The former Portuguese colony has only one public hospital and its medical system was already stretched before the outbreak.
Macao follows China’s “zero-COVID” policy of stamping out all outbreaks at just about any cost, which runs counter to a global trend of trying to co-exist with the virus.
COVID-19 testing for all will be done at least twice this week, with antigen rapid tests (ART) also required in between.
The six casino operators, Sands China, Wynn Macau, MGM China, Melco Resorts, Galaxy Entertainment and SJM Holding, are racking up losses ahead of bids for new licenses by next month.
Still, daily infections are fewer than elsewhere, such as neighbouring Hong Kong, where cases have jumped this month to more than 3,000 a day as curbs have started to ease.
But Macao has an open border with China, and many residents live and work in the adjoining city of Zhuhai.