There are some indications that the incubation period for the coronavirus could be longer than 14 days, with patients testing positive after much longer quarantine periods, researchers said. The rush to understand the virus came as infections rose in South Korea, Japan, Iran and Italy. The head of the World Health Organization warned that the window for stopping the epidemic was narrowing. Here’s what we know:

● Chinese leader Xi Jinping has been advised that the situation in Wuhan “remains grim and complex.” Amid an alarming surge in cases with no clear link to China, infectious disease experts say they believe the flu-like illness may soon be a pandemic and impossible to contain.

● South Korea and Japan both reported a sharp spike in cases, with the number of cases in South Korea rising to at least 556. A sixth person died in Iran from the virus, while Italy has at least 76 confirmed cases, making it the largest hot spot in Europe.

● Nine South Korean tourists who recently toured Israel and the occupied West Bank tested positive for coronavirus Saturday. Israeli and Palestinian authorities are urging anyone who may have come in contact with them to report and self-isolate.

● China on Sunday local time reported 648 new cases and 97 additional deaths. There continues to be a great deal of skepticism about China’s numbers as the criteria for diagnosing coronavirus keep changing.

● Thousands of Russian-linked social-media accounts are leading a disinformation campaign to cause alarm about the outbreak, the AFP reported.


BEIJING — Scientists were studying a case in China that suggested the incubation period for coronavirus could be longer than 14 days, potentially casting doubt on current quarantine criteria even as the epidemic moved into new regions.

The potential for a longer incubation period was linked to a patient in China’s Hubei Province, where the virus was first detected in December. A 70-year-old man was infected with coronavirus, but did not show symptoms until 27 days later, the local government reported.

South Korea and Japan both reported a sharp spike in cases Saturday, while an additional 97 people died of the virus in China, and a sixth person died in Iran. Italian authorities Saturday said the country was seeing a sudden rise in coronavirus cases, with at least 58 confirmed in the past two days — an outbreak that represents the largest across Europe.

Meanwhile, scientists in China reported indications that the virus might be transmissible through urine.

Almost 78,000 people worldwide have been diagnosed with the coronavirus, with the vast majority of cases located in mainland China, according to the World Health Organization. Roughly 1,400 cases have been tallied outside China.

WHO Director General Tedros Adhanom Ghebreyesus said Saturday that WHO experts were due to arrive that day in Wuhan, China, the center of the coronavirus outbreak. The team has visited three Chinese provinces this week, Tedros said in a speech in Geneva.

Outside China, Tedros said that the WHO is concerned about the number of cases without a clear epidemiological link, such as recent travel to China or contact with a person known to be infected.

The organization also has been sending medical supplies to Africa and training the continent’s health-care workers to prepare them for the virus’s possible arrival there, Tedros said. The only confirmed case of the coronavirus in Africa is in Egypt.

“Our biggest concern continues to be the potential for covid-19 to spread in countries with weaker health systems,” Tedros said.

Chinese leader Xi Jinping, who has not visited Wuhan since the outbreak began, was briefed that the situation in the city and in surrounding Hubei province “remains grim and complex,” according to a report by the official Xinhua News Agency published Saturday.

“The nationwide inflection point of the epidemic has not yet arrived,” the report said after a meeting of Communist Party leaders.

China’s National Health Commission reported Sunday local time that 648 new cases of coronavirus were diagnosed Saturday, taking the total to nearly 77,000. The rate of infection outside Hubei appears to have slowed markedly, although there has been a great deal of confusion about the statistics this week as officials have repeatedly changed the criteria for confirming cases.

Authorities discovered Friday that a 70-year-old man in Hubei was confirmed as infected after 27 days in isolation, while a man in Jiangxi province tested positive after 14 days of centralized quarantine and five days of isolation at home. On Thursday, authorities reported that a man in Hubei had tested positive for coronavirus after what appeared to be a 38-day incubation period with no symptoms.

The United States is also struggling with domestic fallout from its responses to the virus. The Californian city of Costa Mesta has sued the federal government over its plan to transfer quarantined coronavirus patients from the Travis Air Force Base near Sacramento to the former Fairview Developmental Center as early as this weekend. The city said that the area in question is surrounded by residential neighborhoods and that placing patients with a highly contagious disease so close by could pose a risk to public health.

A federal judge granted Costa Mesa’s request Friday, temporarily blocking the transfer of up to 50 patients. The restraining order prohibits state and federal government authorities from transporting anyone infected with coronavirus or who has been exposed to the disease to Costa Mesa before a hearing at 2 p.m. Monday at the Santa Ana federal courthouse, according to the Los Angeles Times.

