One patient dead. Five others infected. A thousand surgeries postponed and 3,000 people told to watch for infection symptoms.

That’s the toll so far from mold problems at Seattle Children’s Hospital that forced the shutdown in May of all main operating rooms on its main campus in Seattle. The hospital says issues with its air-filtering system were probably at fault.

The six patients who developed infections — three last year, three this year — were more at risk from the mold because of their medical procedures, according to the hospital, which U.S. News & World Report consistently ranks as one of the best children’s hospitals in the country and this year rated top in the Northwest. The death stemmed from an infection in 2018 but occurred this year.

Mark Del Beccaro, chief medical officer at the children’s hospital, announced at a news conference Wednesday that the operating rooms would reopen Thursday, as daily air-testing results indicated the facilities were safe.

“For most patients, the risk is very low that they could get an infection,” he told The Washington Post earlier. “The infections we had were in very specific types of procedures, but out of the caution that we have to make sure everybody is safe, we’ve closed everything.”

Most people can breathe in the fungus behind the infections, called Aspergillus, without health issues, according to the Centers for Disease Control and Prevention. But the mold is more likely to cause problems — such as allergic reactions or lung and organ infections — for people with already compromised immune systems, the CDC says. That’s why medical centers such as Seattle Children’s Hospital work to filter spores out of their air.

A May investigation by the hospital found problems in its air system, including gaps in filters that could let spores through. Since then, the hospital has upgraded its air handler, installed a new humidification system and sealed potential air leaks in its operating rooms, according to spokeswoman Alyse Bernal. It has also deep-cleaned its rooms and started disinfecting surfaces with ultraviolet light, she said.

“We are very sorry for the impact the air quality issue in our operating rooms has had on our patients and families, and we are taking this situation very seriously,” Bernal told The Post in an email.

She declined to share details about the infected patients, citing their privacy. However, Del Beccaro said at the news conference that the hospital does not believe the five infected have a "life-threatening condition.”

Other medical centers are working with the children’s hospital to take over the most-urgent disrupted surgeries, Del Beccaro said, but that still left more than 1,000 patients with their operations postponed.

Serving what the hospital says is the largest region of any children’s hospital in the United States, Seattle Children’s has locations in four states but has its main campus in the Laurelhurst area of Seattle.

With procedures at Seattle Children’s Hospital in limbo, Harborview Medical Center has absorbed more than 70 of its surgeries and has 19 more scheduled in the coming days, said Tina Mankowski, a spokeswoman for University of Washington Medicine. UW Medical Center has performed 12 operations and is taking others on a case-by-case basis, she added.

"Both hospitals are working with Seattle Children’s to make sure that they do what they can do to help them,” Mankowski said.

The children’s hospital first became aware of the mold problem when patients who had surgeries in March and April of last year developed infections, Del Beccaro said. Mold spores floating in the air can get into bodies opened up for surgery, then slowly turn into an infection once the wound is closed, he added.

The hospital traced the issue to a few rooms, cleaning them, sealing potential air leaks and in some cases remodeling to minimize the chances for spores to enter, he said.

The hospital did not find evidence of a broader issue, got good air-testing results and saw no infections for nine months, according to Del Beccaro.

“We believed that the work we had done to those rooms had solved the problem,” he said.

The hospital reached out at the time to the public health department for Seattle and King County, which put it in touch with the CDC for help dealing with the mold, according to James Apa, a spokesman for the department.

The CDC provided its expertise and “ultimately determined that Children’s was taking the right approach to address the situation at that time,” Apa wrote to The Post. Neither the county health department nor the CDC produced reports, he said.

County officials also passed the issue on to the Washington State Department of Health. The department opened an investigation but “found no deficient practices,” a state spokesman said.

But the hospital was struck by mold again this spring. On May 18, the hospital closed four operating rooms where mold had been detected, continuing to perform some procedures in other areas, according to the hospital.

By May 24, though, the hospital had closed its other 10 operating rooms, which Del Beccaro said was necessary to fix the facility’s air system and also spurred by additional mold findings.

State and federal government groups scrutinizing the children’s hospital in the wake of the new infections have presented the hospital with their concerns.

Kristen Maki from the Washington State Department of Health told The Post that Aspergillus infections do not necessarily violate hospital licensing laws but can indicate “that the facility’s systems may not be compliant.” Since hearing from Seattle Children’s in May, the department has visited the hospital and opened an investigation into the facility’s state license.

The Centers for Medicare and Medicaid Services is conducting its own investigation and found “deficiencies,” the federal agency told The Post. CMS said it is working with the state health department to monitor the effect of the closed operating rooms on health-care access and on June 20 sent the children’s hospital a summary of problems.

CMS said it is still reviewing the plan the hospital submitted to correct the issues. The hospital could lose its participation in Medicare and Medicaid programs if it cannot show it is in line with standards.

Del Beccaro said the hospital is not worried about repercussions from CMS, though.

“We believe that the work plan we’ve submitted and the work we’ll do ... will allow them to say we’re in compliance,” he said.