China and South Korea on Tuesday reported more cases of a new viral illness that has been concentrated in North Asia but is causing global worry as clusters grow in the Middle East and Europe.

New virus cases in China continued to fall Wednesday, with 1,749 more infections and 136 additional deaths as the top official in the outbreak's epicenter vowed to find and isolate every infected patient in the city by day's end.

A viral outbreak that began in China has infected more than 71,000 people globally. The World Health Organization has named the illness COVID-19, referring to its origin late last year and the coronavirus that causes it.

China on Wednesday reported another drop in the number of new cases of a viral infection and 97 more deaths, pushing the total dead past 1,100 even as the country remains largely closed down to prevent the spread of the disease.