Seroprevalence of SARS-CoV-2 antibody among healthcare workers in a university hospital in Mallorca, Spain, during the first wave of the COVID-19 pandemic

Dynamics of SARS-CoV-2 Immunoglobulin G Antibody Among Hospitalized Patients and Healthcare Workers During the Delta Wave in Bangladesh

BACKGROUND

 A reliable marker of COVID-19 past infection is the anti-spike IgG antibody (Ab) titer of the SARS-CoV-2 virus, which may be identified even one year from diagnosis. Serology can be effective in diagnosing asymptomatic infection and patients with negative reverse transcription polymerase chain reaction. Exploring these dynamics and the persistence of antibodies is vital to understanding the disease process.

MATERIALS AND METHODS

 We designed this observational study to compare the seroconversion status of COVID-19 patients to healthy healthcare workers. The total number of participants was 272, including 58 hospitalized (recovered) patients, 153 healthcare workers (HCWs), and 61 control populations from the community. A total of 404 samples were taken for IgG titer measurements using the enzyme-linked immunosorbent assay method.

RESULTS

 Among 58 COVID-19 patients, 58.6% were men, and the male-to-female ratio was 1:1.41. All hospitalized patients had three months of persistence of Ab titer. The median IgG titer (interquartile range) optical density values for the hospitalized severe group on day 0, as well as during the fourth, eighth, and twelfth weeks, were 9.25 (6.01-11.893), 8.95 (5.52-12.42), 13.19 (12.26-13.26), and 12.99 (9.23-13.24), respectively. In comparison, the nonsevere group exhibited median values of 4.19 (3.08-9.89), 6.99 (4.32-9.75), 8.65 (5.83-13.08), and 12.48 (7.88-13.16), respectively. However, seroprevalence was higher in the control group (83.3%); in the HCWs, it was 54.9%. Although patients with severe disease had higher antispike IgG titers, no difference in titers was seen among age, gender, body mass index, or diabetes subgroups.

CONCLUSION

 We observed Ab titer persistence up to three months in cases of COVID-19-recovered patients, whereas seroprevalence was high among HCWs and the control group during the Delta wave.

Seroprevalence and indexes of IgG antibodies for SARS-CoV-2 infection among People Living With HIV, tuberculosis patients and healthcare workers, in Salvador, Brazil

INTRODUCTION

COVID-19 can trigger different clinical presentations in distinct population groups, some of which are considered at higher risk of SARS-CoV-2 infection. Little is known about the susceptibility of certain populations to the infection.

OBJECTIVES

We aimed to determine the prevalence of COVID-19 among People Living With HIV/AIDS (PLWH) attending a tertiary public hospital in Salvador, Brazil, patients with active pulmonary tuberculosis and Hospital's Healthcare Workers (HCW), and to compare their SARS-CoV-2 antibody levels.

METHODS

In this observational study we included 2294 participants from June 9, 2020 to August 10, 2021. IgG SARS-CoV-2 antibodies from all participants (275 PLWH, 42 with active tuberculosis and 1977 healthcare workers) were measured. Prevalence of COVID-19 and antibodies indexes were compared across groups.

RESULTS

We detected a higher prevalence of COVID-19 in patients with active tuberculosis (42.9%) than in PLWH (22.5%) or HCW (11.7%). Previously vaccinated participants with a COVID-19 history had median higher IgG antibody indexes (8.2; IQR: 5.5‒10) than those vaccinated who did not have COVID-19 until the time of this study (4.1; IQR: 1.6‒6.2, p < 0.001).

CONCLUSION

Prevalence of previous SARS-CoV-2 infection was higher among tuberculosis patients than that found in HCW and PLWH, but antibodies levels were similar across groups.

Seroprevalence of SARS-CoV2 Infections in Health Care Personnel in a Long-Term Care Institution After the First Wave of the Pandemic: A Cross-Sectional Study

BACKGROUND

At the time of our study, occupational health evidence specific for long-term care employees was mostly lacking. The purpose of this study was to determine the proportion of positive cases in employees after the first COVID-19 wave in May 2020. We also determined the prevalence of asymptomatic cases.

METHOD

The study population included all health care workers (HCW) employed at one mid-size long-term hospital in Spain (May 2020). A cross-sectional study design included an interviewer-administered self-reported questionnaire (including sociodemographic questions, risk factors for COVID-19 complications such as hypertension or diabetes, and previous polymerase chain reaction [PCR] results) and antibody determination (Biozek rapid test). Data were analyzed using Student's t, Fisher, and chi-square tests. Two multivariate logistic models were created to evaluate exposure factors and symptoms separately on the outcome of having had COVID-19.

