Hundreds of people who celebrated the Christmas holiday with peace of mind after testing negative for COVID-19 were notified a day later that they were actually sick with the virus. The BBC reports that a total of 886 people were affected by the screw-up at a lab in Sydney, Australia, and 486 of them were later confirmed to be infected with the virus. The lab, SydPath, copped to the mistake in a statement Tuesday, saying it had occurred amid an “unprecedented” amount of tests. “Unfortunately... a simple data processing error was made which led to the wrong test results being released,” the lab said. The fiasco comes as New South Wales struggles with a surge of infections driven by the highly contagious Omicron variant. Those who received false test results have now been left with the horror of wondering if their loved ones are going to fall ill. “If (my niece and nephew) are positive, I’m the one to blame because I’ve infected them now,” Stephanie Colonna told The Today Show.