On Wednesday, the South Korean Centers for Disease Control and Prevention announced 15 additional cases, bringing the total number to 46 -- an increase of almost 50% in one day. Singapore has at least 81 cases and Japan has 68 cases and one death, not including the more than 500 cases aboard the virus-stricken cruise ship docked in the Japanese city of Yokohama.

Amid the sudden spike in numbers, Japan's health ministry has issued guidelines for people experiencing symptoms similar to the coronavirus in an effort to to prevent worried citizens from inundating hospitals by providing them with specific hotlines to call.

China praises virus response

In China, promising signs have emerged of a potential leveling off in the rate of infection. Outside of Hubei, the province at the epicenter of the outbreak, the number of new cases dropped for the 15th consecutive day, according to the country's National Health Commission.

Chinese President Xi Jinping said in a phone call with British Prime Minister Bros Johnson on Tuesday that China's measures to prevent and control the epidemic "are achieving visible progress," according to state news Xinhua.

Xi said, "the battle has reached a crucial time" and China had "mobilized the entire country, and adopted the most comprehensive, rigorous and thorough prevention and control measures," Xinhua reported.

"Thanks to those arduous efforts, the situation is witnessing positive changes," Xi said.

Headlines across Chinese state media on Wednesday morning were full of positivity, touting China's ability to get on top of the virus's spread. One commentary in Xinhua said the fight against coronavirus would "not stop China's march towards rejuvenation."

Meanwhile, Hu Xijin, editor in chief of the state media outlet Global Times, tweeted that the country was on its way to victory.

"Daily new infection cases outside Hubei fell below 100 for the first time according to data released on Tuesday. We are on the way to the victory," tweeted Hu.

But experts have warned that it is too soon to tell whether the virus is under control.

"This trend must be interpreted very cautiously. Trends can change as new populations are affected. It's too early to tell if this reported decline will continue. Every scenario is still on the table," Tedros Adhanom Ghebreyesus, director-general of the World Health Organization (WHO), said during a press conference Monday.

Stringent and often draconian measures are also being ramped up in much of the country. CNN analysis found that on Chinese government orders, some 780 million people are still living under some form of restrictive movement, including all of Hubei, the northeastern province of Liaoning, and China's two most important cities, Beijing and Shanghai.

It comes as authorities make an effort to return to something like normality in many major cities and commercial hubs, with the long break forced by the outbreak taking its toll on the country's economy.

On Tuesday, Liu Zhiming, director of the Wuchang hospital in Wuhan, the city at the center of the outbreak, himself died of the virus, according to a statement released by local government authorities.

Liu was a neurosurgeon and the most senior health worker known to have died as a result of the coronavirus epidemic. His death could renew criticism that the government has not done enough to protect frontline medical workers, many of whom are overworked and overstretched.

Passengers start leaving Diamond Princess

Outside of mainland China, the worst single outbreak has been on board the Diamond Princess cruise ship, under tight quarantine for two weeks in the Japanese port of Yokohama, south of Tokyo. More than 545 of the 3,600 people on board have tested positive for the virus so far. On Tuesday, 88 new cases were reported.

On Wednesday morning local time, passengers began to disembark from the ship after Japan's health ministry ended the quarantine period.

Questions have been raised, however, over the effectiveness of the isolation procedures onboard and whether disembarking passengers could pose a risk to the public as more test positive for coronavirus after leaving the ship.

The US Centers for Disease Control and Prevention (CDC) issued a statement Tuesday criticizing the quarantine efforts taken on the Diamond Princess.

"While the quarantine potentially conferred a significant public health benefit in slowing transmission, CDC's assessment is that it may not have been sufficient to prevent transmission among individuals on the ship," the CDC said.

"CDC believes the rate of new infections on board, especially among those without symptoms, represents an ongoing risk," it continued.

All American passengers and crew will not be allowed to return to the US for at least 14 days after they leave the Diamond Princess, according to a US State Department spokesperson. There are more than 100 US citizens on board the ship or in hospitals in Japan.

Late Sunday, 328 American passengers were evacuated from the ship and are now in quarantine at two US bases. Of the 14 Americans who tested positive during final screenings, 13 are being treated at the University of Nebraska Medical Center and one patient who flew into Travis Air Force Base in Northern California, is currently under isolation at a Napa County medical center.

Australia, Hong Kong, Canada and the UK are also working to evacuated their citizens off the ship.