Risk factors for nosocomial COVID-19 in a French university hospital.

OBJECTIVES: Prevention strategies implemented by hospitals to reduce nosocomial transmission of SARS-CoV-2 sometimes failed. Our aim was to determine the risk factors for nosocomial COVID-19. PATIENTS AND METHODS: A case-control study was conducted (September 1, 2020-January 31, 2021) with adult patients hospitalized in medical or surgical units. Infants or patients hospitalized in ICU were excluded. Cases were patients with nosocomial COVID-19 (clinical symptoms and RT-PCR + for SARS-CoV-2 or RT-PCR + for SARS-CoV-2 with Ct ≤ 28 more than 5 days after admission); controls were patients without infection (RT-PCR- for SARS-CoV-2 > 5 days after admission). They were matched according to length of stay before diagnosis and period of admission. Analyses were performed with a conditional logistic regression. RESULTS: A total of 281 cases and 441 controls were included. In the bivariate analysis, cases were older (OR per 10 years: 1.22; 95%CI [1.10;1.36]), had more often shared a room (OR: 1.74; 95%CI [1.25;2.43]) or a risk factor for severe COVID-19 (OR: 1.94; 95%CI [1.09;3.45]), were more often hospitalized in medical units [OR: 1.59; 95%CI [1.12;2.25]), had higher exposure to contagious health care workers (HCW; OR per 1person-day: 1.12; 95%CI [1.08;1.17]) and patients (OR per 1 person-day: 1.11; 95%CI [1.08;1.14]) than controls. In an adjusted model, risk factors for nosocomial COVID-19 were exposure to contagious HCW (aOR per 1person-day: 1.08; 95%CI [1.03;1.14]) and to contagious patients (aOR per 1person-day: 1.10; 95%CI [1.07;1.13]). CONCLUSIONS: Exposure to contagious professionals and patients are the main risk factors for nosocomial COVID-19.

Infection Impacts dd-cfDNA in Lung Transplant Recipients

Purpose: Infection is the leading cause of death within 1 year post lung transplant. Graft injury secondary to infection is affected by both source and organism. Donor derived cell-free DNA (dd-cfDNA) is a consistent marker of graft injury, but previously reported dd-cfDNA levels with infections have been inconsistent. We compared dd-cfDNA concentrations across different infection types. Method(s): We reviewed infections in lung transplant recipients (LTR) between 5/2019-6/2021 with paired dd-cfDNA at time of infection. All were confirmed infections (i.e. requiring therapy). Infection source (respiratory vs non-respiratory) and organism were collected. Samples were excluded if there was concurrent ACR, AMR or CLAD at time of dd-cfDNA. The primary endpoint was dd-cfDNA levels across cohorts. Result(s): Fifty paired samples from 20 LTR were identified;31 samples were excluded due to concurrent diagnoses. Infections included viral (n=18, 36%), bacterial (n=18, 36%), and fungal (n=10, 20%). Four cultures (8%) had multiple organisms. Most common within each group were CMV (n=4) and COVID (n=4) for viral, Pseudomonas aeruginosa (n=4) for bacterial, and Aspergillus (n=7) for fungal. Median dd-cfDNA was 1.30% in viral infections, 1.93% in bacterial, and 0.99% in fungal;respiratory infections (n=42) was 1.42% and 0.95% in non-respiratory (n=8). Conclusion(s): There was a statistically significant increase in dd-cfDNA between each infection compared to a normal cohort, but no statistical differences between infection groups. The trend towards significance of respiratory vs non-respiratory indicates that dd-cfDNA may be a useful marker of injury specific to the graft caused by infection. Further investigation with serial samples prior to and following treatment of the infection will be important to better understand this trend. (Figure Presented).

Risk factors of nosocomial COVID-19 at Grenoble Alpes university hospital

Introduction: During the COVID-19 pandemic, hospitals implemented infection prevention strategies to reduce nosocomial transmission. Nevertheless, these strategies sometimes failed and determination of risk factors of transmission is crucial. Objectives: Our main objective was to determine the risk factors of nosocomial Covid-19 at Grenoble Alpes University hospital (CHUGA). Methods: A case-control study was conducted at CHUGA. A retrospective data collection was performed between 01/09/2020 and 31/01/2021. Adults patients hospitalized in medicine or surgery units were included. Infants or patients hospitalized in ICU were excluded. Case patients were patients with a nosocomial Covid-19 (clinical symptoms and positive PCR for SARS-CoV-2 or positive PCR for SARSCoV- 2 ≤ 28CT);control patients were patients without infection (negative PCR for SARS-CoV-2). They were matched by their length of stay and their period of admission. Bivariate and multivariate analysis were performed with a conditional logistic regression by Stata 12.0. Results: A total of 1393 patients with Covid-19 were hospitalized;722 patients were included in the case-control analysis ( ncase = 281;ncontrol = 441). In bivariate analysis, case patients were significantly older (OR:1.25;CI95% [1.12;1.40]), had more often a roommate (OR:1.74;CI95% [1.23;2.43]), more often a co-infection (OR:1.73;CI95% [1.26;2.36]), more often a severity risk factor of Covid-19 (OR:2.06;CI95% [1.14;3.71]) and a higher Charlson comorbidity index (OR:1,09;CI95% [1,01;1,20] than control patients. In an adjusted model that included the admission in the emergency room and the existence of a severity risk factor, the risk factors of nosocomial Covid-19 were: older age (aOR:1.24 per 10 years;CI95% [1.08;4.41]), having a roommate (aOR:1.63;CI95% [1.14;2.33]), and having a co-infection (aOR:1.62;CI95% [1.17;2.26]). Conclusion: Older patients with co-infection hospitalized in a multiple room were more susceptible to nosocomial Covid-19. These preliminary results need to be consolidated taking into account exposition to contagious healthcare workers or contagious patients.

