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1.
Vaccines ; 10(4), 2022.
Article in English | EMBASE | ID: covidwho-1822475

ABSTRACT

Background: Longitudinal surveys to monitor the seroprevalence are required to support efforts for assessment of the levels of endemic stability in certain countries. We investigated seroprevalence of anti-SARS-CoV-2-S1 receptor-binding domain (RBD)-specific antibodies in the serum samples in 2011–2021, including a cohort study of 2019–2021, to evaluate the vaccination and anti-IgG-SARS-CoV-2–S1 RBD-positive statuses to assess the resistance and severity of COVID-19. Materials and Methods: Anti-SARS-CoV-2-S1 RBD-specific antibodies were assayed in the serum samples (N = 565) randomly selected from various cohorts previously recruited from 2011 to 2021 from the city of Moscow and Moscow Region. Among them there were the participants (N = 310) recruited in 2019–2021 with an endpoint of 30 October 2021 when these participants were interviewed over phone with relevant questionnaire. Results: Obtained data indicated a percentage of 3–6% of SARS-CoV-2-S1 RBD-specific antibodies detected in participants recruited in 2011–2019. The percentage of SARS-CoV-2-S1 RBD-specific antibodies was increased to 16.5% in 2020 and to 46% in 2021. The vaccination rate of 238 respondents of this cohort was 58% from August 2020 to October 2021. In total, 12% of respondents were hospitalized. The morbidity rate in the subgroup of anti-SARS-CoV-2-S1 RBD-positive respondents was 5.4-fold higher than that in the subgroup of vaccinated respondents. Conclusions: A small percentage of SARS-CoV-2-S1 RBD-specific antibodies detected in 2011–2019 indicated possible spreading of coronaviruses during the pre-pandemic period. Collective immunity in Moscow and the Moscow region was able to reach 69% from August 2020 to October 2021 if this rate is added to the rate of not vaccinated SARS-CoV-2-S1 RBD-positive subjects.

2.
Clinical Rheumatology ; 2022.
Article in English | EMBASE | ID: covidwho-1820937

ABSTRACT

SARS-CoV-2 infections in children are frequently asymptomatic or mild and can go unnoticed. This study aimed to describe the seroprevalence and clinical course of SARS-CoV-2 in a cohort of children with rheumatic diseases in a real-life setting and assess possible risk factors. A cross-sectional study was performed in a paediatric rheumatology unit (September 2020 to February 2021). At inclusion, a specific questionnaire was completed and SARS-CoV-2 serology was performed. Demographics, treatment and disease activity of patients with and without laboratory-confirmed SARS-CoV-2 infection were compared. A total of 105 children were included. SARS-CoV-2 infection was demonstrated in 27 patients (25.7%). The mean age was 11.8 years, and most patients were females (72.4%). The most frequent underlying condition was juvenile idiopathic arthritis (70.3%;19/27). Patients received immunosuppressive treatment in 78% of cases (21/27). Overall, 44.4% (12/27) of infected patients were asymptomatic. A total of 66.7% (18/27) of patients did not require medical assistance. Three patients required hospital admission because of COVID-19. Children with confirmed SARS-CoV-2 infection were less frequently in remission (52% vs 72%;p 0.014). Moderate disease activity and treatment with oral corticosteroids were associated with higher risk for SARS-CoV-2 (OR 5.05;CI 95%: 1.56–16.3 and OR 4.2;CI 95%: 1.26–13.9, respectively). In a cohort of Spanish paediatric patients with rheumatic diseases, clinical course of COVID-19 was mild, with more than one third of asymptomatic cases. Higher disease activity and oral corticosteroids appear to be risk factors for SARS-CoV-2 infection.Key Points• We aimed to investigate the seroprevalence of SARS-CoV-2 infection in a cohort of Spanish paediatric patients with RD, testing both symptomatic and asymptomatic patients. We also compared treatment and disease activity of patients with and without laboratory-confirmed SARS-CoV-2 infection.• In our cohort of 105 paediatric patients with rheumatic diseases, the clinical course of COVID-19 was mild and 44% of cases were asymptomatic. Three cases required hospital admission with no complications. Seroprevalence was 20%.• No association was found between disease activity or treatment with corticosteroids and symptomatic or asymptomatic infection. Higher disease activity and treatment with oral corticosteroids appeared to be risk factors for laboratory-confirmed SARS-CoV-2 infection.

