Corpus overview


Overview

MeSH Disease

Human Phenotype

Transmission

Seroprevalence
    displaying 41 - 50 records in total 170
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    High SARS-CoV-2 seroprevalence SERO in Health Care Workers but relatively low numbers of deaths in urban Malawi

    Authors: Marah Grace Chibwana; Khuzwayo Chidiwa Jere; Jonathan Mandolo; Vincent Katunga-Phiri; Dumizulu Tembo; Ndaona Mitole; Samantha Musasa; Simon Sichone; Agness Lakudzala; Lusako Sibale; Prisca Matambo; Innocent Kadwala; Rachel Louise Byrne; Alice Mbewe; Marc Y.R. Henrion; Ben Morton; Chimota Phiri; Jane Mallewa; Henry C Mwandumba; Emily R Adams; Stephen B Gordon; Kondwani Charles Jambo

    doi:10.1101/2020.07.30.20164970 Date: 2020-08-01 Source: medRxiv

    Background In low-income countries, like Malawi, important public health measures including social distancing or a lockdown, have been challenging to implement owing to socioeconomic constraints, leading to predictions that the COVID-19 pandemic would progress rapidly. However, due to limited capacity to test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection MESHD, there are no reliable estimates of the true burden of infection MESHD and death MESHD. We, therefore, conducted a SARS-CoV-2 serosurvey amongst health care workers (HCW) in Blantyre city to estimate the cumulative incidence of SARS-CoV-2 infection MESHD in urban Malawi. Methods Five hundred otherwise asymptomatic TRANS HCWs were recruited from Blantyre City (Malawi) from 22nd May 2020 to 19th June 2020 and serum samples SERO were collected all participants. A commercial ELISA SERO was used to measure SARS-CoV-2 IgG antibodies SERO in serum SERO. We run local negative samples (2018 - 2019) to verify the specificity of the assay. To estimate the seroprevalence SERO of SARS CoV-2 antibodies SERO, we adjusted the proportion of positive results based on local specificity of the assay. Results Eighty-four participants tested positive for SARS-CoV-2 antibodies SERO. The HCW with a positive SARS-CoV-2 antibody SERO result came from different parts of the city. The adjusted seroprevalence SERO of SARS-CoV-2 antibodies SERO was 12.3% [CI 9.0-15.7]. Using age TRANS-stratified infection MESHD fatality estimates reported from elsewhere, we found that at the observed adjusted seroprevalence SERO, the number of predicted deaths MESHD was 8 times the number of reported deaths MESHD. Conclusion The high seroprevalence SERO of SARS-CoV-2 antibodies SERO among HCW and the discrepancy in the predicted versus reported deaths MESHD, suggests that there was early exposure but slow progression of COVID-19 epidemic in urban Malawi. This highlights the urgent need for development of locally parameterised mathematical models to more accurately predict the trajectory of the epidemic in sub-Saharan Africa for better evidence-based policy decisions and public health response planning.

    Persistence of anti- SARS-CoV-2 antibodies SERO in non-hospitalized COVID-19 convalescent health care workers

    Authors: Margherita Bruni; Valentina Cecatiello; Angelica Diaz-Basabe; Georgia Lattanzi; Erika Mileti; Silvia Monzani; Laura Pirovano; Francesca Rizzelli; Clara Visintin; Giuseppina Bonizzi; Marco Giani; Marialuisa Lavitrano; Silvia Faravelli; Federico Forneris; Flavio Caprioli; Pier Giuseppe Pelicci; Gioacchino Natoli; Sebastiano Pasqualato; Marina Mapelli; Federica Facciotti

