A Prolonged Outbreak ofPseudomonas Aeruginosain a Neonatal Intensive Care Unit Did Staff Fingernails Play a Role in Disease Transmission?

Abstract

AbstractObjectives:To describe an outbreak ofPseudomonas aeruginosabloodstream infection (BSD and endotracheal tube (ETT) colonization in a neonatal intensive care unit (NICU), determine risk factors for infection, and make preventive recommendations.Design:A 15-month cohort study followed by a case-control study with an environmental survey and molecular typing of available isolates using pulsed-field gel electrophoresis.Setting and Patients:Neonates in the NICU of a university-affiliated children's hospital.Interventions:Improved hand washing and restriction of use of long or artificial fingernails.Results:Of 439 neonates admitted during the study period, 46 (10.5%) acquiredP aeruginosa; 16 (35%) of those died. Fifteen (75%) of 20 patients for whom isolates were genotyped had genotype A and 3 (15%) had genotype B. Of 104 healthcare workers (HCWs) from whom hand cultures were obtained,P aeruginosawas isolated from three nurses. Cultures from nurses A-1 and A-2 grew genotype A and cultures from nurse B grew genotype B. Nurse A-1 had long natural fingernails, nurse B had long artificial fingernails, and nurse A-2 had short natural fingernails. On multivariate logistic regression analysis, exposure to nurse A-l and exposure to nurse B were each independently associated with acquiring a BSI or ETT colonization withP aeruginosa, but other variables, including exposure to nurse A-2, were not.Conclusion:Epidemiological evidence demonstrated an association between acquiringP aeruginosaand exposure to two nurses. Genetic and environmental evidence supported that association and suggested, but did not prove, a possible role for long or artificial fingernails in the colonization of HCWs' hands withP aeruginosa. Requiring short natural fingernails in NICUs is a reasonable policy that might reduce the incidence of hospital-acquired infections.