The Health Protection Agency is calling for more research to see if Legionnaire's Disease is connected to not using screenwash in your windscreen water reservoir.

An HPA spokeswoman said: "This preliminary HPA study suggests a strong association between a lack of screen wash in wiper fluid and the incidence of Legionnaires' disease. Further studies are now needed to determine whether the use of screen wash in wiper fluid could play a role in preventing this disease."

The disease is not common in England and Wales and is usually traced to water aerosol systems like air-con, cooling towers or showers.

The study was undertaken after an especially high number of cases in summer 2006.

It found there was a much higher incidence among professional drivers, probably due to driving through other outside sources of the disease.

Researchers found an even stronger association between non-professional drivers without screenwash in their reservoirs and the disease. This warm, stagnant water can provide the perfect environment for Legionella bacteria.

When the water is sprayed over the windscreen it is likely that some aerosol would be sucked into the passenger compartment - or through an open window.

A separate investigation by the Environmental Protection Agency found that one in five cars tested had Legionella in their windscreen wiper fluid. None of the cars which had screenwash added tested positive for the bacteria.

This gave them a possible figure of 20 per cent of community-acquired cases of Legionnaire's Disease could be avoided by using screenwash.

Legionnaire's Disease is an uncommon form of pneumonia. It was named after an outbreak at an American Legion convention in 1976 which killed 29 veterans. ®