Water tank manufacturers are being asked to redesign systems after potentially-lethal Pseudomonas bacteria was found in pipework at two hospitals in Fife.
All Scottish health boards have been alerted by Health Protection Scotland (HPS) after its estates department discovered the penicillin-resistant bug at the new Victoria Hospital in recent months and at St Andrew's Community Hospital in 2010.
While no one has become ill as a result of the bug, it has prompted concerns over infection control practices in healthcare settings.
And HPS has informed water tank manufacturers because the contamination in both cases was connected to the design used by at least three suppliers.
Health boards have also been told to inspect suspect water tanks with the same sort of structure and replace them with a new frame less susceptible to the growth of bacteria.
A spokesman for NHS Fife said: "We can confirm that following routine testing procedures higher-than-anticipated levels of bacteria were observed within a tank at Victoria Hospital, Kirkcaldy, this year. The type of bacteria found are commonly present within water supplies.
"Immediate action was taken in line with recognised procedures to minimise any risk and ensure the continued safe supply of water, with minimum disruption to clinical services and hospital users."
The spokesman confirmed no harm was caused to any patients, staff or visitors, and added: "Similar routine testing in 2010 also observed increased levels of bacteria at St Andrews Community Hospital. As a result of these two instances and the similarity in the tanks' construction, NHS Fife alerted National Services Scotland."
In 2011 and 2012 Pseudomonas was found to have behind the deaths of four babies at neonatal units in Ireland. A subsequent investigation revealed traces of the bug in every neonatal unit in the country.
Pseudomonas is a genus of gamma proteobacteria. It is widely found in soil and stagnant water and can infect humans and plants. The bugs do not usually cause illness in healthy people, but are ‘opportunistic’, causing serious infection when a person’s normal defences are weakened. This means they can pose a major threat to the most-vulnerable hospital patients, most commonly, as in the recent cases, intensive care patients and those with compromised immunity, including babies in neonatal units, burns patients and those with cancer.
Pseudomonas bacteria thrive in water systems, particularly large-scale ones such as those found in big industrial buildings, leisure centres and hospitals. Older hospital buildings are particularly at risk as, when the water system is adapted for a change of use or to feed new buildings, deadlegs are created. These are pipes which are effectively cut off, leaving a small dead end where water can become trapped. This stagnant water is a known breeding ground for Pseudomonas bacteria.