Molecular Surveillance and Genotypic Distribution of Rotavirus A, Norovirus GI and GII in Bangkok Wastewater Treatment Plants During COVID-19 Phase in 2023, Thailand

Abstract

The presence of multiple viral genotypes of rotavirus A (RAV) and norovirus (NV) circulating among human population and environment is of particular concern to global public health. Hence, the viral prevalence and genetic diversity presented in influent wastewater from Bangkok wastewater treatment plants (WWTPs) was investigated. A total of 89 influent wastewater samples were collected by composite sampling from 10 Bangkok WWTPs between January and May 2023. The wastewater samples were concentrated and extracted for the total nucleic acid. Purified total viral RNA was subjected for cDNA synthesis, conventional PCR for detecting RAV, NV GI and GII, and DNA sequencing. The detection rate of RAV, NV GI and GII was 13.5% (12/89), 94.4% (84/89) and 89.9% (80/89), respectively. Co-detection was observed accounting 74.2% (66/89) and 13.5% (12/89) for NV GI + GII and NV GI + GII + RAV, respectively. A total of 76 viral sequences including 11 RAV, 33 NV GI, and 32 NV GII, were obtained and phylogenetically analyzed for viral genotyping. All RAV belonged to genotype G3 (100.0%). The 33 NV GI were identified in four distinct genotypes comprising GI.5 (72.7%), GI.3 (9.1%), GI.4 (9.1%), and GI.6 (9.1%). For NV GII, the genotype GII.17 was the most prevalent, accounting 87.5% followed by GII.2 (6.25%), GII.3 (3.13%), and GII.9 (3.13%). This study demonstrated the presence of RAV and multiple genotypes of NV GI and GII contaminating and co-circulating in community wastewater during COVID-19 situation in Bangkok. Viral dynamics between human population and environment raised potentially concerns for epidemiological patterns, affecting human health and safety.