HONG KONG/TOKYO -- A new form of respiratory virus -- originating in the central Chinese city of Wuhan -- has spread further in Asia and beyond. China's National Health Commission reported the death toll in China had reached 361 as of the end of Sunday, up by 57 from the previous day.
There were 2,829 new confirmed infections of the new coronavirus, bringing the cumulative total to 17,205.
The World Health Organization declared the spread of the virus a global health emergency on Jan. 30, though it stopped short of recommending any restrictions on travel and trade. Still, many countries are blocking the entry of people from Wuhan -- and in some instances, all of China -- to help combat the deadly virus.
On Feb. 2, the first death due to the new coronavirus outside China was confirmed in the Philippines.
Keep up to date on the latest coronavirus news here. Here are six things you need to know.
What is the coronavirus and how does it spread?
Chinese officials have confirmed that coronavirus -- which causes pneumonia -- comes from the same strain of viruses as severe acute respiratory syndrome, or SARS. Patients typically show symptoms such as fever, coughing and breathing difficulties, with acute respiratory distress syndrome in severe cases.
How the virus is transmitted among humans is unclear, but both the World Health Organization and Chinese officials regard animals as being the likely source. A research center in China suggested that there is a high chance of it originating from bats, after comparing the genome of the coronavirus with another virus found in bats.
Chinese investigators have confirmed that most of the early patients visited a seafood and wildlife market in Wuhan, which was shut down in early January. The first cases appeared last month in the city.
Is there a cure for this pneumonia?
Doctors in Thailand on Sunday announced that a treatment comprised of the flu drug oseltamivir mixed with HIV drugs lopinavir and ritonavir has significantly improved the condition of a patient from China. The doctors said she quickly improved and tested negative for the virus within 48 hours. Before the drugs were administered, the 71-year-old woman had shown no signs of recovery for 10 days after being identified as a carrier of the virus.
However, it is too early to determine whether such drug cocktails would be effective on all coronavirus carriers.
A team of scientists at the University of Hong Kong also developed an experimental vaccine for the deadly virus, but the drug would need to pass rounds of animal testing, human clinical trials and regulatory approval before it can be released on the market. The process could take at least one year even if expedited.
China announced a lockdown on Wuhan and other cities. What does that mean, and is it effective?
Chinese authorities have had a travel ban on Wuhan and dozens of other cities in Hubei Province and surrounding provinces since Jan. 23, shutting down flights, trains and highways into and out of those cities. The ban also applied to intracity transportation, including subways, buses and ferries. These unprecedented measures mean that residents in those cities -- a total of over 60 million people -- are under the largest quarantine in modern history.
Experts doubt how effective the bans will be. About five million people in Wuhan, a city of 11 million, have left the region for the Lunar New Year holiday since the outbreak was discovered, the city's mayor said on Jan. 27.
"Some people carrying the virus may not show symptoms at an early stage. They could have traveled across the country or overseas already," Guan Yi, a professor of virology at the University of Hong Kong told Caixin on Jan. 23. "I think we have already missed the golden timing for disease control."
How are foreign governments and businesses responding?
Countries are beginning to tighten controls on borders and airports as the virus spreads.
More than 60 countries and regions have restricted entry of people from mainland China. The U.S., Singapore, Philippines, New Zealand, Mongolia and Australia banned entry to noncitizens traveling from China. Japan, South Korea and Hong Kong are denying entrance to noncitizens from Hubei Province. North Korea closed its border with China in late January and Russia recently did the same.
Airlines around the globe have either reduced or completely canceled flights to the mainland.
Many companies have advised against business trips to parts of China. Telecom equipment maker Huawei Technologies postponed its annual developers' conference in the southern city of Shenzhen, which was planned for mid-February. Macao's leader, Ho Iat-seng, said in January that he "could not rule out" shutting down all the casinos in the territory if the situation worsens.
Meanwhile, countries rushed to evacuate their citizens trapped in the Hubei area after the lockdown was imposed. The U.S., Japan, South Korea, Singapore and Indonesia are among those who evacuated citizens from Wuhan. But Pakistan chose not to bring its students home, which triggered criticism from opposition parties.
What has China learned from its past experience with SARS?
China was criticized internationally for its attempt to cover up and underreport SARS cases 17 years ago. The virus eventually spread to 29 countries, resulting in over 8,400 cases of infection and 813 deaths, according to the WHO.
This time, the country appears to have responded more swiftly and proactively by identifying the pathogen in a few weeks since the first case emerged, said Gabriel Leung, a public health professor at the University of Hong Kong who led SARS studies in 2003. It has also shared the genetic sequence of the virus with health authorities around the world.
However, transparency remains a major problem. Public awareness of the new disease had been low in China until Jan. 17, when a sudden surge of infected patients was announced by local health officials. That was followed by President Xi Jinping's remark that it is "extremely crucial" to take every possible measure to combat the new coronavirus. Before that, online discussion of the virus had been muzzled, with eight people detained for "spreading false rumors."
What should people do to protect themselves?
The WHO recommends frequently washing hands with soap and water or using an alcohol-based hand rub; covering the mouth and nose with a flexed elbow or tissue when coughing and sneezing; avoiding close contact with people who have a fever and cough; and avoiding direct unprotected contact with live animals at markets.
Those who develop a fever, cough or difficulty breathing should seek medical care.
"The consumption of raw or undercooked animal products should be avoided," the WHO also says. "Raw meat, milk or animal organs should be handled with care, to avoid cross-contamination with uncooked foods, as per good food safety practices."
Additional reporting by Dean Napolitano in Hong Kong and Katsuhiko Hara in Tokyo.