I didn’t mean to cause hysteria. My answer was meant for Hong Kong as quoted. There may be special arrangements made if it happens, but here’s what the HK govt says happens...

https://www.coronavirus.gov.hk/eng/i...faq.html#FAQ11

What will happen if the test result is positive?
If a sample tests positive, the Centre for Health Protection (CHP) will notify the person concerned as early as possible and arrange for admission to a public hospital for treatment.
On receiving notification of confirmed cases of COVID-19, the CHP will conduct epidemiological investigation and contact tracing. Quarantine will be arranged for close contacts while medical surveillance will be arranged for other contacts.