The source of a deadly infection at a hospital that has claimed the lives of three babies is unlikely to be identified, an expert said today.
Although staff are trying to establish how the pseudomonas bacteria entered a neonatal room at the Royal Maternity Hospital in Belfast, this could take some time and it may be eradicated before the origin has been found, according to Stephan Heeb, a senior research fellow at the School of Molecular Medical Sciences.
"The normal way to do it is to take swabs of surfaces," he said. "If they find it's heavily colonised in one area, that would be the source of the infection.
"But that takes some days to do and sometimes it's not even worth trying to find it because the urgency is to end the problem, so in practice what is likely to happen is they will disinfect without actually identifying what the source is."
The hospital's hygiene policy would stipulate that everyone washes their hands and equipment is kept clean, he said.
But it would only take one person failing to follow this to cause the kind of outbreak that has proved fatal on the Belfast hospital's ward, he added.
"The hygiene practice is very difficult to maintain and you just need one person not following that," he said. "It can be someone bringing something in on their shoes.
"What can be done is to try and improve the hygiene conditions but these things will always happen and sooner or later a bacterium slips in so it's a bit difficult.
"It's very hard to have zero risk so these things will happen occasionally. It's important it doesn't happen frequently."
The bacteria needs water to survive and proliferate so its source is likely to be an area where fluids are present, he explained.
Pseudomonas is common, he said, and the biggest cause of death among cystic fibrosis patients.
Burns victims and Aids sufferers are also susceptible to it, and babies at at risk because of their underdeveloped immune systems.
Babies in a neonatal unit who were not being breast-fed would not be receiving antibodies from their mother's milk and so would be even more susceptible, Mr Heeb added.
And he warned that while cleaning the affected room was an "excellent first measure", it was important that any equipment brought from one room to another was sterile and anyone handling suspect equipment washed their hands before entering another room.