Ms. Benner had been prepared for the possibility since early in February, when 15 Americans who had been exposed to the coronavirus on a cruise ship that docked in Japan were transferred to Nebraska Medicine, the hospital where she works in Omaha, Neb. The hospital campus includes a 10-bed biocontainment unit for serious treatment, as well as a 20-bed quarantine unit, the only federal quarantine unit in the country.

As a nurse and clinical program coordinator, Ms. Benner regularly practices how to treat infectious diseases. Still, she could not help but wonder, “Am I ready for this?”

Her mind flashed to her 1-year-old and 2-year-old children, wondering if there was a chance that she could put them at risk. Then she thought of her many years of training.

She arrived at work at 6:30 a.m. the next day, and slid on her purple scrubs.

“I walked in there, I took a deep breath, and I said, ‘We’re doing this today,’” said Ms. Benner, who treated two patients with the coronavirus on Feb. 26. “This is my time to make sure I apply everything that I’ve been teaching to protect myself, my family and everybody within the community.”

Two patients who had tested positive were being treated that day in the biocontainment unit with mild symptoms, including a cough, she said. Wearing coveralls, boots and a full respirator mask, she dosed out medicine, served lunch and helped pass the time through conversation.

“We just talked about family, where we’re all from, if they would ever go on another cruise again,” she recalled.