PITTSBURGH — A fourth lawsuit has been filed blaming the death of an organ transplant patient on a mold outbreak at University of Pittsburgh Medical Center hospitals.

The latest was filed by the family of Daniel Krieg, 56, of St. Marys, Elk County, the Pittsburgh Tribune-Review first reported Wednesday. Krieg died July 9 at UPMC Montefiore hospital.

Krieg had a kidney transplant in July 2015, then returned to the hospital eight months later with viral pneumonia. An autopsy determined he died of multi-organ failure due to sepsis, but also had mold in his lungs. Mold can cause pneumonia which, in turn, can cause sepsis, which occurs when the body’s immune system releases chemicals into the bloodstream that can attack or compromise major organs.

The newest lawsuit, like the others, blames the mold on specially ventilated hospital rooms that are meant to decrease the spread of infectious diseases.

Two similar previous lawsuits filed by the families of other transplant patients who died have each settled for $1.35 million. A third suit still pending in the courts was filed by the family of Che DuVall, a 70-year-old lung transplant patient who died at another hospital, UPMC Presbyterian, in February.

The U.S. Centers for Disease Control and Prevention has said organ transplant patients who developed mold infections at UPMC hospitals likely got them from time spent in “negative pressure” rooms normally reserved for those who already had infections. The hospital network suspended its transplant program in September 2015 but resumed it about a week later after a review of procedures and treatments.

Negative pressure rooms are used to ensure air from them does not leak into other areas of the hospital to prevent other patients from being infected. But the ventilation system used, which draws outside air into the rooms, could also increase the likelihood of infections for those housed in the rooms — especially if they’re taking drugs to suppress their immune systems. Transplant patients commonly take such drugs to lessen the chance of organ rejection.

UPMC has previously said the bed used to house Krieg was in an area where negative pressure ventilation could have been used, but has said it wasn’t in Krieg’s case. Krieg’s attorneys contend the ventilation was used during part of his hospital stay, however, and further that Krieg wasn’t given anti-fungal medications like other transplant patients after the mold outbreak until it was too late.

“Our sympathies are with Mr. Krieg’s family, and the doctors and nurses who cared for him,” UPMC said in a statement Wednesday. “We continue to work with our local, state and federal partners to better understand and learn from the course of his illness.”