The State Department, meanwhile, is battling thousands of Russian-linked social-media accounts promoting baseless theories that the United States created the coronavirus outbreak, according to the AFP. The accounts post “almost near identical” messages at similar times in five languages, the report says.

U.S. officials said they discovered the disinformation campaign in mid-January.

“Russia’s intent is to sow discord and undermine U.S. institutions and alliances from within, including through covert and coercive malign influence campaigns,” Philip Reeker, the acting assistant secretary of state for Europe and Eurasia, told the AFP.

Misinformation about the coronavirus outbreak has proliferated — mostly on social media — since the first cases were reported in December.

Coronavirus cases in South Korea skyrocket; cases triple in Japan

The State Department on Saturday heightened its travel advisories from Level 1 to Level 2 for South Korea and Japan, urging Americans to “exercise increased caution” when traveling to those countries due to the rising number of coronavirus cases there. Older adults and people with chronic conditions, who might be at higher risk of contracting the virus, should consider postponing unnecessary travel to those countries, the department said.

The Korea Centers for Disease Control and Prevention (KCDC) reported Sunday that 123 additional cases of the coronavirus had been detected, taking the total to 556. This makes it the worst-affected country outside China.

“Apart from the Diamond Princess cruise ship, [South] Korea now has the most cases outside China, and we’re working closely with the government to fully understand the transmission dynamics that led to this increase,” Tedros said.

Nearly two-thirds of the new cases have been traced to existing clusters at a church in the southern city of Daegu and a hospital in nearby Cheongdo County, according to the KCDC.

More than half of South Korea’s cases are connected to the Daegu branch of the Shincheonji Church of Jesus the Temple of the Tabernacle of the Testimony.

Since members of the church attended a funeral at nearby Cheongdo Daenam hospital, at least 111 coronavirus cases have been reported there, including two patients who died of the virus.

The mass infection at the hospital is centered on its locked psychiatric ward, where a confined environment could have aggravated transmissions, said Jung Eun-Kyeong, director of the KCDC.

A 57-year-old patient at Daenam hospital died of the coronavirus, state-affiliated Yonhap News Agency reported early Sunday local time. The man is the fourth person to die of the virus in South Korea, according to Yonhap’s report, which The Washington Post could not immediately verify independently.

In Japan, the number of coronavirus cases rose to 121 on Saturday, more than tripling in a week. That number excludes the 634 people on board the Diamond Princess who contracted the virus.

One of the latest cases was a teacher in her 60s at a public junior high school east of Tokyo, who complained of nausea while working. The mayor of Chiba city said the school will be closed until Wednesday, public broadcaster NHK reported.

The teacher had not traveled abroad in the past two weeks and has no record of having been in contact with a known infected person, underlining the fact that the virus is now spreading almost invisibly throughout the country, experts say.

Italy and Iran impose new measures to contain sudden spike

As numbers suddenly rose in Italy, the government has scrambled to contain the new outbreak, asking some 50,000 people to stay indoors and suspending all public events — including religious ceremonies and school — in 10 small towns to the south of Milan.

Until a few days ago, Italy had seen only three confirmed infections, including a pair of Chinese tourists.

“There is quite an evident contagion, a very strong one,” said Giulio Gallera, health chief of the northern Lombardy region, which has seen the majority of the cases.

Italian officials Friday attributed the country’s first death to the coronavirus, and Saturday said that a 77-year-old woman had also tested positive for the virus after being found dead in her home. But Italian authorities said the woman suffered from other health conditions, and were unsure if it was the virus that had killed her.

The cases in Italy appeared concentrated in the prosperous Lombardy region, which includes the country’s financial hub, Milan, and other areas nearby.

According to Italian media reports, one of the first people to come down with the virus was a 38-year-old who’d had dinner with somebody who had just come back from China. But some three weeks passed between that dinner and the time the man came down with a fever. In between, he ran a half-marathon, played soccer and traveled to several towns, according to La Repubblica, a major Italian daily.

Meanwhile, the number of confirmed cases of the virus in Iran has risen to 29.

The outbreak there has been centered on the holy Shiite city of Qom, where on Wednesday authorities suspended schools and religious gatherings as a precaution. On Saturday, Iranian authorities also closed schools in the capital, Tehran, and issued a temporary ban on cinemas and art-related events across the country, state-run Fars News Agency reported.

Other countries in the region have also reacted with alarm, particularly after Lebanon’s first coronavirus case Friday was found to be a woman who had just traveled from Qom.

