Occupational risk of SARS-CoV-2 infection and reinfection during the second pandemic surge: a cohort study

Health Care Personnel Workdays Lost and Direct Health Care Salary Costs Incurred due to COVID-19 Infection in the Age of Widespread Vaccine Availability

BACKGROUND

Vaccination against coronavirus disease 2019 (COVID-19) can mitigate the burden of health care worker (HCW) infection. We investigate the burden of HCW illness and its associated direct health care personnel costs in the setting of widespread vaccine availability and explore factors influencing these outcomes.

METHODS

This multicenter prospective study followed HCWs over an 8-month period from January to August 2023. Data recorded included incident COVID-19 infection, symptom burden, workdays missed, and vaccine history. Workdays lost due to illness were used to calculate direct health care personnel costs due to COVID-19 infection. Univariate analysis and multivariable regression investigated the factors associated with workdays lost and direct health care personnel.

RESULTS

In total, 1218 participants were enrolled and followed for 8 months, with 266 incidents of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, 1191 workdays lost, and health care personnel costs of €397 974. Multivariable regression revealed that workdays lost were associated with incomplete primary COVID-19 vaccination course. Being unvaccinated, older age, and male were associated with increased health care personnel costs.

CONCLUSIONS

Health care workdays lost remain a significant issue and are associated with health care system burden despite vaccine availability. These can be mitigated via targeted implementation of vaccine programs. Seasonal variation in health care workdays lost should inform workforce planning to accommodate surge periods.

SARS-CoV-2 Reinfection Cases in a Household-Based Prospective Cohort in Rio de Janeiro

This was a household-based prospective cohort study conducted in Rio de Janeiro, in which people with laboratory-confirmed coronavirus disease 2019 (COVID-19) and their household contacts were followed from April 2020 through June 2022. Ninety-eight reinfections were identified, with 71 (72.5%) confirmed by genomic analyses and lineage definition in both infections. During the pre-Omicron period, 1 dose of any COVID-19 vaccine was associated with a reduced risk of reinfection, but during the Omicron period not even booster vaccines had this effect. Most reinfections were asymptomatic or milder in comparison with primary infections, a justification for continuing active surveillance to detect infections in vaccinated individuals. Our findings demonstrated that vaccination may not prevent infection or reinfection with severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). Therefore we highlight the need to continuously update the antigenic target of SARS CoV-2 vaccines and administer booster doses to the population regularly, a strategy well established in the development of vaccines for influenza immunization programs.

The longitudinal study of subjective wellbeing and absenteeism of healthcare workers considering post-COVID condition and the COVID-19 pandemic toll

Experts have warned against the pandemic burden on healthcare workers early on, however little is known about the evolution of this burden with time, in addition to the long-term effects of post-COVID symptoms in healthcare workers. Staff at the Geneva University Hospitals in Switzerland had an online follow-up in July and December 2021, on their physical and mental health, quality of life and functional capacity using validated scales. Descriptive analyses compared the prevalence of symptoms, functional impairment and quality of life in SARS-CoV-2 positive and negative individuals at baseline and at follow-up. Out of the initial n = 3,083 participants that answered at baseline in July 2021, n = 900 (mean age of 46.4 years, 70.1% women) completed the follow-up in December 2021. With time, more individuals reported fatigue (+ 9.4%), headache (+ 9.0%), insomnia (+ 2.3%), cognitive impairment (+ 1.4%), stress/burnout (+ 8.8%), pain (+ 8.3%), digestive symptoms (+ 3.6%), dyspnea (+ 1.0%), and cough (+ 7.7%) compared to baseline, with a differentially larger increase in symptoms in the SARS-CoV-2 negative group. Individuals had more functional impairment (12.7% at baseline and 23.9% at follow-up), with more absenteeism and worsening quality of life. Healthcare workers are potentially suffering from long term consequences of the pandemic burden, calling for urgent action and solutions.