3.
Danish Medical Journal ; 69(5), 2022.
Article in English | EMBASE | ID: covidwho-1820587

ABSTRACT

Introduction. Knowledge of the seroprevalence and duration of antibodies against SARS-CoV-2 was needed in the early phases of the COVID-19 pandemic and is still necessary for policy makers and healthcare professionals. This information allows us to better understand the risk of reinfection in previously infected individuals. Methods. We investigated the prevalence and duration of detectable antibodies against SARS-CoV-2 in sequentially collected samples from 379 healthcare professionals. Results. SARS-CoV-2 seroprevalence at inclusion was 5.3% (95% confidence interval (CI): 3.3-8.0%) and 25% of seropositive participants reverted during follow-up. At the end of follow-up, the calculated probability of having detectable antibodies among former seropositive participants was 72.2% (95% CI: 54.2-96.2%). Conclusion. Antibodies against SARS-CoV-2 were detectable in a subset of infected individuals for a minimum of 39 weeks.

4.
Int J Gen Med ; 14: 7017-7024, 2021.
Article in English | MEDLINE | ID: covidwho-1817651

ABSTRACT

PURPOSE: Seroprevalence against SARS-CoV-2 within university systems is poorly studied, making evidence-based discussions of educational system reopening difficult. Moreover, few studies evaluate how antibodies against SARS-CoV-2 are maintained over time. We assessed serological response against the SARS-CoV-2 virus among our university students and staff. PATIENTS AND METHODS: In this prospective cohort study, seroprevalence was determined in 705 randomly selected volunteers, members of the Faculty of Medicine and Health Sciences of the University of Alcalá, using a chemiluminescent Siemens' SARS-CoV-2 immunoassay for total antibodies. Positive samples were tested for IgG and IgM/IgA using VIRCLIA® MONOTEST (Vircell). A first analysis took place during June 2020, and in those testing positive, a determination of secondary outcomes was performed in November 2020. RESULTS: A total of 130 subjects showed anti-SARS-CoV-2 antibodies (18.5%, 95% CI, 15.8-21.5%). Of these, IgM/IgA was positive in 27 and indeterminate in 19; IgG was positive in 118, indeterminate in 1. After 23 weeks, among 102 volunteers remeasured, IgG became undetectable in 6. Presence of antibodies was associated, in multivariable logistic regression, with exposure to infected patients (31.3%) [OR 1.84, 95% CI, 1.14-2.96; P = 0.012], presence of COVID-19 symptoms (52.4%) [OR 6.88, 95% CI, 4.28-11.06; P < 0.001], and confirmed earlier infection (82.9%) [OR 11.87, 95% CI, 4.26-33.07; P < 0.001]. CONCLUSIONS: The faculty of medicine and health sciences personnel and students of our university showed a high infection rate for SARS-CoV-2 during 2020 associated with providing clinical care to infected patients. This emphasizes the importance of the performance of continuous surveillance methods of the most exposed health personnel, including health science students.