FINDINGS

Of the 97% of workers who participated (580/596), 300 (51.7%) suffered symptoms of COVID-19, 161 (27.8%) of the rapid antibody tests were positive for IgM and/or IgG, 160 (27.6%) workers had at least one risk factor, and 32 (19.0%) of the 168 SARS-CoV-2-positive cases were asymptomatic. The proportion of negative or unavailable PCRs, with positive antibody, was 11.7% (56/477). Casual contact without protection (odds ratio [OR]: 1.9, 95% confidence interval [CI]: 1.1-3.4), doctor occupation (OR 3.3, 95% CI: 1.1-10.2), and nursing assistant occupation (OR 2.5, 95% CI: 1.2-5.8) were independently associated with SARS-CoV-2 infection.

CONCLUSION

Physicians and nursing assistants in a long-term care setting were at a higher risk of SARS-COV-2 infection over other occupations in the first wave of the pandemic, especially when in contact with patients without protection. Almost one-fifth of the workers with a positive PCR test for SARS-COV-2 were asymptomatic and seroprevalence (27.8%) was well below the approximated herd immunity cutoff (60-70%). Essential workers in long-term care must be monitored frequently by Employee Health Service and should be required to wear personal protective equipment including a fit-tested N-95 while in close contact with patients and coworkers.

Seroprevalence of SARS-CoV-2 in a Fully Operative Dentistry Academic Center in Madrid (Spain) During the De-escalation Phase of the COVID-19 Pandemic. Are Our Dentists at Greater Risk?

PURPOSE

To determine the prevalence of COVID-19 infection among dental professionals at an Academic Center in Madrid (Spain) at the beginning of the pandemic's de-escalation phase.

MATERIALS AND METHODS

A cross-sectional study was designed. COVID-19 infection was determined by membrane-based immunoassay qualitative detection of IgG and IgM antibodies in human whole blood. Age, sex, race and professional qualification were recorded, as were symptoms compatible with COVID-19 infection whenever present. Data collected were analysed by means of descriptive and qualitative (X2) statistical analyses.

RESULTS

A total of 195 individuals were included (40 administrative professionals and 155 dentists). Seroprevalence at the end of the de-escalation phase was 20.0% among all the participants. The highest prevalence was found among the orthodontists (34.8%), followed by the paediatric dentists (28.6%) and oral surgeons (14.7%). Most subjects were positive for IgG and negative for IgM (79.5%).

CONCLUSIONS

The seroprevalence of SARS-CoV-2 among dental professionals at the end of the de-escalation phase after the first wave of the pandemic was almost double the seroprevalence of the general population. Orthodontists had the highest rates of SARS-CoV-2 infection.

Detection of silent infection of severe acute respiratory syndrome coronavirus 2 by serological tests

Background

To control COVID-19 pandemic is of critical importance to the global public health. To capture the prevalence in an accurate and timely manner and to understand the mode of nosocomial infection are essential for its preventive measure.

Methods

We recruited 685 healthcare workers (HCW’s) at Tokyo Shinagawa Hospital prior to the vaccination with COVID-19 vaccine. Sera of the subjects were tested by assays for the titer of IgG against S protein’s receptor binding domain (IgG (RBD)) or IgG against nucleocapsid protein (IgG (N)) of SARS-CoV-2. Together with PCR data, the positive rates by these methods were evaluated.

Results

Overall positive rates among HCW’s by PCR, IgG (RBD), IgG (N) with a cut-off of 1.4 S/C (IgG (N)_1.4), and IgG (N) with a cut-off of 0.2 S/C (IgG (N)_0.2) were 3.5%, 9.5%, 6.1%, and 27.7%, respectively. Positive rates of HCW’s working in COVID-19 ward were significantly higher than those of HCW’s working in non-COVID-19 ward by all the four methods. Concordances of IgG (RBD), IgG (N)_1.4, and IgG (N)_0.2 against PCR were 97.1%, 71.4%, and 88.6%, respectively. By subtracting the positive rates of PCR from that of IgG (RBD), the rate of overall silent infection and that of HCW’s in COVID-19 ward were estimated to be 6.0% and 21.1%, respectively.

Conclusions

For the prevention of nosocomial infection of SARS-CoV-2, identification of silent infection is essential. For the detection of ongoing infection, periodical screening with IgG (RBD) in addition to PCR would be an effective measure. For the surveillance of morbidity in the population, on the other hand, IgG (N)_0.2 could be the most reliable indicator among the three serological tests.

COVID-19 among workers of a comprehensive cancer centre between first and second epidemic waves (2020): a seroprevalence study in Catalonia, Spain

OBJECTIVES

Patients with cancer are at higher risk for severe COVID-19 infection. COVID-19 surveillance of workers in oncological centres is crucial to assess infection burden and prevent transmission. We estimate the SARS-CoV-2 seroprevalence among healthcare workers (HCWs) of a comprehensive cancer centre in Catalonia, Spain, and analyse its association with sociodemographic characteristics, exposure factors and behaviours.

