An Epidemiological Cohort Study of SARS-CoV-2 and COVID-19 in German Healthcare Workers – Interim Analysis After Six Months of Follow-Up

(1) Background: Healthcare workers (HCWs) are prone to intensified exposure to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the ongoing pandemic. We prospectively analyzed the prevalence of antibodies against SARS-CoV-2 in HCWs at baseline and follow up with regard to clinical signs and symptoms in two university hospitals in Brandenburg, Germany. (2) Methods: Screening for anti-SARS-CoV-2 IgA and IgG antibodies was offered to HCWs at baseline and follow up two months thereafter in two hospitals of Brandenburg Medical School during the first wave of the COVID-19 pandemic in Germany in an ongoing observational cohort study. Medical history and signs and symptoms were recorded by questionnaires and analyzed. (3) Results: Baseline seroprevalence of anti-SARS-CoV-2 IgA was 11.7% and increased to 15% at follow up, whereas IgG seropositivity was 2.1% at baseline and 2.2% at follow up. The rate of asymptomatic seropositive cases was 39.5%. Symptoms were not associated with general seropositivity for anti-SARS-CoV-2; however, class switch from IgA to IgG was associated with increased symptom burden. (4) Conclusions: The seroprevalence of antibodies against SARS-CoV-2 was low in HCWs but higher compared to population data and increased over time. Screening for antibodies detected a significant proportion of seropositive participants cases without symptoms.

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Prospective Epidemiological Cohort Study of Reduced Risk for Incident Cataract with Vigorous Physical Activity and Cardiorespiratory Fitness during a 7-Year Follow-up

Investigative Opthalmology & Visual Science ◽

10.1167/iovs.08-1797 ◽

2009 ◽

Vol 50 (1) ◽

pp. 95 ◽

Cited By ~ 23

Author(s):

Paul T. Williams

Keyword(s):

Physical Activity ◽

Cohort Study ◽

Cardiorespiratory Fitness ◽

Vigorous Physical Activity ◽

Epidemiological Cohort ◽

Reduced Risk

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COVID-19 vaccine effectiveness among healthcare workers in Portugal: results from a hospital-based cohort study, December 2020 to November 2021

10.1101/2022.01.07.22268889 ◽

2022 ◽

Author(s):

Vânia Gaio ◽

Adriana Silva ◽

Palmira Amaral ◽

João Faro Viana ◽

Pedro Pinto Leite ◽

...

Keyword(s):

Cohort Study ◽

Healthcare Workers ◽

Vaccine Effectiveness ◽

Symptomatic Infection ◽

Cox Models ◽

Mainland Portugal ◽

Hazard Ratios ◽

Group Sex ◽

Tagus Valley

Introduction: Healthcare workers (HCW) were amongst the first prioritized for COVID-19 vaccination but data on COVID–19 vaccine effectiveness among HCW is still limited. This study aims to estimate the COVID–19 vaccine effectiveness (VE) against SARS–CoV–2 symptomatic infection among HCW from Portuguese hospitals. Methods: In this prospective cohort study, we analysed data from HCW (all professional categories) from two central hospitals in the Lisbon and Tagus Valley and Centre regions of mainland Portugal between December 2020 and November 2021. VE against symptomatic SARS–CoV–2 infection was estimated as one minus the confounder adjusted hazard ratios by Cox models considering age group, sex, presence of chronic disease and occupational exposure to patients diagnosed with COVID–19 as adjustment variables. Results: During the 11 months of follow up, the 2213 HCW contributed a total of 1950 person-years at risk and 171 SARS–CoV–2 events occurred. The COVID–19 incidence rate for unvaccinated HCW was 348.7 per 1000 person-years while for fully vaccinated HCW was 43.0 per 1000 person-years. We observed a VE against symptomatic SARS–CoV–2 infection of 73.9% (95% CI: 26.2–90.8%) for complete vaccination status. Conclusion: This cohort study found a high COVID-19 VE against symptomatic SARS–CoV–2 infection in Portuguese HCW, which is in concordance with previous studies from other countries. Monitoring of VE in this HCW cohort continues during the winter 2021/2022 to evaluate potential VE decay and booster vaccine effect. Keywords: Vaccine effectiveness, SARS–CoV–2 , COVID–19, symptomatic infection, healthcare workers.

