Medical clinics across Brisbane have been asking patients and staff to wear masks as they prepare for widespread COVID-19 transmission.

Currently, masks are only mandated in airports and on domestic flights, but it's recommended that Queenslanders keep a mask with them in case they can't physically distance.

Queensland's Chief Health Officer says health authorities were "actively considering" reimposing a mask mandate as community transmission increases, and encouraged people to wear them indoors and on public transport.