UPMC's mold problem a difficult one to fully solve
As federal investigators probe a rare mold outbreak at UPMC, experts say the focus will be on how well the hospital handled a nearly impossible task: preventing a common organism from getting into the building.
“It isn't really possible to reduce the risk for fungal infection to zero,” said Dr. Daniel J. Diekema, director of the division of infectious diseases at the University of Iowa Carver College of Medicine.
Representatives from the federal Centers for Disease Control and Prevention arrived in Pittsburgh on Tuesday to investigate how a type of mold commonly found in soil, leaves and wood reached transplant patients whose weakened immune systems made them vulnerable. UPMC voluntarily shut down its internationally recognized program Monday.
Four patients contracted mold infections during the past year in UPMC Presbyterian and UPMC Montefiore, UPMC officials said. Three of those patients died, though their deaths cannot be directly attributed to the infections. A fourth transplant patient has a mold infection and remains hospitalized. UPMC has said it found three different species of mold in the patients.
“When we look at outbreaks in hospitals and we are looking for a point source, a smoking gun, we usually see organisms of the exact same species. That apparently is not the case there,” Diekema said.
UPMC identified the types of mold detected as rhizomucor, lichtheimia and rhizopus, part of a family of molds known as mucormycetes.
“They are rare infections,” said Dr. Mary Brandt, chief of the CDC's mycotic diseases branch. “They don't happen very commonly, but these different kinds of molds are a threat to these patients.”
The CDC's team includes a senior epidemiologist, two medical professionals training to be epidemiologists, and a medical student, Brandt said. Pennsylvania Department of Health officials are investigating. The federal team will look for the cause of the outbreak and will evaluate what the hospital has done to mitigate risks to patients and to protect against outbreaks, she said. The investigation will culminate in a federal report.
Sept. 3, UPMC said it found mold inside the wall of a patient room in Presby's cardiothoracic intensive care unit — the same place where three of the four affected patients had been treated. Five days later, investigators discovered mold in modular toilets in other ICU rooms, which prompted closure of the unit and relocation of all its patients.
Ventilation systems, leaky pipes and laundry are likely suspects, said Dr. Ernest Chiodo, a Chicago-based industrial hygienist who investigates mold contamination.
Hospital linens carried a similar mold into a New Orleans children's hospital, and five children infected with the mold died, according to a CDC report published in the Pediatric Infectious Disease Journal in 2014.
Thirteen people were infected after a 2011 tornado in Joplin, Mo., carried pieces of contaminated debris into their bodies. The infections killed five.
“In any group of people, when anyone has a mucormycetes infection, about half of those patients will die,” Brandt said. She said the CDC investigates about one to three mold outbreaks a year.
Mortality can be even higher among people with compromised immune systems, including organ transplant recipients.
Recipients take medications known as immunosuppressants to prevent a recipient's immune system from attacking the donor organ's cells and rejecting the organ, Diekema said.
While immunosuppressants are necessary, they hinder the immune system's ability to battle infection.
“It's a very delicate balance, trying to make sure that the immune system does not reject the donor organ and trying to preserve a patient's immune system to fight infection and make sure it does not attack the new organ,” Diekema said.
Antifungals are sometimes used to fight infection, but the medications are not always effective and have serious side effects, experts said. UPMC said it has prescribed a brand of antifungals called Cresemba as a precaution to 11 recent Presby transplant patients.
UPMC has deployed disinfecting robots that use ultraviolet light to sanitize hospital operating and patient rooms and replaced microfilters in all air handling units. The hospital system is rechecking air seals around windows and doors and sealing laundered linens in plastic for patients with compromised immune systems.
While mold infections are rare, they are a known risk that must be considered, said Dr. Daniel Kaul, chairman of the United Network for Organ Sharing's Disease Transmission Advisory Committee.
“Every hospital that deals with immunosuppressed patients will see these kind of infections from time to time … sometimes the biggest health risk to people is not getting an organ transplant.”
Wes Venteicher and Ben Schmitt are staff writers for Trib Total Media.