CDC: Air pressure played role in patient mold infections and death

Last September, four postoperative transplant patients at the University of Pittsburgh Medical Center (UPMC) died after contracting mucormycete mold infections. Three of the four patients had been housed in a negative pressure room at UPMC Presbyterian facility because the cardiothoracic ICU was full. While the Centers for Disease Control and Prevention (CDC) is still investigating the deaths, its “Notes from the Field” report says the room’s air pressure may have had a role in their deaths.

 “Caring for immunosuppressed patients in negative-pressure environments has been previously identified as a risk factor for invasive mold infections, possibly related to the potential to concentrate dust and mold spores in these rooms,” the CDC wrote. “Negative-pressure rooms are recommended for isolation of patients with a suspected or confirmed airborne infectious disease; this investigation highlights how unnecessary placement of immunocompromised patients in negative-pressure rooms could result in net harm and therefore should be avoided.”

When a door between a negative-pressure and positive-pressure room is opened, air rushes into the negative-pressure room. The negative pressure in the patients’ room meant that every time the door was opened, air potentially containing bacteria and viruses blew in.

Researchers noted that none of the three transplant patients had an infectious disease prior to being placed together and only contracted mold infections after being placed in the negative-pressure room. The fourth transplant patient contracted a mold infection at UPMC’s adjoining Montefiore hospital. The CDC recommended in December that UPMC stop placing immunocompromised patients into negative-pressure rooms, a directive the facility immediately complied with. The agency recommends that other facilities follow the same protocol.

Maintaining the correct air pressure is an area that many facilities struggle with, with a 2015 John Hopkins study finding that excessive foot traffic compromises the air seals in operating rooms.