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Incidence of Asymptomatic and Symptomatic Influenza Among Healthcare Workers: A Multicenter Prospective Cohort Study

Clinical Infectious Diseases ◽

10.1093/cid/ciaa1109 ◽

2020 ◽

Author(s):

Thomas Bénet ◽

Sélilah Amour ◽

Martine Valette ◽

Mitra Saadatian-Elahi ◽

Ludwig Serge Aho-Glélé ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Cumulative Incidence ◽

Prospective Cohort ◽

Healthcare Workers ◽

Control Measures ◽

T1 And T2 ◽

Multicenter Prospective Cohort Study ◽

Multicenter Prospective Cohort

Abstract Background Influenza is an important cause of viral hospital-acquired infection involving patients, healthcare workers (HCW), and visitors. The frequency of asymptomatic influenza among HCW with possible subsequent transmission is poorly described. The objective is to determine the cumulative incidence of asymptomatic, paucisymptomatic, and symptomatic influenza among HCW. Method A multicenter prospective cohort study was done in 5 French university hospitals, including 289 HCW during the 2016–2017 influenza season. HCW had 3 physical examinations (time [T] 0, before epidemic onset; T.1, before epidemic peak; T.2, T.3, after epidemic peak). A blood sample was taken each time for influenza serology and a nasal swab was collected at T1 and T2 for influenza detection by polymerase chain reaction (PCR). Positive influenza was defined as either a positive influenza PCR, and/or virus-specific seroconversion against influenza A, the only circulating virus, with no vaccination record during follow-up. Symptoms were self-reported daily between T1 and T2. Cumulative incidence of influenza was stratified by clinical presentation per 100 HCW. Results Of the 289 HCW included, 278 (96%) completed the entire follow-up. Overall, 62 HCW had evidence of influenza of whom 46.8% were asymptomatic, 41.9% were paucisymptomatic, and 11.3% were symptomatic. Cumulative influenza incidence was 22.3% (95% confidence interval [CI]: 17.4%–27.2%). Cumulative incidence of asymptomatic influenza was 5.8% (95% CI: 3.3%–9.2%), 13.7% (95% CI: 9.9%–18.2%) for paucisymptomatic influenza, and 2.9% (95% CI: 1.3%–5.5%) for symptomatic influenza. Conclusions Asymptomatic and paucisymptomatic influenza were frequent among HCW, representing 47% and 42% of the influenza burden, respectively. These findings highlight the importance of systematic implementation of infection control measures among HCW regardless of respiratory symptoms from preventing nosocomial transmission of influenza. Clinical Trials Registration NCT02868658.

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Serologic Status and SARS CoV-2 Infection over 6-Months of Follow-Up in Healthcare Workers in Chicago: A Cohort Study

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2021.367 ◽

2021 ◽

pp. 1-29

Author(s):

John T. Wilkins ◽

Lisa R. Hirschhorn ◽

Elizabeth L. Gray ◽

Amisha Wallia ◽

Mercedes Carnethon ◽

...

Keyword(s):

