A 62-year-old man returning home from the US was diagnosed with the variant, though at this time, he remains asymptomatic.

In a statement, Macau’s Novel Coronavirus Response and Coordination Centre said the man was tested immediately on arrival, which returned a positive result for Covid-19. A sample was then sent for viral genome sequencing, which flagged his infection as Omicron.

The man reportedly flew from Los Angeles to Singapore on Christmas Day and from there, took a connecting flight to Macau.

Due to his asymptomatic nature, his condition has not been added to the city’s running tally of confirmed cases. Since the start of December, Macau has separately recorded asymptomatic cases.

This comes after a 23-year-old resident studying in the US tested positive for the variant after arriving in the city on 26 December. When news of Omicron’s arrival in Macau broke, Hong Kong shares of companies with operations in the East Asian gambling hub tumbled.

Sands China and Galaxy Entertainment suffered drops of over 2%, and this latest development is a further blow to businesses based in the city.

Health authorities reiterated that the Omicron variant is highly infectious and cautioned residents against overseas travel unless absolutely necessary.

Macau has also retained hefty travel restrictions, with non-resident visitors barred from entering the city, while all residents arriving from overseas are subject to a quarantine regardless of whether or not they test positive.

Neighbouring Hong Kong was a significant source of gamblers before the pandemic, but it has been hit especially hard by the new variant, with the city’s Centre for Health Protection reporting 70 cases of Omicron detected so far.