MADISON, Wis. — The University of Wisconsin Hospital performed a record 548 organ transplants last year, including 315 kidney transplants, even though the COVID-19 pandemic forced a temporary closure of part of its transplant program.

Mike Anderson, executive director of UW Organ and Tissue Donation, said an increase in deceased donors was a large factor. UW Hospital, one of the nation's largest transplant centers, had 173 deceased donors this year, up from the previous record of 150 set in 2016.

More people died from drug overdoses, and there was also an uptick in heart attacks, strokes and other events that can cause brain death — likely due to people with chronic diseases who put off medical care because of the pandemic, he said.

"It's not something we expected," Anderson told the Wisconsin State Journal. People who die from COVID-19 cannot be organ donors.

The number of transplants surpassed UW Hospital's previous record of 541 in 2005; the hospital's previous record for kidney transplants was 313, set in 2016.

The number of living donors went down in 2020. Part of that program was closed in the spring and again in November and December as coronavirus hospitalizations surged, said Dr. Dixon Kaufman, chairman of UW Health's transplant division. The hospital also saw a sharp drop in non-directed donors — people who give a kidney to a stranger without having a loved one or friend who needs one in return.

Kaufman said four transplant recipients contracted COVID-19, including two who apparently were infected at home after being discharged, and two who apparently got it during long hospital stays. All four are now fine, and the cases led to more frequent testing of patients and staff, he said.

The pandemic created other challenges: Doctors and others who fly in small airplanes to retrieve organs statewide had to be quickly outfitted with protective equipment, said Dr. Nikole Neidlinger, associate medical director of UW Organ and Tissue Donation.

Sensitive conservations to confirm consent for organ donation also had to be done with loved ones via Zoom or with medical staff wearing masks and face shields.

"Neither are ideal," she said. "But our team was able to overcome it, and the families in Wisconsin are really generous."