The Effect of Test Timing on the Probability of Positive SARS-CoV-2 Swab Test Results: Mixed Model Approach.

BACKGROUND: During the COVID-19 pandemic, swab tests proved to be effective in containing the infection and served as a means for early diagnosis and contact tracing. However, little evidence exists regarding the correct timing for the execution of the swab test, especially for asymptomatic individuals and health care workers. OBJECTIVE: The objective of this study was to analyze changes in the positive findings over time in individual SARS-CoV-2 swab tests during a health surveillance program. METHODS: The study was conducted with 2071 health care workers at the University Hospital of Verona, with a known date of close contact with a patient with COVID-19, between February 29 and April 17, 2020. The health care workers underwent a health surveillance program with repeated swab tests to track their virological status. A generalized additive mixed model was used to investigate how the probability of a positive test result changes over time since the last known date of close contact, in an overall sample of individuals who tested positive for COVID-19 and in a subset of individuals with an initial negative swab test finding before being proven positive, to assess different surveillance time intervals. RESULTS: Among the 2071 health care workers in this study, 191 (9.2%) tested positive for COVID-19, and 103 (54%) were asymptomatic with no differences based on sex or age. Among 49 (25.7%) cases, the initial swab test yielded negative findings after close contact with a patient with COVID-19. Sex, age, symptoms, and the time of sampling were not different between individuals with an initial negative swab test finding and those who initially tested positive after close contact. In the overall sample, the estimated probability of testing positive was 0.74 on day 1 after close contact, which increased to 0.77 between days 5 and 8. In the 3 different scenarios for scheduled repeated testing intervals (3, 5, and 7 days) in the subgroup of individuals with an initially negative swab test finding, the probability peaked on the sixth, ninth and tenth, and 13th and 14th days, respectively. CONCLUSIONS: Swab tests can initially yield false-negative outcomes. The probability of testing positive increases from day 1, peaking between days 5 and 8 after close contact with a patient with COVID-19. Early testing, especially in this final time window, is recommended together with a health surveillance program scheduled in close intervals.

Comparing swab- and different symptoms-based strategies to ascertain COVID-19 recovery in healthcare workers: a cost-effectiveness analysis.

OBJECTIVE: Given the human and economic cost of the COVID-19 pandemic, protecting healthcare workers (HCW) and ensuring continuity of care is critical. The aim of this study is to evaluate the cost-effectiveness of different strategies to ascertain COVID-19 recovery in HCWs. METHODS: Data were collected from the hospital health surveillance program on HCWs at the University Hospital of Verona between 29/02/2020 and 14/04/2021. The diagnosis of SARS-CoV-2 infection and the assessment of the recovery were made through RT-PCR on oro-nasopharyngeal swab-sample. Recovery time and probability were estimated through Kaplan-Meier estimate. For each recovery assessment strategy costs (laboratory diagnostics and human resources), expressed in local currency (euro-€), and working days saved (WDS-effectiveness) were estimated. A decision-tree was created where each knot was a time point scheduled by the different recovery assessment strategies. A Monte Carlo simulation method was used, and probabilistic sensitivity analysis assessed the effect of input uncertainty. RESULTS: In the study period 916 (9.9%) HCWs tested positive. Recovery time through symptom-based strategy (21 days 0.95 CI 16-24) was significantly lower compared to swab-based one (25 days 0.95 CI 23-28, p < 0.001). The swab-based strategy was dominated by all symptoms-based ones. Symptoms-based with a swab on days 14 and 17 had an ICER of 2 €/WDS and 27 €/WDS compared to the one scheduled on days 10 and 17 and with only one swab on the 17th day. CONCLUSIONS: Scheduling swabs on days 14 and 17 in a symptom-based strategy was the most cost-effective, saving 7.5 more working days than the standard one with swabs on days 10 and 17.

COVID-19: opinions and behavior of Italian general population during the first epidemic phase.