In the past few days, Iraq and Kuwait suspended direct flights to Iran, while Iraq temporarily halted new visas for Iranian nationals and, along with Turkey, imposed restrictions on travelers who had recently arrived from Iran. Kuwait Airways said Saturday that it would be chartering special flights to evacuate citizens from Mashhad, Iran.

As fears mounted, Israel announced Saturday that nine South Koreans who had recently returned home from a tour in Israel tested positive for the virus. Israeli and Palestinian authorities on Saturday urged anyone who may have interacted with the group visiting from Feb. 8 to 15 to self-quarantine as they work to trace who may have had contact with the tourists, who visited major cities including Jerusalem.

Israel’s ambassador to China, Zvi Heifetz, was among those who self-quarantined, the Jerusalem Post reported, citing Israel’s foreign ministry. Heifetz took the same flight to Seoul as the South Korean tourists and is quarantined in Beijing, the report says.

Roughly 200 students and teachers who came into contact with the South Koreans have also self-quarantined, according to the Times of Israel.

A spokeswoman for Israel’s Population and Immigration Authority said Saturday that all non-Israeli citizens arriving on a direct flight from Seoul to Tel Aviv that evening would be denied entry. Israel’s Health Ministry has ordered Israelis returning from South Korea to self-quarantine.

Efforts to clear the Diamond Princess cruise ship continue

Meanwhile, tests are continuing on the crew members on board the Diamond Princess. At least 74 crew members have so far been found to have the virus.

All of the passengers have now been tested and almost all have left the ship, either to go home if they tested negative, to local hospitals or government facilities if they have the virus, or back to their home countries.

Some passengers were asked to stay on board to serve an additional quarantine if their cabin mate contracted the virus, but they are also disembarking Saturday to serve out the rest of their quarantine in a government facility, local media reported.

More than 200 port calls in Japan by international cruise ships have been canceled since the beginning of February due to the coronavirus outbreak, a Kyodo News survey showed Saturday, with the lost revenue from passengers coming ashore dealing another blow to Japan’s weak economy.

American woman in Malaysia declared free of coronavirus

The 83-year-old woman who tested positive for the coronavirus when she arrived at Kuala Lumpur airport after disembarking in Cambodia from the MS Westerdam cruise ship has recovered, Malaysia health authorities said Saturday.

The woman “is showing good improvement and signs of recovery, however, she is still being monitored and managed in hospital for a slight cough,” Malaysia’s director general of health, Noor Hisham Abdullah, said in a statement.

The woman repeatedly tested negative while on board the ship and when she disembarked in Sihanoukville, then twice tested positive while transiting in Kuala Lumpur airport on Feb. 15. That set off a global scramble to track the hundreds of other passengers who had also disembarked then boarded planes bound for home.

The woman was taken to a hospital and given antiviral treatment and supplementary oxygen, and she showed improvement after 72 hours of treatment initiation, Abdullah said. Two more tests, conducted 24 hours apart, both came back negative for coronavirus.

But the Centers for Disease Control and Prevention cast doubt on whether the woman was ever infected, saying she “never had coronavirus to our knowledge.”

Cambodia’s Ministry of Health had previously cleared the 747 crew members who were still on board the Westerdam and the 781 passengers who were still in the country of coronavirus infection.

Chinese scientists isolate coronavirus strains in urine

Separately, scientists in China are continuing to study how the virus is transmitted.

A research team led by renowned Chinese pulmonologist Zhong Nanshan had isolated live coronavirus strains in urine samples from infected patients, Zhao Jincun, a respiratory expert at the State Key Laboratory, told reporters in Guangdong on Saturday.

The team of scientists had previously said the virus, in addition to being carried in respiratory droplets, appeared to be transmissible through fecal matter, underscoring the need to practice good hand washing as a preventive measure.

Zhao did not directly say that the virus could be transmitted through urine, simply noting that the strains had been isolated and that this had implications for public health control. They are continuing to work on isolating the virus and on a cure, the Guangzhou Daily reported.

But he said people should pay more attention to personal and family hygiene to prevent the spread of the virus and recommended frequently washing hands, closing the toilet lid before flushing and making sure bathroom drains are not blocked.

Denyer reported from Tokyo, Chico Harlan from Rome, and Miriam Berger and Marisa Iati from Washington. Lyric Li in Beijing, Akiko Kashiwagi in Tokyo, Min Joo Kim in Seoul, Stefano Pitrelli in Rome, Ruth Eglash in Jerusalem, and Yasmeen Abutaleb and Carol Morello in Washington contributed reporting.