5.
Investigacion Clinica ; 62(Suplemento 2):43-57, 2021.
Article in Spanish | CAB Abstracts | ID: covidwho-1818975

ABSTRACT

In December 2019, the coronavirus disease COVID-19 began in China. Since then, millions of infections and deaths from this cause have been reported worldwide, particularly among health workers who have suffered the harsh onslaught of the pandemic in the context of healthcare systems collapsed by demand. In this sense, the objective of this work was to determine the prevalence, sociodemographic, epidemiological, and clinical characteristics of COVID-19 present in health workers of the "Instituto Aut..nomo Hospital Universitario de Los Andes" in M..rida-Venezuela. An observational, retrospective, single-center, documentary study was carried out, where 297 clinical-epidemiological records corresponding to 285 health workers were analyzed, in a period between March 16 and November 30, 2020. The records were separated into two groups, front-line workers and support workers. The overall positivity of the RT-PCRs performed was 31.6%. The frequency of positive confirmatory results was highest among support workers at 33.9%. Nursing staff had the highest positivity (39.5%). A seroprevalence of 34.3% was found in immunological tests. The prevalence of SARS-CoV-2 infection among health care workers was higher among support workers compared to front-line workers. Therefore, general and work-specific prevention strategies should be strengthened to limit the spread of SARS-CoV-2 among staff to ensure that they perform safely and effectively.

6.
Vaccines ; 10(3), 2022.
Article in English | EMBASE | ID: covidwho-1818224

ABSTRACT

We aimed at evaluating quantitative IgG response to BNT162b2 COVID-19 vaccine among health care workers (HCW), and exploring the role of demographic, clinical, and occupational factors as predictors of IgG levels. On May 2021, among 6687 HCW at the largest tertiary care University-Hospital of Northwestern Italy, at a median of 15 weeks (Interquartile range-IQR 13.6– 16.0) after second-dose, serological response was present in 99.8%. Seropositivity was >97% in all the subgroups, except those self-reporting immunodeficiency (94.9%). Overall, the median serological IgG value was 990 BAU/mL (IQR 551–1870), with most of subjects with previous SARS-CoV-2 infection or with shorter time lapse (2–8 weeks) between vaccination and serology with values in the highest quintile (>2080). At multivariable analysis, significant predictors of lower values were increasing age, male, current smoking, immunodeficiency, recent occupational contacts, and increasing time lapse from vaccination;conversely, previous infection and recent household contacts were significantly associated with higher IgG levels. Subjects with previous infection kept a very high level (around 2000 BAU/mL) up to 120 days. These results, besides supporting a high serological response up to 4–5 months, suggest predictive factors of faster decay of IgG levels that could be useful in tailoring vaccination strategies.

7.
International Journal of Environmental Research and Public Health ; 19(6), 2022.
Article in English | CAB Abstracts | ID: covidwho-1818102

ABSTRACT

Grocery workers were essential to the workforce and exempt from lockdown requirements as per Minnesota Executive Order 20-20. The risk of COVID-19 transmission in grocery settings is not well documented. This study aimed to determine which factors influenced seropositivity among grocery workers. We conducted a cross-sectional study of Minnesota grocery workers aged 18 and older using a convenience sample. Participants were recruited using a flyer disseminated electronically via e-mail, social media, and newspaper advertising. Participants were directed to an electronic survey and were asked to self-collect capillary blood for IgG antibody testing. Data were analyzed using logistic regression and adjusted for urbanicity, which confounded the relationship between number of job responsibilities in a store and seropositivity. Of 861 Minnesota grocery workers surveyed, 706 (82%) were tested as part of this study, of which 56 (7.9%) tested positive for IgG antibodies. Participants aged 65-74 years had the highest percent positivity. Having multiple job responsibilities in a store was significantly associated with seropositivity in our adjusted model (OR: 1.14 95% CI: 1.01-1.27). Workplace factors influenced seropositivity among Minnesota grocery workers. Future research will examine other potential factors (e.g., in-store preventive measures and access to PPE) that may contribute to increased seropositivity.