Cohort Study ◽

Rate Ratio ◽

Healthcare Workers ◽

Infection Rates ◽

Online Surveys ◽

Chicago Area ◽

Adjusted Rate ◽

Adjusted Rate Ratio ◽

Serology Testing

Abstract Objective: To determine the changes in SARS-CoV-2 serologic status and SARS-CoV-2 infection rates in healthcare workers (HCW) over 6-months of follow-up. Design: Prospective cohort study Setting and Participants: HCW in the Chicago area, USA Methods: Cohort participants were recruited in May/June 2020 for baseline serology testing (Abbott anti-Nucleocapsid IgG) and were then invited for follow-up serology testing 6 months later. Participants completed monthly online surveys which assessed demographics, medical history, COVID-19 illness, and exposures to SARS-CoV-2. The electronic medical record was used to identify SARS-CoV-2 PCR positivity during follow-up. Serologic conversion and SARS-CoV-2 infection or possible reinfection rates (cases per 10,000 person*days) by antibody status at baseline and follow-up were assessed. Results: 6510 HCW were followed for a total of 1,285,395 person*days (median follow-up, 216 days). For participants who had baseline and follow-up serology checked, 285 (6.1%) of the 4681 seronegative participants at baseline seroconverted to positive at follow-up; 138 (48%) of the 263 who were seropositive at baseline were seronegative at follow-up. When analyzed by baseline serostatus alone, 519 (8.4%) of 6194 baseline seronegative cohort participants had a positive PCR after baseline serology testing (rate = 4.25/10,000 person days). Of 316 participants who were seropositive at baseline, 8 (2.5%) met criteria for possible SARS-CoV-2 reinfection (PCR+ more than 90 days after baseline serology) during follow-up representing a rate of 1.27/10,000 days at risk. The adjusted rate ratio for possible reinfection in baseline seropositive compared to infection in baseline seronegative participants was 0.26, (95%CI: 0.13 – 0.53). Conclusions: Seropositivity in HCWs is associated with moderate protection from future SARS-CoV-2 infection.

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Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort study

BMJ Open ◽

10.1136/bmjopen-2021-050824 ◽

2021 ◽

Vol 11 (6) ◽

pp. e050824

Author(s):

Laure Mortgat ◽

Kristien Verdonck ◽

Veronik Hutse ◽

Isabelle Thomas ◽

Cyril Barbezange ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Healthcare Workers ◽

Vaccination Strategy ◽

Control Measures ◽

Infection Prevention And Control ◽

Online Questionnaire ◽

Reverse Transcription Pcr

ObjectivesTo describe prevalence and incidence of anti-SARS-CoV-2 antibodies among Belgian hospital healthcare workers (HCW) in April–December 2020.DesignProspective cohort study. Follow-up was originally planned until September and later extended.SettingMulticentre study, 17 hospitals.Participants50 HCW were randomly selected per hospital. HCW employed beyond the end of the study and whose profession involved contact with patients were eligible. 850 HCW entered the study in April–May 2020, 673 HCW (79%) attended the September visit and 308 (36%) the December visit.Outcome measuresA semiquantitative ELISA was used to detect IgG against SARS-CoV-2 in serum (Euroimmun) at 10 time points. In seropositive samples, neutralising antibodies were measured using a virus neutralisation test. Real-time reverse transcription PCR (RT-qPCR) was performed to detect SARS-CoV-2 on nasopharyngeal swabs. Participant characteristics and the presence of symptoms were collected via an online questionnaire.ResultsAmong all participants, 80% were women, 60% nurses and 21% physicians. Median age was 40 years. The seroprevalence remained relatively stable from April (7.7% (95% CI: 4.8% to 12.1%) to September (8.2% (95% CI: 5.7% to 11.6%)) and increased thereafter, reaching 19.7% (95% CI: 12.0% to 30.6%) in December 2020. 76 of 778 initially seronegative participants seroconverted during the follow-up (incidence: 205/1000 person-years). Among all seropositive individuals, 118/148 (80%) had a positive neutralisation test, 83/147 (56%) presented or reported a positive RT-qPCR, and 130/147 (88%) reported COVID-19-compatible symptoms at least once. However, only 46/73 (63%) of the seroconverters presented COVID-19-compatible symptoms in the month prior to seroconversion.ConclusionsThe seroprevalence among hospital HCW was slightly higher than that of the general Belgian population but followed a similar evolution, suggesting that infection prevention and control measures were effective and should be strictly maintained. After two SARS-CoV-2 waves, 80% of HCW remained seronegative, justifying their prioritisation in the vaccination strategy.Trial registration numberNCT04373889

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Sustained negative mental health outcomes among healthcare workers over the first year of the COVID-19 pandemic: a prospective cohort study

10.1101/2021.11.21.21266594 ◽

2021 ◽

Author(s):

Roberto Mediavilla ◽

Eduardo Fernandez-Jimenez ◽

Irene Martinez-Morata ◽

Fabiola Jaramillo ◽

Jorge Andreo-Jover ◽

...