The Protection of Naturally Acquired Antibodies Against Subsequent SARS-CoV-2 Infection: A Systematic Review and Meta-Analysis

The specific antibodies induced by SARS-CoV-2 infection may provide protection against a subsequent infection. However, the efficacy and duration of protection provided by naturally acquired immunity against subsequent SARS-CoV-2 infection remain controversial. We systematically searched for the literature describing COVID-19 reinfection published before 07 February 2022. The outcomes were the pooled incidence rate ratio (IRR) for estimating the risk of subsequent infection. The Newcastle–Ottawa Scale (NOS) was used to assess the quality of the included studies. Statistical analyses were conducted using the R programming language 4.0.2. We identified 19 eligible studies including more than 3.5 million individuals without the history of COVID-19 vaccination. The efficacy of naturally acquired antibodies against reinfection was estimated at 84% (pooled IRR = 0.16, 95% CI: 0.14-0.18), with higher efficacy against symptomatic COVID-19 cases (pooled IRR = 0.09, 95% CI = 0.07-0.12) than asymptomatic infection (pooled IRR = 0.28, 95% CI = 0.14-0.54). In the subgroup analyses, the pooled IRRs of COVID-19 infection in health care workers (HCWs) and the general population were 0.22 (95% CI = 0.16-0.31) and 0.14 (95% CI = 0.12-0.17), respectively, with a significant difference (P = 0.02), and those in older (over 60 years) and younger (under 60 years) populations were 0.26 (95% CI = 0.15–0.48) and 0.16 (95% CI =  0.14-0.19), respectively. The risk of subsequent infection in the seropositive population appeared to increase slowly over time. In conclusion, naturally acquired antibodies against SARS-CoV-2 can significantly reduce the risk of subsequent infection, with a protection efficacy of 84%.

Registration number: CRD42021286222

Risk of reinfection and disease after SARS-CoV-2 primary infection: Meta-analysis

INTRODUCTION

A precise estimate of the frequency and severity of SARS-CoV-2 reinfections would be critical to optimize restriction and vaccination policies for the hundreds of millions previously infected subjects. We performed a meta-analysis to evaluate the risk of reinfection and COVID-19 following primary infection.

METHODS

We searched MedLine, Scopus and preprint repositories for cohort studies evaluating the onset of new infections among baseline SARS-CoV-2-positive subjects. Random-effect meta-analyses of proportions were stratified by gender, exposure risk, vaccination status, viral strain, time between episodes, and reinfection definition.

RESULTS

Ninety-one studies, enrolling 15,034,624 subjects, were included. Overall, 158,478 reinfections were recorded, corresponding to a pooled rate of 0.97% (95% CI: 0.71%-1.27%), with no substantial differences by definition criteria, exposure risk or gender. Reinfection rates were still 0.66% after ≥12 months from first infection, and the risk was substantially lower among vaccinated subjects (0.32% vs. 0.74% for unvaccinated individuals). During the first 3 months of Omicron wave, the reinfection rates reached 3.31%. Overall rates of severe/lethal COVID-19 were very low (2-7 per 10,000 subjects according to definition criteria) and were not affected by strain predominance.

CONCLUSIONS

A strong natural immunity follows the primary infection and may last for more than one year, suggesting that the risk and health care needs of recovered subjects might be limited. Although the reinfection rates considerably increased during the Omicron wave, the risk of a secondary severe or lethal disease remained very low. The risk-benefit profile of multiple vaccine doses for this subset of population needs to be carefully evaluated.

SARS-CoV-2 seropositivity and subsequent infection risk: a prospective cohort study

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Subsequent infection risk with SARS-CoV-2 is currently not very well understood.

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An 8-month follow-up demonstrated that subsequent SARS-CoV-2 infections were uncommon.

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Antibody concentration potentially influences the risk of subsequent infection.

Objectives

This aim of this study was to examine the relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seropositivity and subsequent infection.

Design

A cohort study design was employed.

Methods

Stratified random sampling was undertaken to identify individuals aged 10 years and above registered with Qatar's largest primary healthcare provider. A questionnaire was administered, and blood samples were collected and analyzed for immunoglobulin G antibodies against SARS-CoV-2 at baseline. Participants were followed up until March 31, 2021 (a 34-week follow-up period) for vaccination status and a positive polymerase chain reaction (PCR) test for SARS-CoV-2.

Results

A total of 2044 individuals participated in the study (97.2% of the planned sample). Of these, 185 (9%) were found to be seropositive at baseline. 450 individuals were vaccinated during the follow-up period — 246 with one dose and 204 with two doses. 86 (4.2%) individuals had a positive PCR test during the follow-up period, of which 80 (3.9%) were seronegative and six (0.3%) were seropositive (five undiluted and one with a titer ≥ 1:8).

Conclusions

Overall, the findings suggest that reinfections are uncommon. Antibody concentrations potentially influence the risk of subsequent infection. Therefore, it might not be necessary to subject seropositive individuals to vaccination and the quarantine policies that apply to seronegative individuals.