Residue of the coronavirus was found on surfaces inside of cruise-ship rooms up to 17 days after infected passengers left the ship.
The finding, which is considerably longer than previously thought, was unveiled in a report by the Centers for Disease Control and Prevention. Researchers examined the rooms of infected passengers on board the Diamond Princess and still found traces of the coronavirus nearly three weeks after those passengers— both those who had symptoms of the virus and those who didn’t— had disembarked. Diamond Princess is operated by Carnival Corps’ Princess Cruises and reported more than 700 coronavirus cases.
The CDC said the 700 passengers spread the virus before the ship went into quarantine, causing infections among the crew to rise afterward.
An earlier analysis found that the virus lived for up to three days on plastic and stainless steel surfaces, according to Bloomberg. The coronavirus didn’t last as long on copper or cardboard, where no traces of the virus were found after four hours and 24 hours, respectively, according to the report in the New England Journal of Medicine.
This is believed to be the first time the CDC has found that the virus remained on surfaces for such an extended time period than what was previously found. However, CDC’s Morbidity and Mortality Weekly Report said it was unknown whether the coronavirus found on the surfaces inside the cruise cabins caused any of the 700 coronavirus cases.
Coronavirus has shut the U.S. cruise industry down after widespread outbreaks, and legislators are currently studying the safety of cruise ships going forward.
The Diamond Princess was quarantined off of Yokohama, Japan, and its sheer number of coronavirus passengers represented the largest outbreak outside of mainland China at one point.
The latest study looked at uncleaned rooms and their surfaces. Other research found that properly cleaning the rooms of COVID-19 patients showed effective results at killing the virus.