Hundreds of Americans who had been passengers on a coronavirus-stricken cruise ship in Japan landed in the U.S. on Monday, with 151 arriving at Joint Base San Antonio-Lackland.

Of the passengers on board the flight into San Antonio, seven tested positive for coronavirus, and went on to Omaha, Nebraska, where they will be treated at the University of Nebraska Medical Center, senior State Department officials said Monday.

Prior to flying out on chartered cargo jets late Sunday, 14 Americans tested positive for the virus, but were allowed to join the evacuation operation, a decision made by the U.S. Embassy, said Dr. William Walters, managing director at the U.S. Department of State.

“These are people who were already in the evacuation pipeline, and already on their way to an aircraft because they were asymptomatic,” Walters said, noting that all 338 people were examined by American medical professionals and had no symptoms when they exited the ship. Just prior to boarding the aircraft, the government of Japan notified U.S. officials that some people tested positive for coronavirus, Walters said, noting that there is a delay of two to three days to receive test results.

American evacuees from the Diamond Princess cruise ship arrive at Joint Base San Antonio-Lackland on Feb. 17, 2020 in San Antonio, Texas. Credit: Edward A. Ornelas/Getty Images

“If those results had come in four hours earlier before they were evacuated from the ship, it would have been a different discussion. By the time we got this info, these people were already on [one of 15 buses en route to an aircraft.] Once they were in the isolation area, it was safest for us to keep them in there.”

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Walters said that the decision to evacuate people testing positive for coronavirus was two-fold: First, the “primary responsibility of the State Department is of the well-being of Americans overseas,” and second, the cargo planes carrying these passengers are large, giving room to create an isolation area kept separate from crew and other passengers.

Officials said the cargo aircraft was broken into sections, with one 18-person section at the end outfitted with sheets of 10-foot tall plastic on four sides of the isolation area to protect others on the plane from any germs that might spread as the “airflow in the aircraft is nose to tail.”

During the flight bound for San Antonio, two additional people were placed in isolation after developing a fever, and were moved from the general area to the quarantined section of the aircraft.

“We had additional expertise and eyes on these people, and monitored them throughout the flight,” said Walters, executive director for the Bureau of Medical Services at the U.S. Department of State.

Walters said the evacuation is something the State Department has been preparing for during the last 18 months with Japan’s Ministry of Health.

“We have been doing run-throughs on how to repatriate Americans from Japan” should there be a highly contagious pathogen, he said. “Much of that work paid off in spades in our ability to safely recover Americans off that ship.”

Over 3,600 people, including more than 400 Americans, were on board the Diamond Princess cruise ship, which has been quarantined for more than a week at the port of Yokohama after the coronavirus was diagnosed in a man who had disembarked days earlier in Hong Kong.

Currently, roughly 60 Americans are still in Japan and being tracked by the State Department. Those being housed at Joint Base San Antonio-Lackland will spend the next 15 days quarantined to monitor their health, officials said.

“As of today, the risk to the general public of contracting COVID-19 continues to remain low,” stated Mayor Ron Nirenberg. “Every precaution has been taken to keep the public isolated from these travelers who are in a precautionary quarantine and any travelers who have shown symptoms of the virus. Our residents should continue to go about their lives.”

Roseanna Garza

Roseanna Garza reports on health and bioscience for the San Antonio Report.