CHIANG RAI — Health officials on Tuesday said a worker who recently rode a bus from Bangkok to his home in the north was diagnosed with coronavirus infection.

Chiang Rai provincial public health office chief Thosathep Boonthong said the city’s latest patient is a 33-year-old man who departed from Bangkok during the travel rush on Sunday, which saw at least 40,000 people leaving the capital to their hometowns.

The man was working at a bar in Thonglor area, one of the largest outbreak clusters in the country.

“The province’s third patient has a history of working at a bar in Bangkok’s Thonglor neighborhood,” Thosathep said. “He rode a bus back to Chiang Rai on March 21 before he developed a fever.”

According to a local news outlet Kao Krai Chiang Rai, the bus was bound for Chiang Saen district in Chiang Rai. It left Bangkok at 7.15pm on March 13 and was operated by Sombat Tour.

Thosathep said health officials are searching for 30-40 passengers who shared the same ride with the patient to advise them to take a quarantine for 14 days.

The country’s northernmost province reported three cases of infection as of today. Provincial deputy governor Pasakorn Boonyaluk said he is considering harsher measures to limit the movement of people, especially on those who returned from Bangkok and other high-risk areas.

All but two border crossings in the province to Myanmar and Laos have been sealed to stem the outbreak, Pasakorn said.

Avoid Travels, Gov’t Says

After the government ordered shopping malls and entertainment venues across the capital to shut down for 14 days, many workers fled Bangkok for their hometowns in the upcountry. Migrant workers also headed for border checkpoints.

The Ministry of Public Health on Saturday issued an urgent announcement calling local health officials to document profiles of those returning from Bangkok since March 22, and inform the returnees to isolate themselves for 14 days after their arrivals.

Chief of the Disease Control Department Suwannachai Wattanayingcharoenchai said the flux of people from Bangkok can spread a risk of infection to the elderly.

Bangkok governor Aswin Khwanmuang also asked people not to leave Bangkok and avoid travels during his Facebook Live address on Monday.

In a related development, the Department of Rail Transport on Tuesday made it mandatory for passengers taking trains and metros to wear face masks while using the service starting tomorrow.