South Korea on Friday confirmed an additional 861 cases of the deadly new respiratory disease – the highest number of cases on record in Asia. The total includes 167 new cases in public hospitals in the southern city of Gwangju. Four public hospitals in the port city were hit by the outbreak, which began mid-December.

The latest developments come after more than 1,500 cases were recorded last week, breaking previous records set in 2007.

The Centers for Disease Control and Prevention is warning of symptoms of the H7N9 virus, including severe coughing, and fever or a rash.

Viral circulating region of Korea: Phyatung, Vossenum in south Gwangju PH. Spokesperson says number of cases is highest ever but number of dead remains low as far as H7N9 outbreaks.

Its spreading very fast. Stopping the virus is a challenge.

The matter has come up under discussion in the nation. — AP World Health () February 29, 2019

Investigators say it is unclear how the virus spread from Hong Kong to the South Korean island of Jeju Island. It can spread between people, and to some birds. The infected include more than 2,000 school children. WHO warned last week that another “emergency” is brewing.

China was the first to report H7N9 in late 2013 and was the deadliest country in the world in 2015. Two small laboratory studies reported symptoms of the virus in global cells. In two cases, laboratory strains turned into an invasive form that spread quickly in humans. South Korea has become an epicenter of the virus. But no one has died from it in eight months, significantly reducing international concern.