Epidemiology and genetic diversity of group A rotaviruses in pre-vaccination period in Thailand, 2018-2019.

Abstract

Group A rotaviruses (RVAs) are the major viruses that cause acute gastroenteritis in young children worldwide. The objective of this study was to investigate the prevalence and genotype diversity of RVAs circulating in children with acute gastroenteritis in Thailand before the implementation of RVA vaccine in the childhood immunization programme. A total of 1170 stool specimens were obtained in 2018-2019 from children admitted to hospitals with diarrhea and screened for RVAs by nested RT-PCR. The RVA genotypes were determined by multiplex-PCR or nucleotide sequencing and phylogenetic analysis. Out of 1170 stool specimens, 209 (17.9%) were positive for RVAs. The RVA genotype G9P[8] (24.4%) was the most dominant genotype, followed by G3P[8] (22.9%), G8P[8] (22.0%), G1P[8] (16.7%), G2P[4] (6.7%), G1P[6] (2.3%), G1P[4] (1.0%), G3P[4] (1.0%), G9P[4] (1.0%), mixed-infections of G1P[4]\u202f+\u202fG1P[8] (1.0%), and GXP[8] (0.5%). Moreover, the uncommon RVA strain G3P[10] (0.5%) bearing bat-like RVA was detected. This study reveals the prevalence and genetic diversity of RVA genotypes in children with acute gastroenteritis in Thailand. The knowledge obtained from this study is helpful for understanding the epidemiology of rotavirus before the introduction of RVA vaccine in Thailand. In addition, the emergence of uncommon G-P combination RVA strain G3P[10] provides an evidence for interspecies transmission of human and animal rotaviruses.