Corrections & clarifications: The Centers for Disease Control found that novel coronavirus RNA, or genetic material, not the coronavirus itself, was identified on surfaces in Diamond Princess cruise ship cabins up to 17 days after cabins were vacated.

A new Centers for Disease Control and Prevention report into the spread of the novel coronavirus on cruise ships looked into the rapid spread of the disease on the ships and beyond individual voyages.

The CDC noted there was coronavirus RNA, or genetic material, found on surfaces in the cabins of both symptomatic and asymptomatic infected passengers on the Diamond Princess cruise ship – 17 days after passengers had left the cabins. Of note, the cabins had yet to be disinfected.

While the data doesn’t show if transmission of the virus occurred from surfaces, the CDC report recommends exploring that further.

“Just as mosquitoes spread malaria and ticks spread lime disease, cruise ships have been spreading coronavirus,” former CDC director Dr. Tom Frieden told the USA TODAY editorial board and reporters on Tuesday when asked about the report.

The report outlines the responses on board several high-profile cruise ships, including the Diamond Princess and Grand Princess. Between the ships, there were more than 800 COVID-19 cases that led to 10 deaths.

“Not mentioned in the report is the fact that Princess Cruises volunteered to preserve select staterooms onboard Diamond Princess, known to have been occupied by positive cases,” Princess Cruises said in a statement to the trade publication Cruise Industry News. “This testing was done in full collaboration with the Japan Ministry of Health and U.S. CDC.

It continued, “According to researchers with Japan’s National Institute of Infectious Diseases, what was detected on surfaces was SARS-CoV-2 RNA*, NOT live virus, in select cruise ship cabins after they were vacated, and this testing was intentionally conducted before disinfection occurred. These findings were expected because Princess Cruises voluntarily preserved these staterooms for this testing.”