Adding to the challenge of caring for the largest patient population in the country with fungal meningitis, staff at St. Joseph Mercy Ann Arbor also are seeing a number of previously discharged patients returning to the hospital for inpatient treatment.

About 30 percent of fungal meningitis patients that have been discharged from the Ann Arbor hospital return with an epidural abscesses, according to Joyce Young, chief nursing officer.

“What we are finding is truly remarkable,” Young said.

The hospital has had to grapple with an ever-fluctuating population of fungal meningitis patients, and its inpatient beds are nearly at capacity. Because of the specialized, around-the-clock care and monitoring needed for the fungal meningitis patients, St. Joseph Mercy Ann Arbor has opened a previously vacant wing of rooms.

The state of Michigan granted emergency approval for the new beds, and fast-tracked the licenses for a number of nurses from other Trinity Health System hospitals brought in to relieve the hard-working staff in Ann Arbor.

Tuesday, Trinity Health President and CEO Joe Swedish visited the Ann Arbor hospital to thank and commend staff members for their response to the outbreak.

“Saint Joseph Mercy Health System is at the epicenter of the outbreak, treating more than a quarter of the nation’s patients,” according to a written statement from Swedish. “The medical staff, nurses, and all associates have set the standard in how to effectively manage this unprecedented outbreak. They are the unsung heroes who have risen to a challenge that is rarely felt by hospital systems. Their swift and proactive response demonstrates steadfast commitment to our mission and values of delivering high quality, compassionate and patient-centered care.”

St. Joseph Mercy Ann Arbor quickly emerged as one of the nation’s hospitals dealing with an influx of patients in an outbreak of fungal meningitis that the Centers for Disease Control and Prevention began investigating in the beginning of October.

The CDC pinpointed the New England Compounding Center in Framingham, Mass. in its investigation, a compounding drug manufacturer that reportedly distributed batches of injectable steroids that had been contaminated with fungus to numerous clinics across the country.

Four clinics in Michigan received contaminated batches of the steroids, which were used as injections for pain relief. One of those clinics was Michigan Pain Specialists in Brighton. Many physicians that practice at St. Joseph Mercy Ann Arbor also privately practice at the Brighton facility, hospital staff has said. The Ann Arbor location is serving as the treatment hub for all of the Trinity Health System hospitals in Southeast Michigan.

St. Joseph Mercy Ann Arbor was caring for 49 patients in connection with the fungal meningitis outbreak as of Friday, down from 74 patients that had been hospitalized Tuesday. The patients that could be discharged from the hospital for Thanksgiving were allowed to go home, said Laura Blodgett, spokeswoman for St. Joe’s.

All of the patients currently being treated at St. Joseph Mercy Ann Arbor received the initial steroid injection for pain in a Michigan facility.

The hospital has cared for 133 of the 167 patients in Michigan connected with the fungal meningitis outbreak. Of those 133 patients, 75 of them developed what hospital staff call “epidural abscesses.”

An abscess is a collection of infection. For fungal meningitis patients, the abscesses are located at the site of their injections.

Patients are often screened for epidural abscesses in an MRI, where hospital staff looks for fluid collection or other changes in the patient’s bone that would suggest an infection.

Meningitis, the inflammation of the brain or spinal cord, is rarely caused by a fungal infection and so the course of treatment is not well established. More commonly, meningitis is caused by a virus or by bacteria. Symptoms include fever, neck pain and headaches.

Patients with fungal meningitis are treated with extremely toxic drugs intended to treat fungal infections, and each person reacts to the medication differently.

The drugs are extremely hard on the patients’ blood vessels and veins when administered intravenously, and cause numerous side effects including hallucinations. When a patient no longer has negative side effects from the medication and is well enough to go home, they are discharged and given the medication in an oral format.

Thursday, Michigan health officials reported that the number of resident deaths attributed to fungal meningitis had risen to 13, a figure that includes three Michigan residents that received injections for pain at facilities in Indiana.

Across the country, 490 people have been infected in connection with the fungal meningitis outbreak, including 34 deaths. Amy Biolchini covers Washtenaw County, health and environmental issues for AnnArbor.com. Reach her at (734) 623-2552, amybiolchini@annarbor.com or on Twitter.