Efforts are on to contact 250 delegates from across UK who attended a conference in London where they might have come into contact with the city's first coronavirus patient, a media report said on Friday.
The patient, a Chinese national, was at the UK Bus Summit at the Queen Elizabeth II Centre on February 6, the Metro newspaper said in the report.
People who attended the summit had been warned that they may have come into contact with the Chinese national at the event.
They received a letter from Public Health England saying that people with symptoms to self-isolate and contact the National health Services (NHS) helpline.
Meanwhile, two healthcare workers at Lewisham Hospital have been put into isolation for two weeks while the Uber driver has been suspended.
Nearly 800 people were tested on Thursday for the virus across the UK after the ninth confirmed case of coronavirus, also known as COVID-19.
There were fears that the disease may have spread on London Underground and people who show symptoms are being urged to stay at home.
The conference patient, who is in her 20s or 30s, lives with family in London and caught the virus in China.
She became ill after arriving in London. After being tested at Lewisham, she was sent home for three days before the test came back positive.