Cases of an illness caused by a microscopic parasite in a Devon harbour town could continue for a further two weeks, experts said, with businesses predicting thousands of pounds of losses as school half-term approaches. The comments came as the UK Health Security Agency confirmed that cases of cryptosporidium infection in the Brixham area had more than doubled from 22 to 46, with more than 100 others reporting symptoms of the disease. About 16,000 households and businesses in the Brixham area have been told by South West Water (SWW) not to use their tap water for drinking without boiling and cooling it first. Residents and visitors have reported falling ill and business owners spoke of their deep concern that one of their busiest times – the half-term break at the end of this month– could be wrecked. Carrie Toms, 46, the head of bookings at Harbour View guest house, said: “It has affected business, people have been very concerned about it. We’ve had a few cancellations.” Sian, who runs the Sandy Toes gift shop, said: “Lots of people are saying they won’t come down because of the water situation. Obviously I rely heavily on tourism. If I don’t have a good tourist season, I’m in big trouble.” Sally Everton, of Visit Devon, said it was a “major concern” that people would steer clear of Brixham and the wider area. Tessa Govier, 67, a senior care worker at a nursing home, said she was horrified by what had happened. “I think it’s put a lot people off coming here. I’ve heard that people have cancelled bed and breakfast bookings.” Michael Smith, co-owner of the Venus cafe at Broadsands, near Brixham, said there had been a 40% drop in business in the last two days while Wall Park touring caravan campsite said customers had contacted the park saying it was too risky to visit. SWW issued a “boil water notice” for Alston and the Hillhead area of Brixham after water tests showed “small traces” of the parasite, which causes sickness and diarrhoea. The company’s chief customer and digital officer, Laura Flowerdew, said a faulty valve was a potential source. It has not put a date on how long it believes the outbreak will last but Paul Hunter, professor in medicine and infectious disease expert at the University of East Anglia (UEA), told the BBC residents should “expect to see further cases for at least 10 days to two weeks”. The health secretary, Victoria Atkins, said there would be “very, very hard questions” for South West Water to answer over the outbreak of cases of cryptosporidium. Speaking to reporters during a visit to Exeter University, Atkins said: “There will be very, very hard questions for South West Water to answer. At the moment I think we probably need to give them the space to conduct their investigation; we know that they have identified the source. “The public will want to know how on earth that source happened, what was the chain of events that led to this, because of course we all understand the expectation that we all have when we turn our taps on is that (we get) clean drinking water and we want to be able to trust it.” Initially the company was criticised for offering £15 compensation to customers. It subsequently increased this to £115 and said it would continue to keep the level of compensation under review. Flowerdew said: “We sincerely apologise for the impact this is having on our customers in the Brixham and Alston areas. Protecting the health of our customers and providing them with a clean, fresh drinking water supply is our number one priority and we will continue to work around the clock to make sure that happens as soon as possible.” The company has set up two bottled water collection points, at Paignton and Brixham, where customers can collect bottled water. It continues to deliver bottled water for customers who cannot collect.