South West Water has advised customers in Alston and the Hillhead area of Brixham to boil their drinking water following new test results showing small traces of cryptosporidium.
Cryptosporidium is a parasite commonly found in the intestines and faeces of infected humans and animals.
It can be transmitted through contaminated water, swimming in or drinking from affected sources, as well as consuming contaminated food.
Authorities are currently investigating the source of the outbreak to prevent further spread and ensure public safety.
South West Water has issued a precautionary boil water notice across several areas in Devon, including Brixham, Boohay, Kingswear, Roseland and north-east Paignton, following the outbreak of the parasite.
Residents are urged to boil tap water for drinking, cooking and brushing teeth.
The outbreak, believed to be centred in Brixham, has led to 22 confirmed cases of cryptosporidium, with a further 70 cases under investigation.
Symptoms of the infection include diarrhoea, vomiting, stomach pains, low-grade fever, and loss of appetite, typically lasting for one to two weeks.
The company said Priority Services customers will receive bottled water deliveries, and those under the Boil Water Notice will receive a £15 payment as part of the Customer Promise for service interruptions.
