There is likely to then be onwards transmission, particularly to household members.
Dr Michael Head, senior research fellow in global health, University of Southampton, said breaking the transmission would reduce the potential for Covid-19 being spread.
The start of that chain of transmission is often from an indoor crowded setting such as a pub
He said: “There is good evidence that highlights bars and restaurants as the source of an outbreak.
“There will then be onward transmission around the community, particularly with household members, but the start of that chain of transmission is often from an indoor crowded setting such as a pub.”
Dr Head noted that other sources of outbreaks have included cruise ships and international conferences.
He added: “If we can break that chain of transmission, then we reduce the potential for onward community transmission, hence the reason why there is a focus on the hospitality industry.”
Dr Head pointed to Public Health England’s surveillance report, a US CDC study where cases were more likely to have been reported by those dining in restaurants, and a study from Hong Kong which suggested a large cluster of cases was traced back to a collection of four bars.
A 10pm curfew imposed last week on pubs, restaurants and bars in England has been criticised by the hospitality sector, with the chief executive of UKHospitality, Kate Nicholls, saying Government data suggests a very small proportion of infections out of the home are related to hospitality.
Some scientists have also warned that the measures may be doing more harm than good.
Arguments suggest that the restrictions force people out onto the streets, and public transport, at the same time, creating the possibility of crowds coming together.
Experts have also said there is a risk of people turning to informal gatherings in the streets, where there is less control of behaviour.
However, Downing Street said the curfew strikes the right balance between protecting the public and allowing pubs and restaurants to continue trading.
The Government’s latest weekly surveillance report states that: “Since 10 August, people who test positive are also asked about places they have been and activities they have done in the days before becoming unwell – eating out was the most commonly reported activity in the two to seven days prior to symptom onset.
“Although this does not describe confirmed sources of infection, the information may be helpful to indicate possible places where transmission is happening.”
The eating out category includes visits to pubs and bars.
Up to 4.30am on September 24, 45,087 people testing positive, who were referred to NHS Test and Trace, reported at least one event within the enhanced contact tracing time period.
In total 87,128 events were reported. The most common event was eating out with 12,734 events – 14.6% of all those reported, followed by shopping – 11,654 events, 13.4%.
The figures represent where people had been, and not necessarily where transmission occurred.
