Routes of SARS-Cov2 transmission in the intensive care unit: A multicentric prospective study.

BACKGROUND: The risk of SARS-CoV-2 transmission to health care workers in intensive care units (ICU) and the contribution of airborne and fomites to SARS-CoV-2 transmission remain unclear. To assess the rate of air and surface contamination and identify risk factors associated with this contamination in patients admitted to the ICU for acute respiratory failure due to SARS-CoV-2 pneumonia. METHODS: Prospective multicentric non-interventional study conducted from June 2020 to November 2020 in 3 French ICUs. For each enrolled patient, 3 predefined surfaces were swabbed, 2 air samples at 1 m and 3 m from the patient's mouth and face masks of 3 health care workers (HCW) were collected within the first 48 h of SARS-CoV-2 positive PCR in a respiratory sample. Droplet digital PCR and quantitative PCR were performed on different samples, respectively. RESULTS: Among 150 included patients, 5 (3.6%, 95%CI: 1.2% to 8.2%) had positive ddPCR on air samples at 1 m or 3 m. Seventy-one patients (53.3%, CI95%: 44.5% to 62.0%) had at least one surface positive. Face masks worn by HCW were positive in 6 patients (4.4%, CI: 1.6% to 9.4%). The threshold of RT-qPCR of the respiratory sample performed at inclusion (odds ratio, OR= 0.88, 95%CI: 0.83 to 0.93, p < 0.0001) and the presence of diarrhea (OR= 3.28, 95%CI: 1.09 to 9.88, p = 0.037) were significantly associated with the number of contaminated surfaces. CONCLUSION: In this study, including patients admitted to the ICU for acute respiratory failure " contact route " of transmission, i.e. through fomites, seems dominant. While presence of SARS-CoV-2 in the air is rare in this specific population, the presence of diarrhea is associated to surface contamination around Covid patients.

Evaluation of ceftolozane-tazobactam susceptibility on a French nationwide collection of Enterobacterales.

OBJECTIVES: Ceftolozane-tazobactam (C/T) proved its efficacy for the treatment of infections caused by non-carbapenemase producing Pseudomonas aeruginosa and Enterobacterales. Here, we aimed to provide susceptibility data on a large series of Enterobacterales since the revision of EUCAST categorization breakpoints in 2020. METHODS: First, C/T susceptibility was determined on characterized Enterobacterales resistant to third generation cephalosporins (3GCs) (extended spectrum ß-lactamase [ESBL] production or different levels of AmpC overexpression) (n = 213) and carbapenem-resistant Enterobacterales (CRE) (n = 259), including 170 carbapenemase producers (CPE). Then, 1632 consecutive clinical Enterobacterales responsible for infection were prospectively collected in 23 French hospitals. C/T susceptibility was determined by E-test® (biomérieux) and broth microdilution (BMD) (Sensititre™, Thermo Scientific) to perform method comparison. RESULTS: Within the collection isolates, 88% of 3GC resistant strains were susceptible to C/T, with important variation depending on the resistance mechanism: 93% vs. 13% susceptibility for CTX-M and SHV-ESBL producers, respectively. Only 20% of the CRE were susceptible to C/T. Among CPE, 80% of OXA-48-like producers were susceptible to C/T, whereas all metallo-ß-lactamase producers were resistant. The prospective study revealed that 95.6% of clinical isolates were susceptible to C/T. Method comparison performed on these 1632 clinical isolates demonstrated 99% of categorization agreement between MIC to C/T determined by E-test® in comparison with the BMD (reference) and only 74% of essential agreement. CONCLUSION: Overall, C/T showed good activity against wild-type Enterobacterales, AmpC producers, and ESBL-producing Escherichia coli but is less active against ESBL-producing Klebsiella pneumoniae, and CRE. E-test® led to an underestimation of the MICs in comparison to the BMD reference.

Rapid and accurate eXDR screening: use Xpert Carba-R® with FecalSwab®.

The FecalSwab® displays high performances for stool culture, but it was not assessed for carbapenemase-producing Enterobacterales (CPE) screening. We assess the performances of the Xpert Carba-R v2® with the FecalSwab®. Using a collection of 12 CPE strains, the limit of detection was assessed at 158 CFU/swab [interquartile range 93-589]. In 2019, 1540 swabs were included by 4 hospital laboratories, of which 39 (2.5%) yield an invalid result. Among the 1501 valid, 87 (5.8%) were positives by culture and PCR and 25 (1.7%) were discrepant: 7 PCR-negative culture-positive, and 18 PCR-positive culture-negative. Two PCR-positive culture-negative results involved non-Enterobacterales strains: a KPC-producing Acinetobacter baumannii and a KPC-producing Aeromonas spp. The overall percent agreement was 98.3% and the Kappa value was 0.88. FecalSwab® is an accurate sampling device for CPE screening. It allows performing all eXDR screening using a single swab, simplifying the sample collection, and improving the patient comfort. Regarding discrepant, we suggest combining a CPE screening by both culture and Xpert Carba-R v2® methods.

Environmental contamination related to SARS-CoV-2 in ICU patients.

BACKGROUND: The coronavirus disease 2019 (COVID-19) outbreak is a primary global concern, and data are lacking concerning risk of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) environmental contamination. OBJECTIVE: To identify risk factors for SARS-CoV-2 environmental contamination in COVID-19 patients admitted to the intensive care unit (ICU). METHODS: A prospective single centre 1-day study was carried out in an ICU. Four surfaces (the ventilator control screen, the control buttons of the syringe pump, the bed rails and the computer table located >1 m away from the patient) were systematically swabbed at least 8 h after any cleaning process. We analysed clinical, microbiological and radiological data to identify risk factors for SARS-CoV-2 environmental contamination. RESULTS: 40% of ICU patients were found to contaminate their environment. No particular trend emerged regarding the type of surface contaminated. Modality of oxygen support (high-flow nasal cannula oxygenation, invasive mechanical ventilation, standard oxygen mask) was not associated with the risk of environmental contamination. Univariate analysis showed that lymphopenia <0.7×109·L-1 was associated with environmental contamination. CONCLUSION: Despite small sample size, our study generated surprising results. Modality of oxygen support is not associated with risk of environmental contamination. Further studies are needed.

Cohorting for preventing the nosocomial spread of Carbapenemase-Producing Enterobacterales, in non-epidemic settings: is it mandatory?

BACKGROUND: Worldwide dissemination of Carbapenemase-Producing Enterobacterales (CPE) has led to national and international guidance recommending the implementation of cohorting in healthcare settings (HS). However, in view of recent data regarding the spread of Extended-spectrum Beta-lactamase-producing Enterobacterales, we may wonder about the usefulness of this measure in a non-outbreak settings; here, individual contact isolation may be sufficient to control the risk of dissemination. AIM/METHODS: We conducted a narrative review of the literature and discussed the role of cohorting. FINDINGS: CPE are responsible for outbreaks in HS, which are considered the epicentre of spread of resistance strains. CPE are responsible for adverse effects such as increases in hospital stay and costs, less therapeutic options and thus higher risk of clinical failures and mortality. Environment and materials have also been described contaminated with CPE and can be the source of outbreak. Even if guidelines and publications have supported implementation of cohorting, there are no randomized studies demonstrating the mandatory nature of this measure. Most studies are descriptive and cohorting is usually one of several other measures to control outbreaks. Cohorting is not adapted to all HS, which requires human and material resources. Other measures must be strengthened such as compliance of hand hygiene, antibiotic stewardship and surveillance of contact patients. Individual risk factors of acquisition should also be evaluated. CONCLUSION: Local epidemiology and resources must be assessed before implementing cohorting.