Background In 2012 a UK NICU experienced an outbreak of Ps aeruginosa. 4 months earlier the unit installed sensor taps containing a complex flow straightener with an infra-red sensor on the end of the tap. The same strain of Ps. aeruginosa was found in the flow straightener of 5 sensor taps and clinical samples.¹ Sensor taps were subsequently installed without flow straighteners.

Methods Weekly sampling of tap water was commenced. If a water sample was positive for Ps aeruginosa, the tap and sink were de-commissioned and the tap removed and analysed. Inpatients were screened with weekly skin swabs for Pseudomonas.

Results Over 20 months 4040 samples of tap water were analysed, 2 were positive for Ps aeruginosa. The first episode involved formation of biofilm in threads of a screw on collar at the tap outlet. The second was associated with a visible calcified deposit adjacent to the outlet.

During this period 3 infants were colonised with unique strains of Ps aeruginosa.

Discussion Beginning with the outbreak the tap design was modified after each episode of contamination. The current design has:

1. Absence of a flow straightener

2. A single unit of steel as the tap spout and is removable/ autoclavable. No additional attachments are present.

3. A Teflon coated outlet which minimises droplet adherence under the body of the tap.

4. An infra-red sensor located remotely from the tap.

An environmental source was not identified for any of the colonised infants.

Reference

1. Walker JT, Jhutty AJ, Parks S, et al. Investigation of healthcare- acquired infections associated with Pseudomonaas aeruginosa biofilms in taps in neonatal units in Northern Ireland. Journal of Hospital Infection 2014;86:16–23