    doi:10.1101/2020.07.30.20164368 Date: 2020-08-01 Source: medRxiv

    Background. Coronavirus disease-19 (COVID-19) is a respiratory illness MESHD caused by the Severe Acute Respiratory Syndrome CoronaVirus 2 MESHD (SARS-CoV-2), a novel beta-coronavirus. Although antibody SERO response to SARS-CoV-2 can be detected early during the infection, several outstanding questions remain to be addressed regarding magnitude and persistence of antibody SERO titer against different viral proteins and their correlation with the strength of the immune response, as measured by serum SERO levels of pro-inflammatory mediators. Methods. An ELISA assay SERO has been developed by expressing and purifying the recombinant SARS-CoV-2 Spike Receptor Binding Domain (RBD), Soluble Ectodomain (Spike), and full length nucleocapsid protein (N protein). Sera from healthcare workers affected by non-severe COVID-19 were longitudinally collected over four weeks, and compared to sera from patients hospitalized in Intensive Care Units (ICU) and SARS-CoV-2-negative subjects for the presence of IgM, IgG and IgA antibodies SERO as well as soluble pro-inflammatory mediators in the sera. Results. Specificity and sensitivity SERO of the ELISA assays SERO were high for anti-RBD IgG and IgA (92-97%) and slightly lower for IgM and the Spike and N proteins (70-85%). The ELISA SERO allowed quantification of IgM, IgG and IgA antibody SERO responses against all the viral antigens tested and showed a correlation between magnitude of the antibody SERO response and disease severity. Non-hospitalized subjects showed lower antibody SERO titers and blood SERO pro-inflammatory cytokine profiles as compared to patients in Intensive Care Units (ICU), irrespective of the antibodies tested SERO. Noteworthy, in non-severe COVID-19 infections, antibody SERO titers against RBD and Spike, but not against the N protein, as well as pro-inflammatory cytokines decreased within a month after viral clearance. Conclusions. Rapid decline in antibody SERO titers and in pro-inflammatory cytokines may be a common feature of non-severe SARS-CoV-2 infection MESHD, suggesting that antibody SERO-mediated protection against re-infection with SARS-CoV-2 is of short duration. These results suggest caution in use serological testing SERO to estimate the prevalence SERO of SARS-CoV-2 infection MESHD in the general population.

    Seroprevalence SERO of anti-SARS-CoV-2 IgG antibodies SERO in Kenyan blood SERO donors

    Authors: Sophie Uyoga; Ifedayo M.O. Adetifa; Henry K. Karanja; James Nyagwange; James Tuju; Perpetual Wanjiku; Rashid Aman; Mercy Mwangangi; Patrick Amoth; Kadondi Kasera; Wangari Ng'ang'a; Charles Rombo; Christine K. Yegon; Khamisi Kithi; Elizabeth Odhiambo; Thomas Rotich; Irene Orgut; Sammy Kihara; Mark Otiende; Christian Bottomley; Zonia N. Mupe; Eunice W. Kagucia; Katherine Gallagher; Anthony Etyang; Shirine Voller; John Gitonga; Daisy Mugo; Charles N. Agoti; Edward Otieno; Leonard Ndwiga; Teresa Lambe; Daniel Wright; Edwine Barasa; Benjamin Tsofa; Philip Bejon; Lynette I. Ochola-Oyier; Ambrose Agweyu; J. Anthony G. Scott; George M Warimwe

    doi:10.1101/2020.07.27.20162693 Date: 2020-07-29 Source: medRxiv

    Background There are no data on SARS-CoV-2 seroprevalence SERO in Africa though the COVID-19 epidemic curve and reported mortality differ from patterns seen elsewhere. We estimated the anti- SARS-CoV-2 antibody SERO prevalence SERO among blood SERO donors in Kenya. Methods We measured anti-SARS-CoV-2 spike IgG prevalence SERO by ELISA SERO on residual blood SERO donor samples obtained between April 30 and June 16, 2020. Assay sensitivity SERO and specificity were 83% (95% CI 59, 96%) and 99.0% (95% CI 98.1, 99.5%), respectively. National seroprevalence SERO was estimated using Bayesian multilevel regression and post-stratification to account for non-random sampling with respect to age TRANS, sex and region, adjusted for assay performance SERO. Results Complete data were available for 3098 of 3174 donors, aged TRANS 15-64 years. By comparison with the Kenyan population, the sample over-represented males TRANS (82% versus 49%), adults TRANS aged TRANS 25-34 years (40% versus 27%) and residents of coastal Counties (49% versus 9%). Crude overall seroprevalence SERO was 5.6% (174/3098). Population-weighted, test-adjusted national seroprevalence SERO was 5.2% (95% CI 3.7, 7.1%). Seroprevalence SERO was highest in the 3 largest urban Counties; Mombasa (9.3% [95% CI 6.4, 13.2%)], Nairobi (8.5% [95% CI 4.9, 13.5%]) and Kisumu (6.5% [95% CI 3.3, 11.2%]). Conclusions We estimate that 1 in 20 adults TRANS in Kenya had SARS-CoV-2 antibodies SERO during the study period. By the median date of our survey, only 2093 COVID-19 cases and 71 deaths had been reported through the national screening system. This contrasts, by several orders of magnitude, with the numbers of cases and deaths MESHD reported in parts of Europe and America when seroprevalence SERO was similar.

