ABSTRACT
Introduction: Diagnosis of ventilator-associated pneumonia (VAP) in COVID-19 patients remains challenging. Also, the lack of gold standard for microbiological sampling undermines clinical judgement and management. We studied incidences of microbiologically-confirmed VAP comparing endotracheal aspirate (ETA) and bronchoalveolar lavage (BAL) in COVID-19 patients. Etiological agreement between ETA and BAL was then assessed. Method(s): Single-center prospective cohort study (NCT04766983). Patients were enrolled within 48 h from intubation;surveillance ETA ( ETASURV) was performed twice weekly. ETA ( ETACX) and BAL ( BALCX) samples were collected upon VAP suspicion (Johanson's criteria). CDC definitions were used for microbiological confirmation. ETA-BAL agreement (interrater reliability and Cohen's kappa) and clinical/microbiological data were assessed for the first episodes of suspected VAP per patients. Result(s): Ninety intensive care (ICU) patients enrolled from 01/2021 to 05 06/2022, of which 26 females (28.9%);median age was 60 [52-66] years. In-ICU mortality was 30/90 (33.3%), median length of stay in survivors 19 (10-32) days. Fifty-three patients (58.9%) had >= 1 episode of suspected VAP after 6 [5;10] days from ICU admission. ETASURV were available in 52 cases, 2 [1;3] days before VAP suspect, and tested positive in 28 (53.8%). ETACX and BALCX resulted positive in 35 (66.0%) and 29 (54.7%) of episodes. Main microbiological results are displayed in Fig. 1, panel A. Etiological agreement between techniques is shown in Fig. 1, panel B. Incidence rate of VAP suspicions per 1000 ventilator-days was 60.2 (95% CI 43.9-76.4), while incidence rates of microbiologically-confirmed VAP were 27.4 (18.3-36.5) with ETACXand 18.9 (95% CI 12.0-25.8) with BALCX, respectively. Conclusion(s): We observed different incidence of VAP in COVID-19 ICU patients depending on sampling method. Etiological agreement between techniques yielded limited interrater reliability. The potential clinical impact needs further studies.
ABSTRACT
Introduction: Registration studies have shown high efficacy of BNT162b2 mRNA COVID-19 vaccine. We evaluated vaccine effectiveness (VE) of BNT162b2 mRNA COVID-19 vaccine in a cohort of healthcare workers (HCWs) of a large hospital in Milan, Lombardy, Italy. Material and Methods: Follow-up started on 27 December 2020 (beginning of the vaccination campaign). HCWs without history of SARS-CoV-2 infection before the start date and with at least a nasopharyngeal test afterwards were included. Vaccination was treated as a time-dependent variable. For selected periods after vaccination we calculated incidence rate ratios (IRR) and 95% confidence intervals (CI) of infection with a Poisson regression model adjusted for gender, age, occupation, and 30-day periods, and then VE as (1 – IRR)x100 using unvaccinated person-time as reference. Databases were closed on 27 September 2021. The study was approved by the hospital’s ethics committee (Milano Area 2, Prot. No. 828_2021bis). Results and Conclusions: We included 3,809 HCWs, 131 still unvaccinated and 3,678 vaccinated (3,576 with two doses). We identified 134 infections (62% symptomatic). Adjusted VE was 77% (CI: 43-91) from day 14 after the first vaccine dose and 87% (CI: 79-92) at least 7 days after the second dose. After full vaccination schedule VE was 89% (CI: 82-94) for symptomatic and 77% (CI: 45-90) for asymptomatic infections. In conclusion, we found high effectiveness of BNT162b2 vaccine in reducing incidence of both symptomatic and asymptomatic infections. The follow-up is continuing to assess long-term effectiveness, also considering emerging SARS-CoV-2 variants.
ABSTRACT
OBJECTIVES: The management of healthcare workers (HCWs) exposed to confirmed cases of coronavirus disease 2019 (COVID-19) is still a matter of debate. We aimed to assess in this group the attack rate of asymptomatic carriers and the symptoms most frequently associated with infection. METHODS: Occupational and clinical characteristics of HCWs who underwent nasopharyngeal swab testing for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a university hospital from 24 February 2020 to 31 March 2020 were collected. For those who tested positive and for those who tested positive but who were asymptomatic, we checked the laboratory and clinical data as of 22 May to calculate the time necessary for HCWs to then test negative and to verify whether symptoms developed thereafter. Frequencies of positive tests were compared according to selected variables using multivariable logistic regression models. RESULTS: There were 139 positive tests (8.8%) among 1573 HCWs (95% confidence interval, 7.5-10.3), with a marked difference between symptomatic (122/503, 24.2%) and asymptomatic (17/1070, 1.6%) workers (p < 0.001). Physicians were the group with the highest frequency of positive tests (61/582, 10.5%), whereas clerical workers and technicians had the lowest frequency (5/137, 3.6%). The likelihood of testing positive for COVID-19 increased with the number of reported symptoms; the strongest predictors of test positivity were taste and smell alterations (odds ratio = 76.9) and fever (odds ratio = 9.12). The median time from first positive test to a negative test was 27 days (95% confidence interval, 24-30). CONCLUSIONS: HCWs can be infected with SARS-CoV-2 without displaying any symptoms. Among symptomatic HCWs, the key symptoms to guide diagnosis are taste and smell alterations and fever. A median of almost 4 weeks is necessary before nasopharyngeal swab test results are negative.