Water bug claims more victims

French-owned company waiting for test results after red alert

A company whose water supply has been contaminated with a microscopic parasite yesterday warned there could be further cases of severe stomach sickness, after another five people fell victim to the infection.

And the French-owned Three Valleys Water admitted that they still cannot give customers the all-clear because they have not received the results of tests carried out more than 72 hours ago.

On Monday the company issued an emergency boiling water notice to nearly one million customers as a "precautionary measure" after public health officials issued a red alert when 32 people contracted a severe stomach bug.

The water-borne micro- organism, cryptosporidium, causes severe diarrhoea lasting up to three weeks and is potentially fatal for children and people who have deficient immune systems.

The company's communications manager, Frank Fitzpatrick, said: "We should have had the results within 24 hours and we are waiting for them at the moment. Some of the tests carried out on Friday were positive, but at this stage we haven't had a complete list of results from Saturday."

Five bore holes and three reservoirs, supplying water to homes in West Hertfordshire and north-west London, have been closed down following the scare.

Dr Barry Tennison, director of public health for West Hertfordshire Health Authority, said more cases were expected in the next few days.

"There is between a seven and 10-day incubation period, so I expect we will be seeing new cases later this week.

"There are usually 4,000 cases each year, but we are seeing significantly more than normal at the moment. Luckily, no one is seriously ill at this stage.

"It will be some time before we are going to be able to give people the all-clear and lift the boil notice."

Cryptosporidium belongs to a group of protozoa occurring in the dung of farm animals, which can be washed from agricultural land into nearby rivers.

It is normally spread through contaminated water or contact with an infected person, but unpasteurised milk and offal also carry risks.

Independent inspectors from the Drinking Water Inspectorate yesterday met Three Valley officials for the first time to carry out a detailed investigation into the outbreak.

A spokeswoman for the Department of the Environment said: "If we find that the companies have been negligent in their testing of water supplies, then we reserve the right to prosecute them."

The first confirmed cases of cryptosporidium in tap water in the UK emerged in 1989 when 500 people were affected in Oxfordshire and North Humberside.

Thames Water later offered pounds 62,000 compensation to the 62 people who fell ill.

In 1995 an outbreak in south Devon left 575 people sick. South West Water are now facing prosecution charged with supplying water unfit for human consumption.

Philip Lightowlers, of the Environmental Data Service, said: "We may be seeing a rise in the number of outbreaks. There is a possibility that increased drought causes ground water supplies to change their filtration process.

"Rather than the rocks acting as a natural filtration, weaning out cryptosporidium, arched cracks may be forming allowing the organism to pass through the enlarged gaps."

t A Derbyshire company claims it has the technology to stop cryptosporidium ever occurring.

Memcor Ltd, which specialises in water treatment, says it can prevent similar water-borne outbreaks occurring.

The company uses Continuous Microfiltration, a membrane technology which uses pores to stop contaminants from entering the water supply.

Andy Walton, spokesman for Memcor, said: "We use a straw-like fibre which acts as a filter with pores which are 0.2 microns in size.

"Something like cryptosporidium is five microns so it naturally cannot pass through the filter."

Britain's water companies would have to pay around pounds 8m if they decided to invest in the latest technology to treat the country's supplies.