Colonization pressure as a risk factor for colonization by multiresistant Acinetobacter spp and carbapenem-resistant Pseudomonas aeruginosa in an intensive care unit

• Published in: Clinics (São Paulo, Brazil) Vol. 68; no. 8; pp. 1128 - 1133
• Main Authors: DalBen, Mirian Freitas, Basso, Mariusa, Garcia, Cilmara Polido, Figueiredo Costa, Silvia, Maria Toscano, Cristiana, Robert Jarvis, William, Lobo, Renata Desordi, Oliveira, Maura Salaroli, Levin, Anna Sara
• Format: Journal Article
• Language: English
• Published: Brazil Elsevier España, S.L.U 01-01-2013; Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo; Faculdade de Medicina / USP; Elsevier España
• Subjects: Acinetobacter - drug effects; Acinetobacter Infections - epidemiology; Acinetobacter Infections - microbiology; Acinetobacter Infections - prevention & control; Acinetobacter spp; Adolescent; Adult; Aged; Aged, 80 and over; APACHE; Bacterial Load; beta-Lactam Resistance; Brazil - epidemiology; Carbapenem Resistance; Carbapenems; Child; Child, Preschool; Clinical Science; Colonization Pressure; Cross Infection - epidemiology; Cross Infection - microbiology; Cross Infection - prevention & control; Drug Resistance, Multiple, Bacterial; Female; Hand Hygiene; Hospitalization; Humans; Intensive Care Units; Male; MEDICINE, GENERAL & INTERNAL; Middle Aged; Pseudomonas Aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas Infections - epidemiology; Pseudomonas Infections - microbiology; Pseudomonas Infections - prevention & control; Risk Factors; Time Factors; Young Adult; Brazil; Carbapenem Resistance; Pseudomonas Aeruginosa; Acinetobacter spp; Colonization Pressure; Hand Hygiene
• ISSN: 1807-5932; 1980-5322; 1980-5322
• DOI: 10.6061/clinics/2013(08)11

To determine factors associated with colonization by carbapenem-resistant Pseudomonas aeruginosa and multiresistant Acinetobacter spp.
Surveillance cultures were collected from patients admitted to the intensive care unit at admission, on the third day after admission and weekly until discharge. The outcome was colonization by these pathogens. Two interventions were implemented: education and the introduction of alcohol rubs. Compliance with hand hygiene, colonization pressure, colonization at admission and risk factors for colonization were evaluated.
The probability of becoming colonized increased during the study. The incidence density of colonization by carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. and colonization pressure were different between periods, increasing gradually throughout the study. The increase in colonization pressure was due to patients already colonized at admission. The APACHE II score, colonization pressure in the week before the outcome and male gender were independent risk factors for colonization. Every 1% increase in colonization pressure led to a 2% increase in the risk of being colonized.
Colonization pressure is a risk factor for carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. colonization. When this pressure reaches critical levels, efforts primarily aimed at hand hygiene may not be sufficient to prevent transmission.