NHS Ayrshire and Arran has called on customers who were in The BUF bar in Prestwick between May 22 and 30 to get tested.
Those with symptoms are asked to self-isolate immediately and book a test, while people with no symptoms can visit an asymptomatic or mobile testing site.
The health board is also carrying out contact tracing and undertaking a risk assessment to identify people who may have had contact with confirmed cases.
These people and their households are being contacted and told to self-isolate for 10 days and book a PCR test.
NHS Ayrshire and Arran said in a statement: “All relevant public health measures are in place and our Public Health Team is working with The BUF management team and South Ayrshire Environmental Health Officers to manage and monitor the situation.
“As a precautionary measure, The BUF has voluntarily closed until contact tracing is complete.”