8.
Clinical Infectious Diseases ; : 9, 2022.
Article in English | Web of Science | ID: covidwho-1816030

ABSTRACT

Background People in prison are at increased risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We examined the seroprevalence of SARS-CoV-2 and associated carceral risk factors among incarcerated adult men in Quebec, Canada. Methods We conducted a cross-sectional seroprevalence study in 2021 across 3 provincial prisons, representing 45% of Quebec's incarcerated male provincial population. The primary outcome was SARS-CoV-2 antibody seropositivity (Roche Elecsys serology test). Participants completed self-administered questionnaires on sociodemographic, clinical, and carceral characteristics. The association of carceral variables with SARS-CoV-2 seropositivity was examined using Poisson regression models with robust standard errors. Crude and adjusted prevalence ratios (aPR) with 95% confidence intervals (95% CIs) were calculated. Results Between 19 January 2021 and 15 September 2021, 246 of 1100 (22%) recruited individuals tested positive across 3 prisons (range, 15%-27%). Seropositivity increased with time spent in prison since March 2020 (aPR, 2.17;95% CI, 1.53-3.07 for "all" vs "little time"), employment during incarceration (aPR, 1.64;95% CI, 1.28-2.11 vs not), shared meal consumption during incarceration ("with cellmates": aPR, 1.46;95% CI, 1.08-1.97 vs "alone";"with sector": aPR, 1.34;95% CI, 1.03-1.74 vs "alone"), and incarceration post-prison outbreak (aPR, 2.32;95% CI, 1.69-3.18 vs "pre-outbreak"). Conclusions The seroprevalence of SARS-CoV-2 among incarcerated individuals was high and varied among prisons. Several carceral factors were associated with seropositivity, underscoring the importance of decarceration and occupational safety measures, individual meal consumption, and enhanced infection prevention and control measures including vaccination during incarceration. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence was high among incarcerated adult men in Quebec, Canada. Several carceral factors were associated with seropositivity, underscoring decarceration and infection prevention and control measures such as vaccination in preventing future SARS-CoV-2 outbreaks.

9.
Enfermedades infecciosas y microbiologia clinica (English ed.) ; 2022.
Article in English | ScienceDirect | ID: covidwho-1814370

ABSTRACT

Introduction As of 30 April 2020, 203.715 SARS-CoV-2 infections had been reported in Spain, 54.486 in Madrid, 21.4% were health care workers. Our objective is to determine seroprevalence of COVID-19 among workers in a monographic pediatric hospital. Methods Between April13th and 30th, 1.523 health workers were recruited to be tested for SARS-CoV-2 serology screening (All Test®) and they answered a questionnaire with demographic, epidemiological and clinical information and previous exposure to COVID-19. Findings One thousand two hundred ninety two (84.8%) were tested. Positive serology (IgM and/or IgG) to SARS-CoV-2 was found in 17.2% (222/1.292), in 15.5% (201/1.292) if only IgG was considered. Median age was 44±13 years, 73% were female. The 33.8% (75/222) were asymptomatic. Eighty one had a previous positive rRT-PCR. The 14% (32/222) referred a family contact. Conclusion Serology prevalence for SARS-CoV-2 in workers of a pediatric hospital was higher than in general population. Many of them had an unnoticed infection. Resumen Introducción A 30 de abril de 2020, se habían notificado 203.715 infecciones SARS-CoV-2 en España, 54.486 en Madrid, y el 21,4% eran trabajadores de la salud. El objetivo del estudio es determinar la prevalencia serológica de infección SARS-CoV-2 en trabajadores de un hospital monográfico pediátrico. Método Del 13 al 30 de abril, 1.523 trabajadores fueron convocados a realizar un test serológico (All Test®) frente a SARS-CoV-2 y respondieron un cuestionario con información demográfica, clínico-epidemiológica y de exposición a COVID-19. Resultados Mil doscientos noventa y dos (84,8%) fueron estudiados. La prevalencia serológica (IgM y/o IgG+) a SARS-CoV-2 fue del 17,2% (222/1.292) y del 15,5% (201/1.292) considerando IgG positiva. La edad media fue 44 ± 13 años, el 73% eran mujeres. El 33,8% (75/222) fueron asintomáticos. Tenían rRT-PCR positiva previa 81. El 14% (32/222) contacto familiar. Conclusión La prevalencia serológica SARS-CoV-2 en los trabajadores de un hospital pediátrico fue mayor que en la población general. Muchos pasaron una infección inadvertida.

