The toll in the Wuhan coronavirus outbreak rose to 25 on Thursday, Chinese officials have said. China’s National Health Commission said the virus has infected 830 people so far and most cases are in the city of Wuhan, Reuters reported. People in at least nine other countries were found infected with the virus, but these cases were not fatal.

The coronavirus emerged from Wuhan in Hubei province of China and has led to an outbreak. All those infected were residents of Wuhan or recent visitors to the city. The virus has spread beyond China’s borders, raising concerns of a pandemic. The coronavirus is part of the same family as the severe acute respiratory syndrome, or SARS, and the Middle East respiratory syndrome, and has spread to Thailand, South Korea, Japan, Taiwan, Hong Kong, Macau, the United States, Singapore, Vietnam and Saudi Arabia. A nurse from Kerala working in Saudi Arabia has been infected too.

The outbreak has cast a shadow over Lunar New Year celebrations. Hundreds of millions of people in China are expected to travel over the course of the new year period, which begins Saturday, both within the country and overseas. Health officials fear this travelling could spread the transmission.

However, the World Health Organization said the disease was not yet a global health emergency. It was a “bit too early” to consider the outbreak a “Public Health Emergency of International Concern,” WHO Emergency Committee panel chair Didier Houssin said.

“Make no mistake, though, this is an emergency in China,” WHO chief Tedros Adhanom Ghebreyesus said. “It has not yet become a global health emergency. It may yet become one.”

Several countries have stepped up medical screening of travellers from China, particularly those from Wuhan. Passengers from China are facing screening measures at five US airports and a host of transport hubs across Asia, including seven airports in India. European airports from London to Moscow have also stepped up checks and Nigeria, which has many citizens working in China, said it would start checks at entry points.

Meanwhile, authorities in the US are investigating a second suspected case of Wuhan coronavirus in Texas, according to AFP. Brazos County, just northwest of Houston, “is investigating a suspected case of the 2019 Novel Coronavirus,” its health authority said. The student is aged between 20 and 30 years and returned to the US from Wuhan days before screening began at US airports.

“The person presented to an area emergency department yesterday mostly out of concern, not out of symptoms,” local health official Eric Wilke said, adding that they were now being kept isolated at home. A man in his 30s, living near Seattle, was the first case in the US. He is now recovering, authorities said.