Outbreak of pseudomonas aeruginosa in a neonatal intensive care unit: Are point-of-use filters useful?

Abstract

Pseudomonas aeruginosa, in intensive care units (ICUs), causes infections with high morbidity and mortality rates. Tap water outlets are often contaminated with P.aeruginosa and may represent a source of endemic infections in ICUs. The aim of this study was to explore the role of point-of-use (POU) filters in neonatal intensive care unit (NICU) in reducing P.aeruginosa colonizations/infections. Routine surveillance cultures, environmental cultures and samples from the hands of healthcare personnel, were taken and cultivated. P.aeruginosa isolates were identified according to standard procedures. For epidemiological purposes, antimicrobial susceptibility testing and pulsefield gel electrophoresis were performed. Data regarding use of antibiotics, disinfectants, antiseptics, gloves and gowns from 2006 to 2012 were investigated. In March 2008, in the NICU of the Clinical Hospital Centre Zagreb (CHC Zagreb), we observed an increase in the total number of pseudomonas infections compared to the previous months. This higher number remained the same until October, despite rigorous infection control measures. Pseudomonas isolates were found in tap water, but not on the hands of healthcare workers. In that moment POU filters were introduced. The number of P.aeruginosa isolates in surveillance cultures dropped significantly. The number of positive cultures of P.aeruginosa in two consecutive periods (before and after installation of POU filters) showed a statistically significant difference. After the implementation of all infection control measures, we managed to stop the spread of pseudomonas colonization/ infection. POU filters contributed only as one of these measures, resulting in a reduction of chronically endemic P.aeruginosa infection/colonisation in the NICU.