Health minister Ernst Kuipers has warned about the “sky high” number of coronavirus infections in the Netherlands and urged people not to attend Christmas events if they have symptoms.

“We have never had such as high proportion of coronavirus particles in waste water,” he said. “You can assume that many hundreds of thousands of people are infected with coronavirus. There is a real likelihood that someone close to you has it.”

Figures from the government’s coronavirus dashboard show the number of Covid patients on nursing wards in hospitals rose again in the week to Wednesday, but less than the week before. The number of Covid patients in intensive care units has also continued to rise, but is still relatively low nationally, health officials say.

Friday is the last day that top up coronavirus vaccinations are available and just under half the target group (some 2.5 million) have actually had a booster, Kuipers said. And that presents a risk during the Christmas festivities.

“Everyone wants to spend time with family and friends, and that is what we should be doing,” Kuipers said. “But if you have symptoms, be careful and don’t join in for Christmas dinner. There is a real chance that you have coronavirus and could infect other people.”

Kuipers said he was not surprised by the high figures because the ministry assumed the virus had a seasonal link. “We had very low numbers in the summer,” he said. “Now you see the figures going up again in the autumn.”