Keyword(s):

Mental Health ◽

Cohort Study ◽

Psychological Distress ◽

Health Outcomes ◽

Healthcare Workers ◽

Mental Health Problems ◽

Mental Health Outcomes ◽

Depression Symptoms ◽

Over Time

Objective: To characterize the evolution of healthcare workers' mental health status over the 1-year period following the initial COVID-19 pandemic outbreak and to examine baseline characteristics associated with resolution or persistence of mental health problems over time. Methods: We conducted an 8-month follow-up cohort study. Eligible participants were healthcare workers working in Spain. Baseline data were collected during the initial pandemic outbreak. Survey-based self-reported measures included COVID-19-related exposures, sociodemographic characteristics, and three mental health outcomes (psychological distress, depression symptoms, and posttraumatic stress disorder symptoms). We examined three longitudinal trajectories in mental health outcomes between baseline and follow-up assessments (namely asymptomatic/stable, recovering, and persistently symptomatic/worsening). Results: We recruited 1,807 participants. Between baseline and follow-up assessments, the proportion of respondents screening positive for psychological distress and probable depression decreased, respectively, from 74% to 56% and from 28% to 21%. Two-thirds remained asymptomatic/stable in terms of depression symptoms and 56% remained symptomatic or worsened over time in terms of psychological distress. Conclusions: Poor mental health outcomes among healthcare workers persisted over time. Occupational programs and mental health strategies should be put in place.

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Immunogenicity of COVID-19 Vaccination in Immunocompromised Patients: An Observational, Prospective Cohort Study Interim Analysis

10.1101/2021.06.28.21259576 ◽

2021 ◽

Author(s):

Ghady Haidar ◽

Mounzer Agha ◽

Amy Lukanski ◽

Kelsey Linstrum ◽

Rachel Troyan ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Interim Analysis ◽

Healthcare Workers ◽

Hematological Malignancies ◽

Solid Organ ◽

Immunocompromised Patients ◽

Observational Prospective Cohort Study ◽

Antibody Levels

Objectives: Immunocompromised patients were excluded from COVID-19 vaccine clinical trials. The objectives of the study were to measure antibody responses, levels, and neutralization capability after COVID-19 vaccination among immunocompromised patients and compare these variables to those of immunocompetent healthcare workers. Methods This is an interim analysis of an ongoing observational, prospective cohort study which launched on April 14, 2021 across Western Pennsylvania. Participants were healthy healthcare workers (HCW) and immunocompromised patients who had completed their COVID-19 vaccination series. Individuals with a history of COVID-19 were not eligible. Serum was collected to measure for the presence of IgG against the SARS-CoV-2 Spike protein using a semi-quantitative assay; antibody levels were available for comparisons. A quasi-random subset of patients was selected for pseudovirus neutralization assays. Seropositivity with 95% Clopper-Pearson exact confidence intervals and distribution of antibody levels were measured. To identify risk factors for seronegativity, clinical characteristics were univariately compared between antibody reactive and non-reactive individuals within the immunocompromised group. Results: 107 HCW and 489 immunocompromised patients were enrolled. Compared to HCWs, seropositivity was significantly lower (p<.001) among immunocompromised patients with Solid organ transplant (SOT), autoimmune, hematological malignancies, and solid tumors (HCW=98.1%; SOT=37.2%; autoimmune=83.8%; hematological malignancies=54.7%; and solid tumor=82.4%, p < 0.05). Over 94% of patients with Human Immunodeficiency Virus were seropositive. Among seropositive patients, antibody levels were much lower among SOT (4.5 [2.1,13.1], p=.020). Neutralization titers tightly correlated with antibody levels (Spearman r = 0.91, p < 0.0001). Conclusion: Our findings demonstrate the heterogeneity of the humoral immune response to COVID-19 vaccines based on underlying immunosuppressive condition and highlight an urgent need to optimize and individualize COVID-19 prevention in these patients. These findings also have implications on public health guidance, particularly given revised Centers for Disease Control and Prevention recommendations permitting vaccinated individuals to abandon masking and social distancing in most settings. Future studies are warranted to determine assessment of cellular immunity, longitudinal measurement of immune responses, and the safety and efficacy of revaccination.

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