The University of Pittsburgh Medical Center voluntarily suspended transplants at UMC Presbyterian after three transplants. The transplants were stopped after it was found that patients who underwent the procedure died after contracting a fungal infection.

UPMC Chief Medical and Scientific Officer Dr. Steven D. Shapiro said in a statement that the transplant program has been suspended till the time the investigation into the case will be completed.

Shapiro said on Monday that the suspension of the program could last two or three days. He said the medical center is trying to contact all the patients with scheduled organ transplants and will do everything to ensure patients receive life-saving transplants if they are critically ill.

Officials said they are trying hard to know the source of the mold that infected patients at UPMC. The fungus isn't some kind of killer mold. It's a household kind ordinary indoor mold.

UPMC said it believes the mold may have contributed to the deaths of organ transplant patients. One transplant patient died Thursday at UPMC Montefiore, the medical center said.

Two other patients died in October and in June at UPMC Presbyterian, CNN affiliate WTAE-TV reported. And UPMC said another patient became deathly ill with the same kind of mold infection.

The medical center said, "The mold that causes infections like this is common in the environment and is not a risk to anyone except those who are most severely immunocompromised".

Patients who recently received transplants at UPMC Presbyterian have received an antifungal medication, even though they are not infected.