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Professor Gertjan Medema


Citation for Professor Gertjan Medema



Professor Gertjan Medema from the KWR Water Research Institute is awarded the Lee Kuan Yew Water Prize for 2024 for his significant contributions in the field of wastewater-based epidemiology (WBE in short). His timely research breakthrough has global impact and enabled the use of wastewater surveillance during the COVID-19 pandemic to fight the spread of the virus.

Professor Medema is a renowned microbiologist and an expert in water quality and health, particularly known for his extensive research on the detection and control of waterborne pathogens. His work has significantly contributed to the world’s understanding of how waterborne pathogens are transmitted through water and how such transmission can be prevented. During the COVID-19 pandemic, his expertise was especially relevant as concerns about the presence and transmission of SARS-CoV-2, the virus responsible for COVID-19, in water systems emerged. At the onset of COVID-19 in early 2020, Professor Medema and his team were the first to detect the presence of SARS-CoV-2 in wastewater in the Netherlands, even before cases were officially reported in certain cities. Recognising the importance of early detection and surveillance, he swiftly pivoted his team’s research to address the urgent need to monitor the spread of the virus.

With a career spanning from the 1990s, Professor Medema's expertise has been foundational in establishing wastewater-based epidemiology as a tool for public health surveillance. His contributions were evident and received worldwide attention, with his first publication on WBE garnering over 1,400 citations and more than 34,000 views between 2020 and 2023.

Professor Medema's research demonstrated that monitoring wastewater for genetic markers of SARS-CoV-2 could serve as an early warning system for COVID-19 outbreaks. By detecting the virus in wastewater, even before cases are reported through clinical testing, WBE can provide valuable insights into the prevalence of the virus in a community. This approach has proven to be a cost-effective and non-invasive method for tracking the spread of the disease, and Professor Medema's contributions have been pivotal in its global adoption. There are currently more than 4,000 sites in 72 countries, including Singapore, that have adopted wastewater surveillance of SARS-CoV-2, and Professor Medema himself was connected to about 30% of these programmes directly.

Singapore benefitted from Professor Medema’s work through the testing of wastewater for SARS-CoV-2 shortly after he discovered its potential as an epidemiological tool and early warning system for outbreaks. As the COVID-19 pandemic unfolded in 2020, NEA’s Environmental Health Institute (EHI), together with PUB, Home Team Science and Technology Agency (HTX), and other collaborators from the local universities and research institutes embarked on the WBE process quickly. As a result, Singapore has been able to ramp up its testing to hundreds of sites, including workers’ dormitories, residential areas, town centres, student hostels, and welfare homes.

Professor Medema's research extends beyond the scientific community to inform public health policy and decision-making. By providing data on the occurrence and trend of SARS-CoV-2 in wastewater, his work has helped public health authorities to better understand the dynamics of the pandemic, assess the effectiveness of intervention measures, and allocate resources more efficiently. This has been particularly valuable in areas with limited access to clinical testing or where asymptomatic transmission is a concern.

Professor Medema has been actively involved in international collaborations, sharing his expertise and findings with the global scientific community. He made significant contributions to the development of international guidelines and best practices for wastewater surveillance, including those set by the World Health Organisation (WHO) and European Union (EU), ensuring that the knowledge gained from his research is disseminated and applied effectively. His leadership in this area has helped to establish a network of researchers and practitioners dedicated to using WBE as a tool for public health surveillance.

Dedicated to advancing the science of waterborne pathogens, Professor Medema’s swift response to the challenges posed by COVID-19 epitomises his commitment to public health and safety. His work will undoubtedly continue to influence the field and contribute to the global fight against the pandemic and future public health threats beyond COVID-19.

The Lee Kuan Yew Water Prize 2024 is bestowed on Professor Gertjan Medema for his groundbreaking efforts in wastewater epidemiology and surveillance to combat the COVID-19 pandemic, which supported public health interventions and policies benefiting millions of people worldwide.

About Professor Gertjan Medema

Professor Gertjan Medema, a distinguished Dutch scientist, has been a Principal Microbiologist at KWR Water Research Institute since 1996. He was awarded for his significant global impact in the field of wastewater-based epidemiology (WBE), and his timely research breakthrough that enabled him to spearhead the use of wastewater surveillance in response to the COVID-19 pandemic.

Professor Medema holds a part-time chair in Water & Health at Delft University of Technology (Section of Sanitary Engineering) since 2009. From 2018 to 2022, he served as the Distinguished Hannah Visiting Professor on Water & Health at Michigan State University.

His research revolves around understanding the transmission of waterborne pathogens and antimicrobial resistance via water systems. His work includes developing methods for detecting and tracing pathogens such as viruses, bacteria, and parasites in water.

He conducts Quantitative Microbial Risk Assessment (QMRA), examining health effects related to water systems. Professor Medema initiated research on sewage surveillance of SARS-CoV-2 during the COVID-19 pandemic, inspiring similar programs worldwide. He also led the epidemiological re-investigation of the Legionella outbreak in Flint, Michigan and proposed recommendations to improve Legionella prevention and response.

Professor Medema advises the World Health Organization (WHO) on microbiological drinking water guidelines and QMRA since 1991, as well as SARS, Water, Sanitation & Hygiene (WASH) and wastewater surveillance. He also advises the European Commission on the EU Drinking Water Directives and water reuse guidelines.

Professor Medema has been the coordinator and collaborator in several European research projects and more than 50 national research projects on the microbial safety of drinking water as part of the cooperative research program of the Dutch water supply utility research and international research.

His impact on science is evidenced by publication records of 168 publications and more than 7,000 citations worldwide.