Last week, researchers from the University of Surrey uploaded their complete data set to the Open Science Framework and warned of “serious concern regarding compliance with hygiene regulations in high-risk environments,” according to the release. During a 19-week period, the team covertly monitored two public washrooms at Bispebjerg Hospital in Copenhagen and recorded more than 2,600 toilet flushes; 43.7 percent of users failed to run the tap within the four-minute window that followed, and one week the share rose to 61.8 percent, the group told BBC News.
Temperature sensors affixed to toilet and sink pipes registered every flush and faucet activation. Any visit without faucet use two minutes before or four minutes after a flush counted as a missed handwash.
“Many people may assume that handwashing is now taken for granted—especially in hospitals and after Covid-19,” said Pablo Pereira-Doel, the University of Surrey behavioural scientist who led the project, according to Die Presse. “But our data paint a different picture.” Carrie Newlands, a co-author, called the findings “worrying but not surprising” and noted that simple behaviours “can lapse without reinforcement,” Die Zeit reported. “Strategies that raise awareness at the crucial point in a bathroom visit—like singing Happy Birthday twice—can help people build habits that last,” added fellow researcher Benjamin Gardner in a statement to BBC News.
The log revealed that non-handwashing peaked at the start and end of each day and around mealtimes, moments when pathogen transfer risk may be greatest. Infection-control teams have long warned that low compliance lets doctors, patients, and visitors spread microbes, including drug-resistant strains.
Health agencies elsewhere still emphasise the basics. Guidance from NHS England lists handwashing as a primary defence against food poisoning, influenza, and hospital-acquired infections. Germany’s Federal Institute for Public Health urges citizens to scrub for 20–30 seconds—“about as long as it takes to hum Happy Birthday twice”—and suggests using elbows or disposable towels to operate taps.
Managers at Bispebjerg Hospital said they would act on the study. Innovation manager Brian Holch Kristensen told Jyllands-Posten that staff might relocate hand-gel units so they complement rather than replace soap and water, or install soap dispensers that light up or beep if hands are not washed soon after flushing. A 2015 trial at Hvidovre Hospital and Rigshospitalet found that beeping dispensers more than doubled compliance from 30 to 70 percent.
Hospital officials admitted that many patients and visitors underestimate how quickly hands pick up germs on a ward. The Infection Hygiene Unit already distributes the brochure Stop the Infection, posts reminders near shared refrigerators and water coolers, and offers assistance to bedridden patients.
Because earlier self-reported surveys tended to inflate compliance, the Surrey team argued that objective monitoring and behaviour-focused nudges—eye-level posters, illuminated soap dispensers, or jingles—could convert pandemic-era messaging into lasting habits. Statens Serum Institut estimated that up to 10 percent of Danish patients acquire infections during hospital stays, underscoring the need for renewed campaigns.
The preparation of this article relied on a news-analysis system.