10.
Health Rep ; 33(4):24-33, 2022.
Article in English | PubMed | ID: covidwho-1811972

ABSTRACT

BACKGROUND: Certain population groups face a disproportionate burden of exposure to COVID-19. This study examined characteristics of Canadians living in private households in fall 2020 and winter 2021 who had been infected with COVID-19. DATA AND METHODS: With an online questionnaire and an at-home finger-prick blood test, the Canadian COVID-19 Antibody and Health Survey was designed to estimate the seroprevalence of COVID-19 infection among people in private households in Canada. Data were collected from respondents aged 1 or older in the 10 provinces and the three territorial capitals, from November 2020 to April 2021. Descriptive statistics and logistic regression were used to identify characteristics that were associated with being seropositive for a past COVID-19 infection. Gender differences in observed associations were examined. RESULTS: After covariate adjustment, younger age and visible minority status were associated with an increased likelihood of being seropositive for a past COVID-19 infection. For males, having a visible minority status, having less education and living in a multi-unit dwelling increased the likelihood of being seropositive. Females were more likely to have been seropositive if they worked in health care in direct contact with others. INTERPRETATION: As Canada navigates the fifth and possibly a sixth wave of the pandemic, understanding who was more likely to be infected in earlier waves can help ongoing public health efforts to stop the transmission of COVID-19.

11.
Emerg Infect Dis ; 28(5):1026-1030, 2022.
Article in English | PubMed | ID: covidwho-1809291

ABSTRACT

In a cross-sectional survey in Omdurman, Sudan, during March-April 2021, we estimated that 54.6% of the population had detectable severe acute respiratory syndrome coronavirus 2 antibodies. Overall population death rates among those >50 years of age increased 74% over the first coronavirus disease pandemic year.

12.
BMJ Open ; 12(4):e056637, 2022.
Article in English | PubMed | ID: covidwho-1807409

ABSTRACT

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.

13.
Infection ; 2022.
Article in English | PubMed | ID: covidwho-1803195

ABSTRACT

PURPOSE: To quantify the number of SARS-CoV-2 infections in students and teachers in 14 Secondary schools in eastern Saxony, Germany. Seroprevalence of SARS-CoV-2 antibodies in study population. Number of undetected cases. METHODS: Serial seroprevalence study. RESULTS: The role of educational settings in the SARS-CoV-2 Pandemic is still controversial. Seroprevalence increases from 0.8 to 5.9% from October to December when schools remained open and to 12.2% in March/April during a strict lockdown with closed schools. The ratio of undetected to detected cases decreased from 0.76 to 0.44 during the study period. CONCLUSION: During the second and third wave of the pandemic in Germany, students and teachers are not overrepresented in SARS-CoV-2 infections. The percentage of undetected cases is moderate and decreases over time. The risk of contracting SARS-CoV-2 within the household is higher than contracting it in educational settings making school closures rather ineffective in terms of pandemic control measures or individual risk reduction in children and adolescents. TRIAL REGISTRATION: DRKS00022455 (July 23rd, 2020).

14.
Iranian Journal of Microbiology ; 14(2):138-144, 2022.
Article in English | Academic Search Complete | ID: covidwho-1801584

ABSTRACT

Background and Objectives: Health care workers (HCWs) are a high-risk group for acquiring and transmitting severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Aim of the study was the evaluation of sero-prevalence of SARS-CoV-2 in a random sample of HCWs at a large acute care hospital in Iran. Materials and Methods: We collected blood samples of 180 medical staffs from September 22, 2020 to January 26, 2021. The enzyme linked immunosorbent assays (ELISA) tests were used for evaluation of the presence of IgG antibodies. Participants completed a self-report questionnaire, comprising demographics, occupational, the work area, and personal protection data. Results: Of the 180 HCWs who participated in this study, 44 (24.4%) were seropositive for anti-SARS-CoV-2 IgG. The percentage of IgG positivity was higher in males than females (P<0.05). Also, there was statistically significant difference between presence of the antibodies and the occupation, location, and infecting family members with Covid -1 (P<0.05). Other factors did not associate significantly to antibody presence against SARS-CoV-2 (P>0.05). Conclusion: According to this point that the number of COVID-19 cases is still growing rapidly among HCWs. So, the epidemiological estimate of SARS-CoV-2 infection remains a major challenge that is needed to prevent the spread of infection in the hospitals. [ FROM AUTHOR] Copyright of Iranian Journal of Microbiology is the property of Tehran University of Medical Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