DESIGN

Cross-sectional study (21 May 2020-26 June 2020).

SETTING

A comprehensive cancer centre (Institut Català d'Oncologia) in Catalonia, Spain.

PARTICIPANTS

All HCWs (N=1969) were invited to complete an online self-administered epidemiological survey and provide a blood sample for SARS-CoV-2 antibodies detection.

PRIMARY OUTCOME MEASURE

Prevalence (%) and 95% CIs of seropositivity together with adjusted prevalence ratios (aPR) and 95% CI were estimated.

RESULTS

A total of 1266 HCWs filled the survey (participation rate: 64.0%) and 1238 underwent serological testing (97.8%). The median age was 43.7 years (p25-p75: 34.8-51.0 years), 76.0% were female, 52.0% were nursing or medical staff and 79.0% worked on-site during the pandemic period. SARS-CoV-2 seroprevalence was 8.9% (95% CI 7.44% to 10.63%), with no differences by age and sex. No significant differences in terms of seroprevalence were observed between onsite workers and teleworkers. Seropositivity was associated with living with a person with COVID-19 (aPR 3.86, 95% CI 2.49 to 5.98). Among on-site workers, seropositive participants were twofold more likely to be nursing or medical staff. Nursing and medical staff working in a COVID-19 area showed a higher seroprevalence than other staff (aPR 2.45, 95% CI 1.08 to 5.52).

CONCLUSIONS

At the end of the first wave of the pandemic in Spain, SARS-CoV-2 seroprevalence among Institut Català d'Oncologia HCW was lower than the reported in other Spanish hospitals. The main risk factors were sharing household with infected people and contact with COVID-19 patients and colleagues. Strengthening preventive measures and health education among HCW is fundamental.

Características de profissionais de saúde acometidos por Covid-19: revisão integrativa da literatura

RESUMO O objetivo do estudo consistiu em identificar as características de profissionais de saúde acometidos por Covid-19. Trata-se de uma revisão integrativa da literatura guiada por seis etapas e que pesquisou cinco fontes de dados. Após o estabelecimento do fluxo de seleção do material levantado (N=5.522), determinou-se a amostra de artigos analisada (n=30). Desta, foram sintetizadas informações a respeito das características dos trabalhadores e relativas ao acometimento por Covid-19. Entre os estudos selecionados, foram compilados dados de 10.760 trabalhadores de saúde, predominantemente da equipe de enfermagem (27,3%) e médicos (13,2%). A maior parte (n=20; 66,6%) dos estudos atestou que os profissionais de saúde foram contaminados no ambiente de trabalho, principalmente hospitalar. A testagem por RT-PCR foi o principal método diagnóstico. Alguns estudos (n=16; 53,3%) relataram comorbidades prévias entre os trabalhadores. Os principais sintomas da Covid-19 nos profissionais de saúde acometidos foram: febre, tosse, fadiga e mialgia. Constataram-se características que remontam em perfil concentrado de enfermeiras e médicos contaminados no hospital. Essa realidade foi focalizada entre pesquisas transversais chinesas, italianas e estadunidenses.

Risk Groups for SARS-CoV-2 Infection among Healthcare Workers: Community Versus Hospital Transmission

BACKGROUND

We aimed to detect the risk factors for SARS-CoV-2 infection among healthcare workers (HCWs) in 2020 before the vaccination era.

METHODS

We surveyed SARS-CoV-2 infection among the HCWs in a hospital through screening for antibody levels and the detection of viral RNA by RT-PCR between May 2020 and December 2020. Occupational and non-occupational potential predictors of disease were surveyed for the HCWs included in this study.

RESULTS

Among 1925 personnel in the hospital, 1732 were included to the study with a response rate of 90%. The overall infection rate of HCWs was 16.3% at the end of 2020, before vaccinations started. In the multivariate analysis, being janitorial staff (OR: 2.24, CI: 1.21-4.14, p = 0.011), being a medical secretary (OR: 4.17, CI: 2.12-8.18, p < 0.001), having at least one household member with a COVID-19 diagnosis (OR: 8.98, CI: 6.64-12.15, p < 0.001), and number of household members > 3 (OR: 1.67, CI: 1.26-2.22, p < 0.001) were found to be significantly associated with SARS-CoV-2 infection.

CONCLUSIONS

Medical secretaries and janitorial staff were under increased risk of SARS-CoV-2 infection. The community-hospital gradient can explain the mode of transmission for infection among HCWs. In the setting of this study, community measures were less strict, whereas hospital infection control was adequate and provided necessary personal protective equipment. Increasing risk in larger households and households with diagnosed COVID-19 patient indicates the community-acquired transmission of the infection.