Environmental surveillance of SARS-CoV-2 in municipal wastewater to monitor COVID-19 status in urban clusters in Malaysia

Abstract

Wastewater monitoring for SARS-CoV-2 has attracted considerable attention worldwide to complement the existing clinical-based surveillance system. In this study, we report our first successful attempt to prove the circulation of SARS-CoV-2 genes in Malaysian urban wastewater. A total of 18 wastewater samples were obtained from a regional sewage treatment plant that received municipal sewage between February 2021 and May 2021. Using the quantitative PCR assay targeting the E and RdRp genes of SARS-CoV-2, we confirmed that both genes were detected in the raw sewage, while no viral RNA was found in the treated sewage. We were also able to show that the trend of COVID-19 cases in Kuala Lumpur and Selangor was related to the changes in SARS-CoV-2 RNA levels in the wastewater samples. Overall, our study highlights that monitoring wastewater for SARS-CoV-2 should help local health professionals to obtain additional information on the rapid and silent circulation of infectious agents in communities at the regional level.

Keywords: COVID-19; Malaysia; Municipal; SARS-CoV-2 RNA; Wastewater.

Fig. 1

A representation of the geographic map shows the wastewater sampling site used in this study from a municipal wastewater treatment plant (WWTP) in Kuala Lumpur, Malaysia

Fig. 2

Detection of SARS-CoV-2 RNA in municipal wastewater in relation to COVID-19 cases reported in Kuala Lumpur (KL). a The concentration of SARS-CoV-2 RNA based on E gene-based RT-qPCR assay using influent samples. Error bars indicate standard error of the mean for at least two technical replicates. b The number of daily COVID-19 cases reported from the Ministry of Health Malaysia (Kementerian Kesihatan Malaysia 2022)