A superspreader Santa Claus has reportedly given a gift that no one wants—COVID-19—to at least 75 residents and staff of a nursing home in Mol in Antwerp, Belgium after a goodwill visit last week.

Authorities say the son of one of the residents dressed up as Sinterklaas, or Santa Claus, to spread holiday cheer to the 169 locked down residents of the Hemelrjck Home. But a few days later, first 57 and now 75 staff and elderly residents have tested positive for the potentially deadly virus, according to The Brussels Times.

“It was made with the best intent, but it went wrong,” Wim Caeyers, the town mayor said of the unfortunate event. “It is a very black day for the care home.”

Now health workers are trying to mitigate the spread so it doesn’t pass to the other residents. “It is a very great mental strain to bear for the man that played Saint Nicholas, as well as for the organizers and the staff,” Caeyers told a local TV channel. “It will be all hands on deck during the coming week.”

The allegedly infected Santa did wear a mask during the initial visit, but photos posted on social media by family members show that he took it off for the camera. “Initially they said that the rules had been followed,” Caeyers said. “But then straight away you receive photos from the families of residents where you can see that this wasn’t the case.”