SARS-CoV-2 nosocomial infection acquired in a French university hospital during the 1st wave of the Covid-19 pandemic, a prospective study.

BACKGROUND: In healthcare facilities, nosocomial transmissions of respiratory viruses are a major issue. SARS-CoV-2 is not exempt from nosocomial transmission. Our goals were to describe COVID-19 nosocomial cases during the first pandemic wave among patients in a French university hospital and compliance with hygiene measures. METHODS: We conducted a prospective observational study in Grenoble Alpes University Hospital from 01/03/2020 to 11/05/2020. We included all hospitalised patients with a documented SARS-CoV-2 diagnosis. Nosocomial case was defined by a delay of 5 days between hospitalisation and first symptoms. Hygiene measures were evaluated between 11/05/2020 and 22/05/2020. Lockdown measures were effective in France on 17/03/2020 and ended on 11/05/2020. Systematic wearing of mask was mandatory for all healthcare workers (HCW) and visits were prohibited in our institution from 13/03/2021 and for the duration of the lockdown period. RESULTS: Among 259 patients included, 14 (5.4%) were considered as nosocomial COVID-19. Median time before symptom onset was 25 days (interquartile range: 12-42). Eleven patients (79%) had risk factors for severe COVID-19. Five died (36%) including 4 deaths attributable to COVID-19. Two clusters were identified. The first cluster had 5 cases including 3 nosocomial acquisitions and no tested HCWs were positive. The second cluster had 3 cases including 2 nosocomial cases and 4 HCWs were positive. Surgical mask wearing and hand hygiene compliance were adequate for 95% and 61% of HCWs, respectively. CONCLUSIONS: The number of nosocomial COVID-19 cases in our hospital was low. Compliance regarding mask wearing, hand hygiene and lockdown measures drastically reduced transmission of the virus. Monitoring of nosocomial COVID-19 cases during the first wave enabled us to determine to what extent the hygiene measures taken were effective and patients protected. Trial registration Study ethics approval was obtained retrospectively on 30 September 2020 (CECIC Rhône-Alpes-Auvergne, Clermont-Ferrand, IRB 5891).

Performance of Donor Derived Cell-Free DNA in Routine Clinical Care of Lung Transplant Recipients, a Multi-Center Study

Purpose Prior observational data suggest that donor-derived cell-free DNA (dd-cfDNA) increases in lung transplant acute rejection and infection. The performance of dd-cfDNA in routine clinical care remains undefined. In response to the COVID-19 pandemic, to mitigate the risk of exposing patients to infection, four centers used dd-cfDNA for surveillance instead of surveillance bronchoscopy, providing a unique opportunity to assess the performance of dd-cfDNA in routine clinical care. Methods As part of routine care during the COVID-19 pandemic, four lung transplant centers implemented a home-based surveillance program using plasma dd-cfDNA (Allosure®) in preference to surveillance bronchoscopy. Based on prior data, dd-cfDNA > 1% triggered further work-up including bronchoscopy. dd-cfDNA testing was also performed in response to a decline in forced expiratory volume in 1 second (FEV1), symptoms or treatment follow up. Data was retrospectively analyzed from 4/1/2020 - 9/1/2020 to assess the performance of dd-cfDNA in diagnosing a composite of ACR, AMR and/or infection. Results 169 patients underwent 380 dd-cfDNA measurements over the study period. The mean age was 58.5 years, 54% of patients were male and 82% bilateral lung transplants. 99 (58%) patients were <1 year post-transplant. 327 of 380 dd-cfDNA values were drawn for surveillance reasons. 31 patients had a surveillance level > 1%. Of these, 19/31 (61%) had evidence of ACR, AMR or infection. 115 patients had surveillance levels that remained < 1% over the study period with 109/115 (95%) displaying no clinical evidence of ACR, AMR, infection or decline in FEV1 or symptoms. The remaining 23 patients had levels drawn for clinical indications (non-surveillance). 45 surveillance bronchoscopies were performed with concomitant dd-cfDNA (23 triggered by dd-cfDNA > 1%). For diagnosis of ACR, AMR or infection in these patients, dd-cfDNA > 1% yielded a sensitivity of 84%, specificity of 77%, positive predictive value of 73% and negative predictive value of 87%. Conclusion In this study, dd-cfDNA identified ACR, AMR and/or infection in asymptomatic lung transplant patients that may not have been identified by clinically indicated biopsy alone. Low levels of dd-cfDNA may also be useful in ruling out AMR, ACR and/or infection, supporting its use as a potential non-invasive marker for surveillance monitoring.