Prof. Gertjan Medema PhD

Principal microbiologist

030-6069653
Gertjan.Medema@kwrwater.nl
06-25032597

PCR methods for legal parameters

In determining the (hygienic) quality of drinking water, use is made of E. coli, intestinal enterococci and bacteria from the coli group (coliforms) as indicator organisms. Culture methods are the standard technique used to establish the presence…

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Effect of manganese on biofilm formation

The aim of this project is to determine how low manganese concentrations in drinking water affect the formation of biofilm in the distribution system. Biofilm in drinking water with and without manganese…

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PATHOCERT- Pathogen Contamination Emergency Response Technologies

What are the waterborne pathogen challenges, and how are they affecting the first responders? How should they react to enhance the resilience of European cities to waterborne threats…

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High-throughput qPCR

Ever-faster, 'high-throughput qPCR' methods are becoming available for the simultaneous detection and identification of large quantities of genes. This study looks at how a number of promising methods compare with the qPCR methods already being used by…

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KWR to advise the State of Michigan in Flint research dispute

In October 2017 KWR conducted a scoping mission for the State of Michigan in the US to get a clear idea of the status of the multidisciplinary project,…

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MICRORISK: Microbiological risk assessment

The aim of MICRORISK was to develop a microbial risk assessment process which will contribute to the decision making process for risk management of drinking water. The drinking water production chain is…

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Antibiotic resistance in surface water and water treatment

Over the past few decades the use of antibiotics by humans and for veterinary purposes has grown sharply. Doctors in the Netherlands exercise restraint in prescribing antibiotics, but…

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Gertjan Medema International Member of U.S. National Academy of Engineering

11 February 2026 — Gertjan Medema is a pioneer in developing and applying detection methods for pathogenic bacteria, parasites, and viruses in…

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News

WHO extends KWR’s designation as Collaborating Centre

20 January 2026 — The World Health Organization (WHO) has renewed KWR’s designation as a Collaborating Centre on Water Quality and Health.…

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Blog

KWR at WaterMicro25: Science for Safe Water

09 July 2025 — From June 15–20, 2025, the international water microbiology community gathered in Amersfoort for the 22nd edition of the…

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News

Award-winning paper describes the ‘state of the science’ on wastewater surveillance of SARS-CoV-2.

01 April 2025 — The 2024 Willem Koerselman Prize was awarded on 1 April to Gertjan Medema for his contribution to the…

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News

PathoCERT strengthens resilience against waterborne pathogens

23 October 2024 — The European PathoCERT project has successfully strengthened the capabilities of first responders to react quickly and effectively to…

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News

Singapore honours Gertjan Medema with the Lee Kuan Yew Water Prize 2024

19 June 2024 — On 18 June, the President of Singapore, Mr Tharman, awarded KWR-microbiologist Gertjan Medema the Lee Kuan Yew Water…

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News

Marion Koopmans receives KWR Honorary Fellowship

09 November 2021 — Marion Koopmans, Professor of Virology, receives the KWR Honorary Fellowship 2020. She has been granted the honorific title…

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News

KWR involved in global COVID-19 wastewater monitoring effort

21 September 2021 — KWR Water Research Institute is helping develop the Wastewater SARS Public Health Environmental Response, or W-SPHERE, a global…

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News

Willem Koerselman Prize for 2020 goes to COVID-19 sewage-water research

14 June 2021 — The Willem Koerselman Prize was awarded on 10 June, underlining the social significance of KWR sewage-water research in…

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News

Researchers at KWR, Exeter (UK), Greece and Spain, awarded price for their video on ‘Sewers4COVID’

07 June 2021 — Sewers4COVID is a digital observation prototype that can quickly and cost-efficiently detect outbreak hotspots at a national scale. The…

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News

Sewage surveillance as an early warning system for SARS-CoV-2 detection

11 May 2021 — In recent research, we looked at how local sewage surveillance can provide information about the prevalence of the…

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News

Droplet Digital RT-PCR to detect SARS-CoV-2 variants of concern in wastewater

04 May 2021 — Wastewater monitoring has developed into a valuable and efficient tool to assess the prevalence of COVID-19 in the…

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News

Covid and the UK variant: the sewage tells the truth

13 April 2021 — Presence of Covid in the population Since the outbreak of the pandemic, already more than one year ago,…

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News

The Wastewater4COVID project aims to develop a method for early detection of the coronavirus

12 February 2021 — Early in the pandemic, Gertjan Medema demonstrated that genetic traces of SARS-CoV-2 in sewage correlate with COVID-19 disease…

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News

Scoping monitoring of coronavirus in wastewater in Peru

12 January 2021 — The current worldwide COVID-19 pandemic is a major concern for human health. The spread of this virus needs…

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Article

Wastewater surveillance into overdrive

31 December 2020 — The outbreak of the coronavirus in 2020 shifted KWR’s wastewater surveillance onto the fast track. Wastewater surveillance was…

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News

Concentration of SARS CoV-2 in sewage shows a descending trend

16 November 2020 — Since February 2020, we have measured the SARS -CoV-2 RNA in sewage water. By correcting the results for…

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News

Covid in wastewater: second wave as high as the first

06 November 2020 — As early as February, KWR demonstrated the connection between the number of SARS-CoV-2 viral particles in the sewage…

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