China reported 1,886 new virus cases and 98 more deaths in its update Tuesday on a disease outbreak that has caused mild illness in most people, an assessment that promoted guarded optimism from global health authorities.

The update raised the number of deaths in mainland China to 1,868 and the total confirmed cases to 72,436.

A study by the Chinese Center for Disease Control and Prevention found more than 80% of the cases studied were mild and the number of new infections seemed to be falling since early this month. World Health Organization Director-General Tedros Adhanom Ghebreyesus said it was too early to know if the reported decline would continue, however. “Every scenario is still on the table,” he told a news conference.

The seeming drop in the number of cases follows a large spike last week after hard-hit Hubei province began counting cases by doctors’ diagnoses without waiting for laboratory test results. Health authorities there said the change was meant to get patients treated faster.

The disease named COVID-19 emerged in December in Wuhan, Hubei’s capital, and the surrounding region has been put under lockdown to try to contain the outbreak. Transportation has been halted, thousands of hospital beds have been added, and military doctors and nurses have been deployed to staff facilities in the overwhelmed local health-care system.

Despite strict rules on use of masks and safety suits, medical workers have been among the victims, particularly in the early stage of the outbreak.

On Tuesday, the Wuhan Municipal Health Commission said the director of Wuhan’s Wuchang Hospital, Liu Zhiming, had died of COVID-19.

Liu had taken part in the battle against the virus from the start and had made “important contributions in the work of fighting and controlling novel coronavirus,” the notice said.

During that process, “unfortunately he became infected and passed away at 10:54 Tuesday morning at the age of 51 after all-out efforts to save him failed,” it said.

Earlier this month, public outrage was stirred by the death from the virus of Wuhan doctor Li Wenliang, who had been threatened by police after releasing word of an outbreak of unusual respiratory illness in December before it had spread widely and the city was placed under quarantine.

China may postpone its biggest political meeting of the year to avoid having people travel to Beijing while the virus is still spreading. The standing committee for the National People’s Congress will meet Feb. 24 to deliberate postponing the annual event due to start March 5.

One of the automotive industry’s biggest international events already is being postponed. Auto China 2020 had been set for April in Beijing, and its postponement adds to the many sports and entertainment events that have been delayed or canceled.

The Chinese CDC’s study examined 44,672 cases of the disease that were confirmed in China as of Feb. 11. Severe symptoms such as pneumonia occurred in 14% of them and critical illness in 5%. The fatality rate was 2.3% — 2.8% for males versus 1.7% for females.

The death rate is lower than for SARS and MERS, diseases caused by coronaviruses related to the one that causes COVID-19. But the new virus ultimately could prove more deadly if it spreads to far more people than the others did. The COVID-19 cases include relatively few children, and the risk of death rises with age or other health problems and was higher in Hubei province versus elsewhere in China.

The study warned that while cases seem to have been declining since Feb. 1, that could change as people return to work and school after the Lunar New Year holidays, typically the biggest travel period for Chinese travelers. Beijing and other governments have sought to forestall that by extending the holiday break, encouraging telecommuting and self-quarantines and conducting health checks on travelers.

Travel to and from the worst-hit central China region was associated with the initial cases of COVID-19 confirmed abroad. But Japan, Singapore and South Korea have identified new cases without clear ties to China or previously known patients, raising concern of the virus spreading locally.

The largest number of cases outside China is among passengers and crew of the Diamond Princess cruise ship quarantined at a port near Tokyo. The Japanese Health Ministry has tested 1,723 people among the 3,700 initially on board, and 454 have tested positive.

The U.S. evacuated 338 American passengers, with most of them placed in a 14-day quarantine at military bases in California and Texas. Thirteen who tested positive for the virus were taken to hospitals in California and Nebraska, and the U.S. Centers for Disease Control and Prevention said any more passengers who show symptoms will be taken to a hospital.