Almost 5,000 Covid-19 cases have been linked to the music and surfing festival Boardmasters, which took place in Cornwall this month. Health officials said 4,700 people who have tested positive for coronavirus confirmed they had attended the festival in Newquay or had connections to it. About three-quarters of them are aged 16-21 and about 800 live in the county. The number of Covid infections across the south-west of England has increased but is rising sharply in Cornwall and the Isles of Scilly, with 717 cases per 100,000 of the population being infected in the seven days up to and including 19 August. Cornwall council said it had thought about cancelling Boardmasters, which took place from 11-15 August and was attended by about 50,000 people, but had decided the festival could go ahead. It insisted its staff had worked closely with the organisers to make the event as safe as possible. The festival, which featured Foals and Gorillaz, asked all ticket-holders aged 11 and over to demonstrate their Covid-19 status through the NHS Covid app before entering. Face masks were not compulsory but were encouraged. People who camped at the festival had to take a second NHS lateral flow test during the event and log their results in the app. Cornwall council’s public health team is urging all residents and visitors to make testing a priority. Rachel Wigglesworth, the director of public health for Cornwall and the Isles of Scilly, said: “Covid cases have been rising steadily across Cornwall over recent weeks – particularly in our tourist hotspots. “Big events and mass gatherings like Boardmasters are now permitted and our public health team worked closely with the organisers over many weeks to ensure the event was as Covid-safe as possible. “Our advice to residents, visitors and anyone who attended Boardmasters also remains the same – if you have Covid symptoms then isolate immediately and book a PCR test. If you have no symptoms, please continue to test twice a week with rapid lateral flow tests, which are available for free from pharmacies or can be delivered to your home.” A spokesperson for the festival said it had put in “risk management measures above and beyond national guidelines”. They said: “These included use of the NHS Covid pass as a condition of entry. The system detected over 450 people who would otherwise have been at risk of passing on the virus and as a result did not attend our Watergate Bay site or left the festival early. No event is able to eliminate risk entirely.”