15.
SSRN; 2022.
Preprint in English | SSRN | ID: ppcovidwho-333490

ABSTRACT

Introduction: Sero-surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can reveal trends and differences in subgroups and capture undetected or unreported infections that are not included in case-based surveillance systems. Methods: Cross-sectional, convenience samples of remnant sera from clinical laboratories from 51 U.S. jurisdictions were assayed for infection-induced SARS-CoV-2 antibodies biweekly from October 25, 2020, to July 11, 2021, and monthly from September 6, 2021, to February 26, 2022. Test results were analyzed for trends in infection-induced, nucleocapsid-protein seroprevalence using mixed effects models that adjusted for demographic variables and assay type. Findings: Analyses of 1,469,792 serum specimens revealed U.S. infection-induced SARS-CoV-2 seroprevalence increased from 8.0% (95% confidence interval (CI): 7.9%-8.1%) in November 2020 to 58.2% (CI: 57.4%-58.9%) in February 2022. The U.S. ratio of estimated infections to reported cases was 2.8 (CI: 2.8-2.9) during winter 2020-2021, 2.3 (CI: 2.0-2.5) during summer 2021, and 3.1 (CI: 3.0-3.3) during winter 2021-2022. Infection to reported case ratios ranged from 2.6 (CI: 2.3-2.8) to 3.5 (CI: 3.3-3.7) by region in winter 2021-2022. Interpretation: Infection to reported case ratios suggest a high proportion of infections are not detected by case-based surveillance during periods of increased transmission. The largest increases in seroprevalence-defined infection to reported case ratios coincided with the spread of the B.1.1.529 (Omicron) variant and with increased accessibility of home testing. Infection to reported case ratios varied by region and season with the highest ratios in the midwestern and southern United States during winter 2021-2022. Our results demonstrate that reported case counts did not fully capture differing underlying infection rates and demonstrate the value of sero-surveillance in understanding the full burden of infection. Levels of infection-induced antibody seroprevalence, particularly spikes during periods of increased transmission, are important to contextualize vaccine effectiveness data as the susceptibility to infection of the U.S. population changes.

16.
Journal of Emergency Nursing ; 2022.
Article in English | ScienceDirect | ID: covidwho-1799851

ABSTRACT

Objective Emergency department (ED) healthcare professionals (HCP) are at the frontline of evaluation and management of patients with acute, and often undifferentiated, illness. During the initial phase of the SARS-CoV-2 outbreak, there were concerns that ED HCPs may have been at increased risk of exposure to SARS-CoV-2 due to difficulty in early identification and isolation of patients. This study assessed the seroprevalence of SARS-CoV-2 antibodies among ED HCPs including attending physicians, residents, advanced practice providers, and nurses without prior confirmed history of COVID-19 infection at a quaternary academic medical center. Methods This study was a prospective, cross-sectional study. An ED healthcare professional was deemed eligible if they had worked at least four shifts in the adult ED from April 1, 2020, through May 31, 2020, were asymptomatic on the day of blood draw, and were not known to have had prior documented COVID-19 infection. The study period was December 17, 2020, to January 27, 2021. Eligible participants completed a questionnaire and had a blood sample drawn. Samples were run on the Roche Cobas Elecsys Anti-SARS-CoV-2 antibody assay. Results A total of 103 healthcare professionals (16 attending physicians, 4 emergency residents, 16 advanced practice professionals, and 67 full-time emergency nurses) completed the survey and had their blood drawn. While 17 healthcare professionals reported suspecting they had a prior undiagnosed COVID-19 infection, only three (1 attending physician, 1 advanced practice provider, 1 nurse) of the 103 (2.9%, exact 95% Confidence Interval [0.6%, 8.3%]) were seropositive for SARS-CoV-2 antibodies. Conclusion At this quaternary academic medical center among those who volunteered to take an antibody test, there was a low seroprevalence of SARS-CoV-2 antibodies among ED clinicians who were asymptomatic at the time of blood draw and not known to have had prior COVID-19 infection. Despite many unknowns early in the pandemic, the rate of asymptomatic infections appears to be low.