BACKGROUND AND AIM: On January 9, 2020, the World Health Organization (WHO) declared that Chinese health authorities had identified a new coronavirus strain never before isolated in humans, the 2019-nCoV later redefined SARS-CoV-2, that still today represent a public health problem. The present survey started on 10 February 2020 with the aim of a) assessing the risk perception in healthcare workers and young students, following the evolution of attitudes, perception and knowledge over time, b) provide useful information to the general population during survey. RESULTS: A study sample consisting of 4116 Italian individuals of both sexes was enrolled. High levels of risk perception, low perception of self-efficacy and low levels of knowledge scores (24.55 ± 5.76 SD) were obtained indicating the need for continuous population monitoring as well as further communication strategies carried out at institution levels. CONCLUSION: The results of the present study could help public health authorities in carrying out informative campaigns for general population and could be an important tool in evaluating public knowledge and misperceptions during the management of the COVID-19. (www.actabiomedica.it).

Improving Risk Management by Learning from Adverse Events: Report on One Year of COVID-19 Vaccination Campaign in Verona (Northeastern Italy).

BACKGROUND: The COVID-19 mass vaccination campaign posed new challenges not only from a healthcare perspective, but also in terms of distribution, logistics, and organization. Managing clinical risk in off-site vaccination centers during a pandemic provided a new opportunity for the training and acquisition of competencies through continuous learning from adverse events. The aim of this report, based on a review of activity, was to identify the most recurrent and high-risk failures of the vaccination process in a mass vaccination center. METHODS: Adverse events and near misses reported during the first 11 months of activity (February 2021-January 2022) in the mass vaccination center of Verona (Italy) were evaluated. RESULTS: From 15 February 2021 to 17 January 2022 the center administered about 460,000 doses to the population and nine adverse events and one near miss were reported. Most of the events were errors in vaccine administration, either in principle, dosage, or timing with respect to the indicated schedule. All events had minor outcomes. Communication errors, inadequate training, and general organizational issues were the most recurrent factors contributing to the events. CONCLUSIONS: Risk mitigation during mass vaccination in temporary sites is an essential element of a successful vaccination campaign. The reporting of adverse events should be encouraged in order to obtain as much information as possible for a continuous improvement of the activity.

Correction: Cazzoletti et al. Risk Factors Associated with Nursing Home COVID-19 Outbreaks: A Retrospective Cohort Study. Int. J. Environ. Res. Public Health 2021, 18, 8434.

The authors would like to make the following corrections to this paper [...].

Risk Factors Associated with Nursing Home COVID-19 Outbreaks: A Retrospective Cohort Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic had a devastating impact on nursing homes/long-term care facilities. This study examined the relationship between geography, size, design, organizational characteristics, and implementation of infection prevention and control (IPC) measures and the extent of COVID-19 outbreaks in nursing homes in the Autonomous Province of Trento (Italy) during the time frame of March-May 2020. METHODS: The analysis included 57 nursing homes (5145 beds). The association between median cumulative incidence of COVID-19 cases among residents and characteristics of nursing homes was assessed by Mann-Whitney U test, Kruskal-Wallis test or Spearman rho. To evaluate the potential confounding of geographical area, a 2-level random intercept logistic model was fitted, with level 1 units (patients in nursing homes) nested into level 2 units (nursing homes), and "being a COVID-19 case" as the dependent variable. RESULTS: Median cumulative incidence was not significantly associated with any of the variables, except for geographical region (p = 0.002). COVID-19 cases clustered in the part of the province bordering the Italian region most affected by the pandemic (Lombardy) (45.2% median cumulative incidence). CONCLUSIONS: Structural/organizational factors and standard IPC measures may not predict the epidemiology of COVID-19 outbreaks and be sufficient alone to protect nursing homes against them.

SARS-CoV-2 Infection in Health Workers: Analysis from Verona SIEROEPID Study during the Pre-Vaccination Era.

BACKGROUND: To report the baseline phase of the SIEROEPID study on SARS-CoV-2 infection seroprevalence among health workers at the University Hospital of Verona, Italy, between spring and fall 2020; to compare performances of several laboratory tests for SARS-CoV-2 antibody detection. METHODS: 5299 voluntary health workers were enrolled from 28 April 2020 to 28 July 2020 to assess immunological response to SARS-CoV-2 infection throughout IgM, IgG and IgA serum levels titration by four laboratory tests. Association of antibody titre with several demographic variables, swab tests and performance tests (sensitivity, specificity, and agreement) were statistically analyzed. RESULTS: The overall seroprevalence was 6%, considering either IgG and IgM, and 4.8% considering IgG. Working in COVID-19 Units was not associated with a statistically significant increase in the number of infected workers. Cohen's kappa of agreement between MaglumiTM and VivaDiagTM was quite good when considering IgG only (Cohen's kappa = 78.1%, 95% CI 74.0-82.0%), but was lower considering IgM (Cohen's kappa = 13.3%, 95% CI 7.8-18.7%). CONCLUSION: The large sample size with high participation (84.7%), the biobank and the longitudinal design were significant achievements, offering a baseline dataset as the benchmark for risk assessment, health surveillance and management of SARS-CoV-2 infection for the hospital workforce, especially considering the ongoing vaccination campaign. Study results support the national regulator guidelines on using swabs for SARS-CoV-2 screening with health workers and using the serological tests to contribute to the epidemiological assessment of the spread of the virus.

