Research by the University of New South Wales has warned of the potential danger of Legionella breeding in garden hoses – something that has been seen in other countries including Brazil and the Netherlands. According to the study, legionella multiplies inside garden hoses lying in the summer heat as host cells, free-living amoebae, increase virulence rapidly. In the UK, with our lower temperatures, the risk of garden hoses harbouring legionella must be fairly small (though still a possibility in the hotter months). However, there are still many opportunities for this dangerous bacteria to flourish in other areas where the conditions are right.

Where do you usually find legionella?

Legionella is common in lots of places from ponds to canals given that bacteria needs water for the pathogen to grow. However,the conditions surrounding these areas mean that people rarely contract the disease from these sources. Exposure is more common in man-made systems where the temperature ranges between 20-45 ◦C: the perfect level for the bacteria to grow.

High risk locations include spa pools, evaporative condensers, water tanks, showers and cooling towers. But there are many more areas that are at risk and that is why it is important to be proactive in assessing and managing this risk. In fact, legionella outbreaks in public spas are comparable to the potential legionella concentration within the aerosols of a hose.

The repercussions of a Legionnaire’s outbreak are serious – illness or loss of life, impact on business reputation and criminal conviction and fines to name a few.

How do you prevent a legionella outbreak?

With the stakes so high, taking risks is not an option – get a qualified Legionella risk assessment and invest in a programme of testing, treatment and preventative maintenance.