As China reported a continued slowdown in new coronavirus cases, world health officials praised the country's response while alerting other governments to be ready to aggressively react when cases appear within their borders.

Chinese health officials said Wednesday there were 406 new cases, almost all of them in Hubei province which has been the center of the outbreak. Of the 52 new deaths, all were in Hubei, an area that has been on lockdown for weeks to prevent the virus from spreading to other areas.

Bruce Aylward, who led a joint World Health Organization-China mission on the virus, said at a news conference that his team concluded China's response "changed the course of this outbreak" and may have prevented hundreds of thousands of people in the country from becoming infected.

"What was a rapidly escalating outbreak has plateaued and then come down faster than one would have expected if we had looked at the natural dynamics of an outbreak like this," Aylward said.

With cases in more than 30 countries, including new ones in Europe and the Middle East this week, Aylward said governments must be thinking about rapidly identifying cases that emerge, searching out people who have been in contact with those patients, and using isolation to prevent virus spread.

The message he wants governments to send to citizens: "They should be washing their hands now."

The WHO has several other recommendations for people to stay healthy, including maintaining a distance of at least one meter from anyone who is coughing or sneezing and avoiding touching eyes, nose or mouth. For those who are coughing or sneezing, the WHO says they should cover their mouth with a bent elbow instead of their hands, and those who experience a fever, cough and difficulty breathing should seek medical care.

While China has been hit hardest by far, there have been some 2,700 cases in other countries with more than 40 deaths.

South Korea reported its number of cases rose to 1,261 Wednesday with 11 deaths. The U.S. military said Wednesday one of its soldiers stationed in South Korea tested positive for the virus and was in quarantine.

Most of South Korea's cases have been isolated to the Daegu area, and officials are moving ahead with efforts to test more members of a church whose members make up a large portion of those cases.

Elsewhere there is concern about Italy and Iran, from which cases in recent days have been traced to new infections in parts of Europe and the Middle East.

Italy has more than 300 cases and 10 deaths. Algeria's health ministry said Tuesday that an adult Italian had tested positive after arriving in the country last week. That is the African continent's second case following one in Egypt earlier this month.

Iran has reported 19 deaths among 139 cases. Among those in the region that have tied smaller outbreaks to people who traveled from Iran are Kuwait, which reported Wednesday its 18th case, and Bahrain where the state news agency reported 26 cases.

The U.S. Centers for Disease Control and Prevention says so far cases there involve only people who contracted the virus abroad, or who have close contacts with someone who visited Hubei, China.

The officials said that while there is no so-called community spread, or instances of people being infected without knowing how or where, now is the time for communities, businesses and hospitals to figure out how to stop the virus from spreading.

"It's not so much a question of if this will happen anymore, but rather more of a question of exactly when this will happen and how many people in this country will become infected and how many of those will develop severe or more complicated disease," said CDC Principal Deputy Director Anne Schuchat.

Worries about the economic effects of the virus have rattled global stock markets this week.

Markets in Asia closed down about 1% Wednesday, while British, French and German indexes traded lower. U.S. markets saw a 3% drop in Tuesday trading.

Health officials say the coronavirus is highly infectious and kills about 2% of its victims, compared with the ordinary flu, which has a 0.1% mortality rate.