A GP practice in Brighton has been closed after a staff member tested positive for the coronavirus.
Experts in protective clothing have spent the day at The County Oak Medical Centre.
Patients of the medical centre are being asked to call NHS 111 if they have any concerns.
NHS GP Dr Sara Kayat says the UK is dealing with the virus 'incredibly well'.
She says: "When you hear that the number of cases in the UK has doubled, it does sound scary, but you do have to remember that ultimately that is only 8 cases in total, out of the 40,000 plus cases. The majority, more than 99% of them, are in China.
I think we're dealing with it incredibly well in the UK and potentially the fact that we have doubled in the number of cases is because we're getting very good at contact tracing and we're getting very good at diagnosing it now."
Today (10th Feb) health officials announced four more cases in the UK.
The four people infected are all known contacts of a businessman who was diagnosed in Brighton last week and who contracted the virus at a conference in Singapore.
The same man had travelled to a ski resort in France, where a further five cases were confirmed yesterday. These cases are also linked to the businessman.
Meanwhile a school in Southampton closed for the day as a precaution, after pupils were put in isolation over coronavirus fears.
Students at St Mary's Independent School in Bitterne Park were put in isolation after being checked by medical staff at Southampton General Hospital.
The school will stay closed for deep cleaning.
As the number of confirmed cases of coronavirus in the UK rose to eight, a statement on the Department of Health website said the virus constitutes a "serious and imminent threat to public health".
The Government said Arrowe Park Hospital on Merseyside and Kents Hill Park in Milton Keynes are now designated "isolation facilities".
Both facilities are housing Britons who have returned from Wuhan on repatriation flights.
In a statement, PHE medical director Yvonne Doyle said: "As a result of our contact tracing we now know the new cases announced today are all closely linked to one another.
"Our priority has been to speak to those who have close and sustained contact with confirmed cases, so we can advise them on what they can do to limit the spread of the virus.
"Two of these new cases are healthcare workers and as soon as they were identified, we advised them to self-isolate in order to keep patient contact to a minimum.
"We are now working urgently to identify all patients and other healthcare workers who may have come into close contact, and at this stage we believe this to be a relatively small number."