COMMUNICATIONS

CDHB Reviews Use of Filtered Water

Canterbury Medical Officer of Health, Dr Mel Brieseman is warning businesses and the public that water filters in equipment such as office-style water coolers need to be changed regularly to prevent the build up of a variety of bacteria including legionella. This is in addition to standard advice to use masks and gloves when handling potting mix to prevent legionellosis.

Small amounts of legionella occur naturally in all untreated water supplies such as that in Christchurch but can multiply to potentially harmful levels in the right conditions. The risk of ill health from drinking water containing significant amounts of legionella is however thought to be low compared to inhaling it as mist or steam.

Dr Brieseman’s warning comes after testing of 14 office-style water coolers at Christchurch Hospital revealed that one had a significant level of legionella in its filter. There is no evidence that this water cooler is linked to any Christchurch Hospital visitors or patients becoming unwell. The cooler, which had a filter with some months before expiry, was promptly removed from the hospital after results of the testing were confirmed.

Water filters in most drinking water coolers are designed to remove taste and odour and do not offer any protection against micro-organisms. If water filters are not changed regularly, bacteria can build to high levels in them. The drinking - water filters from CDHB’s main supplier were found to be healthy but the Board is now considering whether it needs to remove all filters from its water coolers to protect patients that may be more vulnerable to infection than most of the population. Anyone who has questions about filters in their own equipment should discuss it with their supplier.

“Office-style water coolers and drinking-water filters are not usually checked for legionella because the disease is generally contracted via aerosol spray,” Dr Brieseman said, “We believe this is the first case of significant levels of legionella being detected in a drinking water cooler anywhere in the world, so we will be publishing the findings as a scientific curiosity.”

Water supplies in all CDHB hospitals are regularly monitored to ensure that legionella is not present at harmful levels and preventative procedures are used to ensure the water is healthy.

ENDS