Due to fears about the spread of Omicron, Thailand is considering restoring strict quarantine for foreign visitors, according to the health ministry, which announced the country’s first instance of local transmission of the coronavirus variation on Monday.

According to minister Anutin Charnvirakul, the public health ministry would propose eliminating a quarantine waiver for vaccinated travelers and reverting to hotel quarantine and a “sandbox” scheme, which permits free mobility in specific areas.

Concerns over the spread of Omicron prompted the suggestion, according to Anutin, who added that it will be presented to the government’s COVID-19 taskforce “soon.”

The minister’s remarks come after Thailand reopened to foreign visitors in November, ending nearly 18 months of strict entry policies that contributed to a collapse in tourism, a key industry and economic driver that drew 40 million visitors in 2019.

Thailand had detected 63 people infected with the Omicron variant so far, Anutin said, with one case of local transmission and the rest imported cases.

The first locally transmitted case was found in a Thai woman who tested positive to Omicron after contracting the virus from her husband, a Colombian who returned to Thailand from Nigeria in late November, a health ministry official told a daily briefing.

“She is potentially the first in Thailand to get Omicron from an overseas traveler, her husband, and the first locally transmitted case,” said Chakrarat Pittayawonganon, an official from the Disease Control Department.

Both the husband and the wife had been fully vaccinated with the AstraZeneca vaccine, he said.

The couple had one high-risk contact, a taxi driver, who was being quarantined and pending a second coronavirus test due on Wednesday, Chakrarat added.