People in masks cross a road in Chinatown in Singapore on Jan 31, 2020. (WEI LENG TAY / BLOOMBERG)

Coronavirus cases in South Korea and Malaysia tied to a business meeting in Singapore attended by visitors from China have prompted an investigation into the infection’s international spread.

A 41-year-old man in Malaysia and two people in South Korea were infected with the so-called 2019-nCoV virus after attending a meeting at a Singapore hotel in the third week of January, health authorities said. The World Health Organization is coordinating with Singapore’s Ministry of Health in relation to the event, said Olivia Lawe Davies, the agency’s Manila-based regional communications manager.

“Based on current information, there is not evidence of effective and sustained community transmission,” Lawe Davies said in an email Wednesday. “As countries are stepping up surveillance, the detection of more cases of local transmission can be expected.”

The event in Singapore has been tied to only the confirmed 2019-nCoV cases in South Korea and Malaysia, and the source of their infections hasn’t been identified.

Based on current information, there is not evidence of effective and sustained community transmission

Olivia Lawe Davies, Manila-based regional communications manager, WHO

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Grand Hyatt

The Malaysian man was in Singapore from Jan 16 to 23 for a meeting at the Grand Hyatt at which Chinese nationals were also present.

He became unwell after his return to Malaysia, the country’s Health Minister Dzulkefly Ahmad told reporters Tuesday.

The luxury hotel, located off Singapore’s Orchard Road shopping strip, hasn’t been advised on how, where and when the Malaysian man was infected, and the hotel wasn’t aware of any other confirmed or suspected cases among the hotel’s guests or colleagues, it said in a statement Wednesday.

The hotel, which says it has 677 guestrooms and suites, has implemented “deep-cleaning measures” in public areas, restaurants, meeting spaces and guestrooms, and has shared a comprehensive guide about novel coronavirus with Hyatt hotels globally on procedures to protect against transmission of the virus, according to the statement.

Singapore’s Ministry of Health said it’s investigating the case and trying to identify individuals who had close contact with him.

Left Singapore

“The particular risk exposure was quite some time ago,” Kenneth Mak, the city-state’s director of medical services, told reporters Tuesday. “There is a possibility that many of the people that took part in this particular meeting may not be in Singapore anymore.”

South Korea announced two cases related to the event. The first, a 38-year-old man, was in Singapore from Jan 18 to 24, the country’s center for disease control said. He requested to be tested for the virus Tuesday after learning about the Malaysian case, the center said in a statement. The man was confirmed to have the virus Wednesday.

Later the same day, the center said a 36-year-old man who also attended the Singapore event had been confirmed with the virus. He was the nation’s 19th case.

Singapore reported its first local transmission of the virus Tuesday, with four cases that involved human-to-human transmission in the city, bringing the total number of reported cases to 24. The infections have cast a shadow over the city’s conference and exhibitions industry, a major contributor to the economy.

Event organizer SingEx Exhibitions said on Wednesday its annual health care conference CAREhab 2020, originally scheduled for Feb 14-15 at the Singapore EXPO conference and exhibition center, would be pushed back to July 10-11.

READ MORE: Coronavirus: When will the cure be ready?

Air Show

Singapore is due to host one of its biggest industry events next week -- the biennial Singapore Air Show. The show, which attracts more than 1,000 aerospace companies from around the world, has canceled its key Aviation Leadership summit, but said the air show will go ahead.

Singapore has stepped up testing at hospitals and is running a public health campaign to try to reduce the chance of spreading the virus and has suspended school assemblies, large-group activities for pre-schools and facilities for the elderly.

The government said that, if the virus spreads to the broader community, it is ready to take additional measures, including canceling mass gatherings, suspending schools and limiting non-essential care services.