17.
Saudi Journal of Biological Sciences ; : 103282, 2022.
Article in English | ScienceDirect | ID: covidwho-1799721

ABSTRACT

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) emerged in December 2019 and caused a global pandemic of the Coronavirus Disease 2019 (COVID-19). More than 170 million cases have been reported worldwide with mortality rate of 1-3%. The detection of SARS-CoV-2 by molecular testing is limited to acute infections, therefore serological studies provide a better estimation of the virus spread in a population. This study aims to evaluate the seroprevalence of SARS-CoV-2 in the major city of Riyadh, Saudi Arabia during the sharp increase of the pandemic, in June 2020. Serum samples from non-COVID patients (n=432), patients visiting hospitals for other complications and confirmed negative for COVID-19, and healthy blood donors (n=350) were collected and evaluated using an in-house enzyme-linked immunosorbent assay (ELISA). The overall percentage of positive samples was 7.80% in the combined two populations (n=782). The seroprevalence was lower in the blood donors (6%) than non-COVID-19 patients (9.25%), p = 0.0004. This seroprevalence rate is higher than the documented cases, indicating asymptomatic or mild unreported COVID-19 infections in these two populations. This warrants further national sero-surveys and highlights the importance of real-time serological surveillance during pandemics.

18.
Animals ; 12(8), 2022.
Article in English | EMBASE | ID: covidwho-1798911
19.
Int J Gynaecol Obstet ; 2022 Mar 24.
Article in English | MEDLINE | ID: covidwho-1797882

ABSTRACT

OBJECTIVE: Data on the immune response to SARS-CoV-2 during pregnancy are lacking and the potential role and effect of SARS-CoV-2 vaccination in pregnancy is yet to be completely investigated. METHOD: This is a cross-sectional observational study wherein pregnant women were tested for SARS-CoV-2 immunoglobulin M and immunoglobulin G levels, irrespective of their infective status or presence or symptomatology. RESULT: Of the 220 pregnant women tested, 160 (72.7%) were SARS-CoV-2 IgG positive, 37 (16.8%) were SARS-CoV-2 IgM positive and 27 (16.9%) were both IgG and IgM positive. The average antibody titer found was 10.49 BAU/ml (±14.0) and 0.6 (±0.55) for anti-SARS-CoV-2 IgG and IgM non neutralizing antibodies respectively. ROC analysis for SARS-CoV-2 IgG positivity showed a cut-off value of 1.19 with a sensitivity of 99.3% (0.99 AUC, 95% CI) and specificity of 98.3% (0.99 AUC, 95% CI), respectively. Similarly, ROC analysis for SARS-CoV-2 IgM positivity showed a cut-off value of 1 with a sensitivity of 97.3% (0.99 AUC, 95% CI) and specificity of 98.9% (0.99 AUC, 95% CI), respectively. CONCLUSION: First trimester sero-molecular screening suggests a high prevalence of COVID antibodies in the study population of pregnant women in the first trimester, without the patients being symptomatic.

20.
Infect Dis Model ; 7(2): 25-32, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1796731

ABSTRACT

Objectives: Serological surveys were used to infer the infection attack rate in different populations. The sensitivity of the testing assay, Abbott, drops fast over time since infection which makes the serological data difficult to interpret. In this work, we aim to solve this issue. Methods: We collect longitudinal serological data of Abbott to construct a sensitive decay function. We use the reported COVID-19 deaths to infer the infections, and use the decay function to simulate the seroprevalence and match to the reported seroprevalence in 12 Indian cities. Results: Our model simulated seroprevalence matchs the reported seroprevalence in most of the 12 Indian cities. We obtain reasonable infection attack rate and infection fatality rate for most of the 12 Indian cities. Conclusions: Using both reported COVID-19 deaths data and serological survey data, we infer the infection attack rate and infection fatality rate with increased confidence.

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