On Thursday, a nurse wrapped in plastic protective gear peered through the shield covering her face and asked a patient how she was feeling.

The female patient was lying on a bed across from her son after both had been transported to the Johns Hopkins Hospital in Baltimore in a specially outfitted ambulance from Dulles International Airport in Virginia.

“I had some dizziness, nausea, and I believe I was exposed to something at the World Cup in Montreal,” said the patient, who had been diagnosed with a novel hemorrhagic fever. That’s in a family that includes Ebola, Marburg and yellow fever, nasty infections that can cause organ failure and death.

But her alarming case wasn’t real.

It was part of a drill involving multiple hospitals and agencies that federal health authorities oversee in the region annually to keep everyone’s skills sharp.

The mock public health crisis unfolded at the Hopkins Biocontainment Unit, one of 13 federally designated programs around the country where patients infected with the worst-of-the-worst contagions are isolated and treated by specially outfitted staff.

At a time when the United States has pulled back its engagement with the rest of the world and slashed public health programs, including vaccinations, the unit at Hopkins remains federally funded. The half-million-dollar annual budget pays for staff, equipment and training.

It’s a recognition that deadly pathogens remain a threat and don’t respect national borders, said Dr. Lisa Maragakis, an epidemiologist and executive director of the Hopkins unit.

“We’ve seen what happens when a pathogen gets out of control and spreads worldwide with COVID,” she said of the pandemic that killed more than a million Americans and wreaked havoc on daily life and the economy. “It threatens everyone. We need to do what we can to contain it.”

Ideally, pathogens are contained at the source. Ebola was largely kept in check in West Africa a decade ago. Without ready therapies, the highly contagious COVID-19 was not contained. Hopkins continues to use its biocontainment dollars to train other hospitals in how to isolate patients and get them extra care in the specialized units if needed.

Maragakis said she doesn’t fear just one pathogen from around the globe but many existing ones such as tuberculosis and new ones such an avian flu.

The public seems to have become exhausted by protective measures and is increasingly vaccine hesitant, she said. This is partially due to the rise of vaccine critics, including the Trump administration’s health secretary, Robert F. Kennedy Jr., who alarmed public health experts by recently dismissing a federal panel of vaccine advisers.

The biocontainment unit was created in 2015 specifically in response to Ebola, though it saw a lot more action when the coronavirus pandemic began in 2020.

Since then, it’s had suspected cases of hemorrhagic fever, said Chris Sulmonte, administrative director of the Hopkins unit. Typically, the cases are contagious pathogens with the potential to make people very sick and without specific known therapies to stop them.

The Hopkins unit on the East Baltimore hospital’s eighth floor is separated from other patients, and there are strict controls on getting in and out and putting on and taking off personal protective gear.

The patient, Carrie Billman, works at Hopkins and volunteered to play sick. Her day job involves training the unit’s staff members, including in how to properly dress and remove the gear so they don’t expose themselves or others with a pathogen.

She watched as staff wheeled her real 13-year-old son, Ryan, into the unit, his body enveloped in what looked like a foil food wrapper and a surgical mask. The pair had been picked up in a specially designed Hopkins ambulance from Dulles.

Swathed in their own protective gear, nurses put him in a bed and hooked him up to machines to monitor his blood pressure and oxygen levels.

“They all did their jobs,” said Carrie Billman, observing a staff of seven in the room.

There are about 100 Hopkins clinicians from 20 specialties who volunteer to operate the unit, which has four beds. They train quarterly at the hospital, in addition to major regional drills.

This kind of capability doesn’t just exist on the ground. This year, federal leaders at the Department of Health and Human Services tested a new portable biocontainment unit used in airplanes to transport patients for care.

There’s another potentially helpful byproduct of drills, Sulmonte said, at Hopkins.

“We want everyone to know what we do,” he said. “We have to be ready at eight hours’ notice.”