Coronavirus Live Updates: South Korea Reports 800 New Cases

South Korean officials have warned that confirmed cases would rise sharply as they aggressively tested thousands of people, particularly in the southeastern city of Daegu. More than 86 percent of patients have been in Daegu and nearby towns; many have been associated with a church called Shincheonji, which has a strong presence in Daegu.

The United States military, which has more than 28,000 personnel in South Korea, said on Saturday that the spouse of an American soldier infected with the virus had also tested positive for it. She had been in self-quarantine since Wednesday, following her husband’s diagnosis, and was being transported to a military hospital, the military said.

Also on Saturday, Mr. Kim, North Korea’s leader, convened the Politburo of his ruling party to order an all-out campaign to prevent an outbreak, state media reported. The North has not reported any coronavirus cases, but there has been concern that the secretive, totalitarian country could be hiding an outbreak.

“In case the infectious disease spreading beyond control finds its way into our country, it will entail serious consequences,” the North’s official Korean Central News Agency quoted Mr. Kim as saying. It said that officials had discussed “measures to deter the influx and spread of the infectious disease in a scientific, preemptive and lockdown way.”

  • Updated Feb. 26, 2020

    • What is a coronavirus?
      It is a novel virus named for the crownlike spikes that protrude from its surface. The coronavirus can infect both animals and people and can cause a range of respiratory illnesses from the common cold to more dangerous conditions like Severe Acute Respiratory Syndrome, or SARS.
    • How do I keep myself and others safe?
      Washing your hands frequently is the most important thing you can do, along with staying at home when you’re sick.
    • What if I’m traveling?
      The C.D.C. has warned older and at-risk travelers to avoid Japan, Italy and Iran. The agency also has advised against all nonessential travel to South Korea and China.
    • Where has the virus spread?
      The virus, which originated in Wuhan, China, has sickened more than 80,000 people in at least 33 countries, including Italy, Iran and South Korea.
    • How contagious is the virus?
      According to preliminary research, it seems moderately infectious, similar to SARS, and is probably transmitted through sneezes, coughs and contaminated surfaces. Scientists have estimated that each infected person could spread it to somewhere between 1.5 and 3.5 people without effective containment measures.
    • Who is working to contain the virus?
      World Health Organization officials have been working with officials in China, where growth has slowed. But this week, as confirmed cases spiked on two continents, experts warned that the world was not ready for a major outbreak.

North Korea has already closed its 930-mile border with China, where the coronavirus emerged, and its border with Russia. But the Chinese border has long been porous for smugglers, who ferry goods across the shallow river that separates the countries. The North has also suspended all flights and trains to and from China and asked all foreign diplomats not to leave their compounds.

The state media report Saturday also said that Mr. Kim had fired one of his top aides, Ri Man-gon, and another official for corruption, but it was unclear whether the dismissals were connected to the antivirus campaign.