More than 800 people who traveled on the two ill-fated cruise ships that were quarantined tested positive for the coronavirus, the Centers for Disease Control and Prevention said in its weekly report.
Ten of the people who had been on the ships, the Diamond Princess and the Grand Princess, have died. The CDC said in the report that people should avoid traveling on cruise ships during the coronavirus pandemic.
"Outbreaks of COVID-19 on cruise ships pose a risk for rapid spread of disease beyond the voyage," according to the CDC's Morbidity and Mortality Weekly Report on Monday. "Aggressive efforts are required to contain spread."
Among the more than 3,700 passengers and crew aboard the Diamond Princess, 712 became infected with the coronavirus. The ship was put on temporary quarantine after a man who disembarked in Hong
Kong was diagnosed with the virus.
More than 60 passengers on one Grand Princess voyage stayed on the ship to embark on a second voyage. The CDC said many of the travelers from the first trip tested positive for the coronavirus and passed it to people on the second trip.
A total of 78 cases were confirmed on the Grand Princess, the CDC said.
The ship was on its way back to California when it was told March 4 to anchor off the coast after people on the vessel tested positive. Passengers were able to disembark after about a week in isolation.
One couple who were on the Grand Princess filed a $1 million lawsuit against the cruise line company, Princess Cruises, alleging that it exposed them to the disease.
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The report also said the coronavirus was found on various surfaces in cabins on the Diamond Princess 17 days after passengers had disembarked.
The CDC previously said the virus could be viable on surfaces for "hours to days." The agency said in its report Monday that the virus found in the cabins was "before disinfection procedures had been conducted" and that further study is needed.
Princess Cruises said in a statement that it volunteered to preserve the cabins so the CDC and health officials in Japan could collect data for further research on the coronavirus. Japanese health officials said the virus found on surfaces in the room were not live, the cruise line company said.
"Testing was intentionally conducted before disinfection occurred. These findings were expected because Princess Cruises voluntarily preserved these staterooms for this testing," the statement said.