Overnight the number of passengers and crew onboard the cruise ship Diamond Princess who have tested positive for the coronavirus has nearly doubled, from 70 to 136. An additional 66 people on board the quarantined cruise ship have tested positive for the virus. Among those testing positive are 23 Americans. The ship is being held in quarantine in the port of Yokohama, Japan.

Only 336 of the roughly 3,600 people onboard had been tested as of Monday, according to the Japanese health ministry. Japan Times reports that the Japanese government is now preparing to test dozens of elderly passengers as it investigates potential issues with hygiene control on the infected ship.

But Chief Cabinet Secretary Yoshihide Suga indicated during a news conference Monday afternoon that it would be difficult to test all of the passengers and crew, adding that testing will be prioritized for people with potential symptoms and the elderly.

ABC reports that the overall pattern for coronavirus remains stable. Eighty percent of cases are mild and about 15% require hospitalization. Roughly 3%-5% of people will need intensive care and 2% of cases are fatal.

China reports 908 deaths and about 40,000 cases of coronavirus. On Sunday alone, 97 people died, the highest daily death toll since the outbreak began. Almost 6,500 of the affected patients were in critical condition, authorities said Monday.