Can environmental contamination be explained by particular traits associated with patients?

• Published in: The Journal of hospital infection 2020-03, Vol.104 (3), p.293-297
• Main Authors: Pilmis, B., Billard-Pomares, T., Martin, M., Clarempuy, C., Lemezo, C., Saint-Marc, C., Bourlon, N., Seytre, D., Carbonnelle, E., Zahar, J-R.
• Format: Article
• Language: English
• Subjects: Bacteria - isolation & purification; Carrier State - microbiology; Carrier State - transmission; Cohort Studies; Cross Infection - microbiology; Cross Infection - prevention & control; Cross Infection - transmission; Disease Reservoirs; Environmental contamination; Environmental Microbiology; Humans; Life Sciences; Patients' Rooms; Prospective Studies; Risk factors
• ISSN: 0195-6701; 1532-2939
• DOI: 10.1016/j.jhin.2019.12.011

Little is known about patient risk factors associated with environmental contamination. To evaluate the rate of environmental contamination and to investigate individual risk factors. 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. 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). 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.