Sewage Surveillance for SARS-CoV-2 Virus

Principal Investigator: Professor Tong ZHANG (Department of Civil Engineering)

This project is showcased in the inaugural exhibition – Engineering for Better Living in Innovation Wing Two

Project information


The sewage testing tool for SARS-CoV-Z virus was invented by an inter-disciplinary team led by Professor Tong Zhang, from the Environmental Microbiome Engineering and Biotechnology Laboratory of the Department of Civil Engineering of the Faculty of Engineering.

Novelty of the Project

Firstly, we invented a two-step separation method and used detections of two gene segments of the SARS—CoV-2 virus. In one case, it enabled the successful detection of one COVID-19 patient out of 56,000 people from their aggregated sewage sample. Secondly, we developed a compact auto-sampler that can be easily mounted underneath the existing sewerage manhole covers to collect the sewage sample automatically, thus minimizing the impacts on ground—level public activities. Thirdly, a territory-wide sewage surveillance system has been well established in Hong Kong through close collaboration between an interdisciplinary research team of environmental microbiology and public health from the University of Hong Kong and the Government of the Hong Kong SAR, including the Environment Bureau, the Food and Health Bureau, the Drainage Services Department and the Environmental Protection Department.

Benefit to the Community

This tool helps track hidden transmission chain in community, and it was successfully implemented to uncover more than 50 hidden COVID-19 cases in local community in Hong Kong by triggering in government compulsory testing. This new invention has now been transferred to commercial labs for routine monitoring of COVlD-19 re—emergence for over five million residents. It now serves as a powerful management tool to fight COVID-19 by providing early warning signals of silent virus transmission with over 200 samples collected every week from 112 stationary monitoring sites that cover 5.3 million people living in the city.

About the Scholar

Professor Zhang is the Chair Professor in Department of Civil Engineering, HKU. His researches focus on the environment-microbiome-health dimenstions, including studies on antibiotics and antibiotic resistance genes, wasterwater-based epidemiology, environmental biotechnology, environmental bioinformatics, and biological wastewater treatment.

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Achievement of the Project
  • Gold Medals at 2021 Inventions Geneva
  • Medal of Honour in 2021 Honours List
  • Chief Executive’s Commendation for Community Service in 2021 Honours List
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