Legionnaire's disease appears to be a frightening source of claims for insurers, but there are two key defences - abiding by the HSE code of practice and medical causation. Jim Byard reports

Leisure operators and employers in Cumbria and Sandwell in the West Midlands will be going through a stressful time at the moment with the recent outbreaks of legionnaire's disease. Especially as people living within a two-mile radius of the source run the risk of being infected.

Legionnaire's disease is a type of pneumonia caused by the legionnella pneumophila bacterium - of which there are many strains - found predominantly in warm water environments.

The bacteria occur in the natural environment and are found in hot and cold water systems, rivers, showers and Jacuzzis. Upwards of 60% of domestic hot water systems carry the organism, albeit at low concentrations.

The recorded annual incident rate is low, roughly three cases per million people, with the main causes of infections being cooling towers and air conditioning cooling systems.

To the untrained eye this dreadful set of events may appear to have once again thrown up the nightmare scenario of trying to manage the inevitable employers' liability (EL) or public liability (PL) claims resulting from an epidemic of this nature.

However, while legionnella bacteria are difficult to eradicate, with the emphasis firmly on control, insurers and insureds have the opportunity of adopting a more stalwart approach to the claims they may face.

There are two key defences available when defending claims. Complying with the HSE's approved code of practice, which generally ensures a no negligence defence, provides the main cover for insureds, although they can also rely on medical causation.

This can prove to be a more complex defence, as the claimant's medical records need to be checked to identify that the strain of legionnella matches that found at an insured's premises. If not, then it is probable that the bacteria emanated from a different source.

Therefore, the emphasis is firmly on the shoulders of insurers and insureds alike to follow the approved code of practice. This ensures that they have the best defence available in the worst-case scenario. More importantly they must do all they can to reduce the risk of any such outbreak ever occurring in the first place.

Jim Byard is a disease specialist with Weightman Vizards' national workplace litigation team