HKUMed MFN v26i1

Feature Man and machine come together in the Japanese cartoon character AstroBoy, a part human-part robot superhero. Fittingly, AstroBoy also adorns the lab coat of Professor Zhang Tong of the Environmental Microbiome Engineering and Biotechnology Laboratory of the Department of Civil Engineering, whose work fuses engineering solutions to human health concerns. Professor Zhang worked with School of Public Health (SPH) scholars to devise a method of using sewage samples to detect hidden COVID-19 cases – work that has become a key plank in the government’s efforts to contain outbreaks and won the Gold Medal award at the 2021 Inventions Geneva Evaluation Days. ‘At the beginning, even we did not have much confidence that it would be effective or that we could do this on a large scale. Things have developed so fast,’ he said. The project started in April last year when Professor Zhang, an expert in wastewater microorganisms and treatment, was approached by Hong Kong’s Drainage Services Department about detecting SARS-CoV-2 in sewage to protect their staff. He brought in the School of Public Health (SPH), with which he had collaborated on another project investigating antimicrobial resistant bugs in hospital wastewater. ‘We know the sewage, Astro-Nomical Achievements The Gold Medal award winners at the 2021 Inventions Geneva Evaluation Days talk about their fruitful collaboration in developing the sewage COVID-19 virus surveillance system. and they know the epidemiology,’ he said. Professor Zhang’s laboratory began to collect samples from community sewage, condense the samples, and extract RNA with the team of Dr Hein M Tun of SPH, a public health researcher. This was then forwarded to Professor Leo Poon Lit-man ’s team in the same school to discern whether SARS-CoV-2 was present in the samples. By summer, the early warning potential of this approach began to bear fruit: sewage samples from two buildings tested positive for the virus even though the buildings had no reported cases (multiple cases were later detected). ‘This was when we realised the assays were working,’ Professor Poon said. ‘We did this for every sample, and every sample was huge,’ Dr Tun said. The technique enabled the HKU team to find the proverbial needle in a haystack and led to a larger, one-year project funded by the Health and Medical Research Fund, under which daily samples have been collected from 26 stationary sites since last October, Professor Gabriel Leung , Dean of Faculty of Medicine, and Professor Malik Peiris from SPH. In mid-November, that project proved its worth when the HKU team began to detect SARS-CoV-2 virus in sewage samples taken from different areas of Hong Kong – days before COVID-19 cases were confirmed in those areas. 18