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Can environmental contamination be explained by particular traits associated with patients?
B Pilmis1, T Billard-Pomares2, M Martin3
1Equipe Mobile de Microbiologie Clinique, Groupe Hospitalier Paris Saint Joseph, Paris, France; EA4043 Unité Bactéries Pathogènes et Santé, Université Paris-Sud Paris-Saclay, Chatenay-Malabry, France.
Background:
Little is known about patient risk factors associated with environmental contamination.
Aim:
To evaluate the rate of environmental contamination and to investigate individual risk factors.
Methods:
A prospective cohort study was conducted. Each day, five rooms occupied by patients were selected. Five critical surfaces were systematically swabbed twice a day before and after cleaning. Clinical characteristics of all patients were collected. Logisitic regression was performed to evaluate the association between environmental contamination and patients' characteristics.
Findings:
A total of 107 consecutive patients were included and 1052 environmental samples were performed. Nineteen (18%) patients were known previously colonized/infected with a multidrug-resistant organism (MDRO). Respectively, 723 (69%) and 112 (11%) samples grew with ≥1 and >2.5 cfu/cm2 bacteria, resulting in 62 (58%) contaminated rooms. Considering positive samples with at least one pathogenic bacterium, 16 (15%) rooms were contaminated. By univariate and multivariate analysis, no variables analysed were associated with the environmental contamination. Considering contaminated rooms with >2.5 cfu/cm2, three factors were protective for environmental contamination: known MDRO carriers/infected patients (odds ratio: 0.25; 95% confidence interval: 0.09-0.72; P = 0.01), patients with urinary catheter (0.19; 0.04-0.89; P = 0.03) and hospitalization in single room (0.3; 0.15-0.6; P < 0.001).
Conclusion:
This study was conducted in a non-outbreak situation and showed a low rate of environmental contamination with pathogenic bacteria. Only 11% of environmental samples grew with >2.5 cfu/cm2, and they were related to non-pathogenic bacteria. No risk factors associated with environmental contamination were identified.
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