THE threat of a hidden disease pouring from Leigh's taps has sparked a call for a public debate on the region's water supplies.

The North West director of public health, Prof John Ashton, has made the appeal as water suppliers and health services brace themselves for the possibility of a spring outbreak of a gastrointestinal disease carried in water from the Thirlmere reservoir in Cumbria.

This serves the WN7 postcode area of Leigh.

The disease, cryptosporidium, is contracted from animal faecal matter and causes diarrhoea, headaches, fever, cramping and nausea lasting for 10 to 15 days.

For immuno compromised people, such as those with HIV and Aids, the disease is potentially serious.

The NHS executive reports that each spring several hundred people become infected.

Thirlmere water is supplied through a 100 mile long aqueduct, much of which is underground and covered with grazing land.

Rain water running off the hills can leak into the aqueduct carrying contamination from animal faeces. Crypto outbreaks in the area appear to be associated with the spring lambing season and heavy rainfall.

Prof Ashton said: "The privatised water companies claim to be doing everything they can to tackle the problem, but here in the North West their expensive improvement programme will take up to four years to complete. In the meantime people will continue to become ill."

Responding to Prof Ashton's comments, a spokeman for NWW said: "Water is just one of the means by which cryptosporidium can be transmitted. However waterborne outbreaks, through rare, are of concern to us.

"That is why we have been working closely on this issue with health professionals in the north west, including Professor Ashton, for a number of years.

"The company is well into delivering a £300m investment programme to tackle crypto, and investment on this scale cannot be completed overnight.

"In addition a number of shorter term measures have been taken in agreement with health authorities over the last 12 months to further protect supplies around the region. Information on tap water quakity is already in the public domain and customers can request a report free of charge."