Levels of burn-out among healthcare workers during the COVID-19 pandemic and their associated factors: a cross-sectional study in a tertiary hospital of a highly burdened area of north-east Italy.

OBJECTIVE: To determine burn-out levels and associated factors among healthcare personnel working in a tertiary hospital of a highly burdened area of north-east Italy during the COVID-19 pandemic. DESIGN: Observational study conducted from 21 April to 6 May 2020 using a web-based questionnaire. SETTING: Research conducted in the Verona University Hospital (Veneto, Italy). PARTICIPANTS: Out of 2195 eligible participants, 1961 healthcare workers with the full range of professional profiles (89.3%) completed the survey. PRIMARY OUTCOME MEASURE: Levels of burn-out, assessed by the Maslach Burnout Inventory-General Survey (MBI-GS). Multivariable logistic regression analysis was performed to identify factors associated with burn-out in each MBI-GS dimension (emotional exhaustion, EX; professional efficacy, EF; cynicism, CY). RESULTS: Overall, 38.3% displayed high EX, 46.5% low EF and 26.5% high CY. Burn-out was frequent among staff working in intensive care units (EX 57.0%; EF 47.8%; CY 40.1%), and among residents (EX 34.9%; EF 63.9%; CY 33.4%) and nurses (EX 49.2%; EF 46.9%; CY 29.7%). Being a resident increased the risk of burn-out (by nearly 2.5 times) in all the three MBI subscales and being a nurse increased the risk of burn-out in the EX dimension in comparison to physicians. Healthcare staff directly engaged with patients with COVID-19 showed more EX and CY than those working in non-COVID wards. Finally, the risk of burn-out was higher in staff showing pre-existing psychological problems, in those having experienced a COVID-related traumatic event and in those having experienced interpersonal avoidance in the workplace and personal life. CONCLUSIONS: Burn-out represents a great concern for healthcare staff working in a large tertiary hospital during the COVID-19 pandemic and its impact is more burdensome for front-line junior physicians. This study underlines the need to carefully address psychological well-being of healthcare workers to prevent the increase of burn-out in the event of a new COVID-19 healthcare emergency.

Health Surveillance and Response to SARS-CoV-2 Mass Testing in Health Workers of a Large Italian Hospital in Verona, Veneto

Italy presented the first largest COVID-19 outbreak outside of China. Veneto currently ranks fourth among the Italian regions for COVID-19 confirmed cases (~19,000). This study presents health surveillance data for SARS-CoV-2 in 6100 health workers (HW) employed in a large public hospital. Workers underwent oropharyngeal and nasopharyngeal swabs, with a total of 5942 participants (97.5% of the population). A total of 11,890 specimens were tested for SARS-CoV-2 infection using PCR, identifying the viral genes E, RdRP, and N. Positive tests were returned for 238 workers (cumulative incidence of 4.0%, similar in both COVID and nonCOVID units). SARS-CoV-2 risk was not affected by gender, age, or job type, whereas work setting and occupation were both predictors of infection. The risk was higher in medical wards (OR 2.7, 95% CI 1.9-3.9) and health services (OR 4.3, 95% CI 2.4-7.6), and lower in surgical wards and administration areas. To our knowledge, this study represents the largest available HW case list swab-tested for SARS-CoV-2, covering almost the total workforce. Mass screening enabled the isolation of HW, improved risk assessment, allowed for close contacts of and infected HW to return to work, provided evidence of SARS-CoV-2 diffusion, and presented solid ground to prevent nosocomial SARS-CoV-2 infections. The ongoing concurrent sero-epidemiological study aims to enable the improvement of health surveillance to maintain the safety of HWs and the communities they serve.