BANGKOK, Dec 20 (Reuters) - Thailand is considering reinstating mandatory quarantine for foreign visitors due to concerns over the spread of Omicron, as the health ministry reported on Monday the country"s first case of local transmission of the coronavirus variant. The public health ministry will propose scrapping a quarantine waiver for vaccinated visitors and revert to hotel quarantine and a "sandbox" programme, which allows free movement in specific locations, minister Anutin Charnvirakul said. The proposal was driven by worries over the spread of Omicron, Anutin told the Inside Thailand television show, adding it will be made 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 traveller, 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 coronavius test due on Wednesday, Chakrarat added.