from previous reports in the same geographical area. The findings offer valuable contribution to a better understanding of molecular epidemiology and evolution of PoRVA in piglets with acute diarrhea.