Residents in South Devon have been urged to boil their tap water following reports of people falling ill to a waterborne disease.

Up to 16 cases of cryptosporidium have so far been confirmed, along with 70 suspected incidents in Brixham. Some unconfirmed press reports have claimed hundreds have fallen sick.

The disease, predominantly caused by a waterborne parasite, includes symptoms such as mild to severe diarrhoea, vomiting and fever.

People can become infected if they swallow infected food or water, which would also include a person swallowing water while swimming (the parasite is resistant to chlorine disinfection).

The UK Health Security Agency (UKHSA) said it was working with South West Water (SWW), NHS Devon, Torbay council and the Environment Agency (EA) to investigate the cases.

In a statement, Sarah Bird, UKHSA’s consultant in health protection in the South West, said that those affected “should stay off school and work for 48hrs since the last episode of illness and away from swimming pools for 14 days after the last episode of illness”.

Chris Rockey, from SWW, was quoted by the BBC, saying the water company would continue to work with “health professionals and monitor the water”.

SWW has in the meantime urged residents across Brixham, Kingswear, Roseland, Boohay and north east Paignton to boil their tap water before drinking it, or cleaning or cooking with it.

The water company released a statement this morning, saying it had found “small traces of the organism...overnight and this morning”, adding that it was working with the public health authorities to urgently investigate the source.

It said: “The data from our tests over the last several weeks showed that the treated water leaving our treatment works was not contaminated. However, in the Hillhead section of our network further tests taken overnight and working with the advice of UK Health Security Agency we have found small traces of cryptosporidium and are therefore issuing the boil water notice.”

SWW has also announced that bottled water stations “will be set up in the affected areas as soon as possible”.

However, SWW was criticised for its initial response to the incident a day earlier, when it dismissed social media posts expressing concern about drinking water quality by saying the supply was fine “to use as normal”.

Totnes and South Devon MP, Anthony Mangnall, highlighted the discrepancy, saying: “It is extremely frustrating that South West Water weren’t quicker to respond to reports of illness, and they initially denied that it was anything to do with their network.

“I will continue to make sure South West water cleans up their act, provides support for residents and sorts this out once and for all.”

Video posted today by the Brixham (Fish Town) group on Facebook shows at least 12 SWW vans in a car park, reportedly waiting to hand out bottled water.

The incident comes less than two days after the government announced four new bathing sites in the River Dart Estuary.