Willemijn Lodder works as senior scientific researcher for the National Sewage Surveillance at RIVM. She connects data with virological characteristics. Willemijn studied at HU University of Applied Sciences Utrecht and specialised in molecular biology. She did PhD research on viruses (including polio and hepatitis A) in the environment (surface water and sewage). Together with colleagues, she set up the new department within RIVM dedicated to sewage research. This research is used for COVID-19, polio, influenza and monkeypox, among others.