Randomized study of antiseptic application technique in healthy volunteers before vascular access insertion (TApAS trial).

BACKGROUND: In France about 32% of hospitalized patients have a vascular access placement. However, a common complication associated with these is catheter-related bloodstream infection (CRBI) due to the introduction of microorganisms from the skin during catheter insertion. There is no consensus on the best way to clean the skin prior to catheter insertion, which could be a key element of CRBI prevention. The two techniques most commonly used to apply antiseptic to the skin are the concentric circle and back-and-forth techniques, but these have not been compared in clinical trials. Hence, this study conducted this comparison. METHODS: This single-center, non-comparative, randomized, matched pilot study investigated the levels of cutaneous microorganisms before and after antiseptic application using both techniques in a population of healthy French volunteers. The two application methods were used on each participant's arms at the elbow fold, with randomization for the application side (right or left). Quantification of cutaneous microorganisms was performed in a blinded manner with regard to the technique used. FINDINGS: From April 8 to July 17, 2019, 132 healthy volunteers participated in the study. For the whole study population, the mean initial colonization level was 2.68 log10 colony forming units (CFU)/mL (SD 0.82) before the back-and-forth technique, and 2.66 log10 CFU/mL (SD 0.85) before the concentric circle technique. The mean differences in number of microorganisms between the initial sample and the final sample were 2.45 log10 CFU/mL (95% CI: 2.29 to 2.61) for the back-and-forth technique and 2.43 log10 CFU/mL (95% CI: 2.27 to 2.59) for the concentric circle technique. The mean difference in reduction in microorganisms between the back-and-forth technique and the concentric circle technique was 0.02 log10 CFU/mL (95% CI: -0.11 to 0.15). INTERPRETATION: There was no clinically difference in reduction of microorganisms between the concentric circle and back-and-forth techniques at the bend of the healthy volunteer's elbow, after the 30 s of drying of the antiseptic. These findings have a significant impact on time required to achieve antiseptic application before catheter insertion because there is yet no argument to justify application for 30 s, because a single concentric circle pass was much faster with similar results. Future studies should investigate the impact of skin application technique on the prevention of infectious risk associated with catheter insertion on admission to health care facilities (conventional, outpatient, or emergency) and throughout the period of stay in a health care facility.

Pseudomonas aeruginosa acquisition on an intensive care unit: relationship between antibiotic selective pressure and patients' environment.

INTRODUCTION: The purpose of this study was to investigate the relationship among Pseudomonas aeruginosa acquisition on the intensive care unit (ICU), environmental contamination and antibiotic selective pressure against P. aeruginosa. METHODS: An open, prospective cohort study was carried out in a 16-bed medical ICU where P. aeruginosa was endemic. Over a six-month period, all patients without P. aeruginosa on admission and with a length of stay >72 h were included. Throat, nasal, rectal, sputum and urine samples were taken on admission and at weekly intervals and screened for P. aeruginosa. All antibiotic treatments were recorded daily. Environmental analysis included weekly tap water specimen culture and the presence of other patients colonized with P. aeruginosa. RESULTS: A total of 126 patients were included, comprising 1,345 patient-days. Antibiotics were given to 106 patients (antibiotic selective pressure for P. aeruginosa in 39). P. aeruginosa was acquired by 20 patients (16%) and was isolated from 164/536 environmental samples (31%). Two conditions were independently associated with P. aeruginosa acquisition by multivariate analysis: (i) patients receiving ≥3 days of antibiotic selective pressure together with at least one colonized patient on the same ward on the previous day (odds ratio (OR) = 10.3 ((% confidence interval (CI): 1.8 to 57.4); P = 0.01); and (ii) presence of an invasive device (OR = 7.7 (95% CI: 2.3 to 25.7); P = 0.001). CONCLUSIONS: Specific interaction between both patient colonization pressure and selective antibiotic pressure is the most relevant factor for P. aeruginosa acquisition on an ICU. This suggests that combined efforts are needed against both factors to decrease colonization with P. aeruginosa.

Influence of amoebae and physical and chemical characteristics of water on presence and proliferation of Legionella species in hospital water systems.

The reservoir for hospital-acquired Legionnaires' disease has been shown to be the potable water distribution system. The objectives of the present study were as follows: (1) to examine the possible relationship between physical-chemical characteristics of water such as temperature, pH, hardness, conductivity, and residual chlorine and the presence of amoebae as growth-promoting factors for Legionella species and (2) to determine eradication measures for water distribution systems to seek ways of reducing the risk of legionellosis. Ten hospitals in southwest France took part in this study. Water samples were collected from 106 hot water faucets, showers, hot water tanks, and cooling towers. Two analyses were performed to analyze the association between water characteristics and (1) the presence of Legionella species and (2) the proliferation of Legionella species. Of the 106 water samples examined, 67 (63.2%) were positive for Legionella species. Amoebae were detected in 73 of 106 (68.9%) samples and in 56 of 67 (86.6%) Legionella species-positive samples (P < 10(-6)). In these positive samples, conductivity was lower than 500 microOmega(-1).cm(-1) in 58.2% (P = .026), temperature was below 50 degrees C in 80.6% (P = .004), and hardness was significantly higher (P = 002) than in Legionella species-negative samples. Neither Legionella species nor amoebae were isolated from any sampling point in which the water temperature was above 58.8 degrees C. Multivariate analysis shows that high hardness and presence of amoebae were strongly correlated statistically with the presence of Legionella when showers, tanks, pH, and temperature promoted their proliferation. This study shows the importance of water quality evaluation in assessing environmental risk factors and in selecting the most appropriate prevention and control measures in hospital water systems.