Pseudomonas aeruginosa in hospital water systems: biofilms, guidelines, and practicalities.

Pseudomonas aeruginosa is one of many micro-organisms that can act as an opportunistic pathogen and colonize and infect vulnerable patients. Hospital water is a recognized source P. aeruginosa. Several outbreaks, including the incidents involving babies in Northern Ireland in 2011/12, have been attributed to contaminated water systems. As a direct result of the deaths of four neonates in Northern Ireland, guidance documents--addendums to Health Technical Memorandum 01-04 (Department of Health, England)--were produced to advise National Health Service managers on how to deal with the presence of P. aeruginosa in augmented care units. The guidance was based on current expert opinion and limited scientific evidence. Public Health England has established a reproducible and controllable water distribution test rig in a laboratory setting to further understand the contamination of water systems by P. aeruginosa and to identify vulnerable sites for microbial colonization. It is anticipated that these studies will add to the evidence base and enable the guidance documents to be updated in due course.