Measuring SARS-CoV-2 RNA in Bangkok wastewater treatment plants and estimating infected population after fully opening the country in 2023, Thailand

• Published in: Scientific reports Vol. 15; no. 1; pp. 9663 - 14
• Main Authors: Saita, Thanchira, Thitanuwat, Bussarakam, Niyomdecha, Nattamon, Prasertsopon, Jarunee, Lerdsamran, Hatairat, Puthavathana, Pilaipan, Noisumdaeng, Pirom
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.03.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326; 631/326/596/4130; 692/699; 692/699/255/2514; 704/172; Correlation coefficient; COVID-19; COVID-19 - epidemiology; COVID-19 - virology; Effluents; Epidemiology; Humanities and Social Sciences; Humans; multidisciplinary; Population studies; Ribonucleic acid; RNA; RNA, Viral - analysis; RNA, Viral - genetics; RNA, Viral - isolation & purification; SARS-CoV-2 - genetics; SARS-CoV-2 - isolation & purification; Science; Science (multidisciplinary); Severe acute respiratory syndrome coronavirus 2; Spatial analysis; Statistical analysis; Thailand - epidemiology; Wastewater - virology; Wastewater treatment; Wastewater treatment plants; Water treatment; Thailand; Bangkok Thailand
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-025-94938-7

Wastewater-based epidemiology (WBE) has been employed for monitoring the presence of SARS-CoV-2 infected population. Herein, the study aims to apply the WBE for surveillance and monitoring SARS-CoV-2 in Bangkok, where the highest official covid-19 cases reported in Thailand, during the fully opening for international tourists in early 2023. A total of 200 wastewater samples (100 influent and 100 effluent samples) were collected from 10 wastewater treatment plants (WWTPs) during January–May 2023. SARS-CoV-2 RNA was detected by real time qRT-PCR with accounting for 51% (102/200). Of these, 88% (88/100) and 14% (14/100) were detected in influent and effluent samples, respectively. The SARS-CoV-2 RNA concentration was detected in ranged of 4.76 × 10 2 –1.48 × 10 5 copies/L. The amount of SARS-CoV-2 RNA has increased approximately 4 times from the lag phase (January–March) to the log phase (April–May). Spearman’s correlation coefficient revealed that correlation between estimated infected population and weekly reported cases was statistically significant ( p -value = 0.017). SARS-CoV-2 RNA in influent had a statistically significant relationship with weekly reported cases ( r  = 0.481, p -value < 0.001). Lag time analysis revealed early warning 1–3 weeks before rising covid-19 cases observed. GIS was applied for spatial-temporal analysis at the province level, suggesting real time dashboard should be further developed.