    Serial population based serosurvey of antibodies to SARS-CoV-2 SERO in a low and high transmission TRANS area of Karachi, Pakistan

    Authors: Muhammad Imran Nisar; Nadia Ansari; Mashal Amin; Farah Khalid; Aneeta Hotwani; Najeeb Rehman; Arjumand Rizvi; Arslan Memon; Zahoor Ahmed; Ashfaque Ahmed; Junaid Iqbal; Ali Faisal Saleem; Uzma Bashir Aamir; Daniel B Larremore; Bailey Fosdick; Fyezah Jehan

    doi:10.1101/2020.07.28.20163451 Date: 2020-07-29 Source: medRxiv

    Background Pakistan is among the first low- and middle-income countries affected by COVID-19 pandemic. Monitoring progress through serial sero-surveys SERO, particularly at household level, in densely populated urban communities can provide insights in areas where testing is non-uniform. Methods Two serial cross-sectional household surveys were performed in April (phase 1) and June (phase 2) 2020 each in a low- (District Malir) and high- transmission TRANS (District East) area of Karachi, Pakistan. Household were selected using simple random sampling (Malir) and systematic random sampling (East). Individual participation rate from consented households was 82.3% (1000/1215 eligible) in phase 1 and 76.5% (1004/1312 eligible) in phase 2. All household members or their legal guardians answered questions related to symptoms of Covid-19 and provided blood SERO for testing with commercial Elecsys Anti-SARS-CoV-2 immunoassay SERO targeting combined IgG and IgM. Seroprevalence SERO estimates were computed for each area and time point independently. Given correlation among household seropositivity values, a Bayesian regression model accounting for household membership, age TRANS and gender TRANS was used to estimate seroprevalence SERO. These estimates by age TRANS and gender TRANS were then post-stratified to adjust for the demographic makeup of the respective district. The household conditional risk of infection TRANS risk of infection TRANS was estimated for each district and its confidence interval were obtained using a non-parametric bootstrap of households. Findings Post-stratified seroprevalence SERO was estimated to be 0.2% (95% CI 0-0.7) in low-and 0.4% (95% CI 0 - 1.3) in high- transmission TRANS areas in phase 1 and 8.7% (95% CI 5.1-13.1) in low- and 15.1% (95% CI 9.4 -21.7) in high- transmission TRANS areas in phase 2, with no consistent patterns between prevalence SERO rates for males TRANS and females TRANS. Conditional risk of infection TRANS risk of infection TRANS infection MESHD estimates (possible only for phase 2) were 0.31 (95% CI 0.16-0.47) in low- and 0.41(95% CI 0.28-0.52) in high- transmission TRANS areas. Of the 166 participants who tested positive, only 9(5.4%) gave a history of any symptoms. Interpretation A large increase in seroprevalence SERO to SARS-CoV-2 infection MESHD is seen, even in areas where transmission TRANS is reported to be low. Mostly the population is still seronegative. A large majority of seropositives do not report any symptoms. The probability that an individual in a household is infected, given that another household member is infected is high in both the areas. These results emphasise the need to enhance surveillance activities of COVID-19 especially in low- transmission TRANS sites and provide insights to risks of household transmission TRANS in tightly knit neighbourhoods in urban LMIC settings.

    Diagnostic accuracy of two commercially available rapid assays for detection of IgG and IgM antibodies SERO to SARS-CoV-2 compared to ELISA SERO in a low- prevalence SERO population

    Authors: Klaus Hackner; Peter Errhalt; Martin Willheim; Maria-Anna Grasl; Jasmina Lagumdzija; Waltraud Riegler; Michael Ecker; Matthias Wechdorn; Florian Thalhammer; Ojan Assadian

    doi:10.21203/rs.3.rs-50887/v1 Date: 2020-07-29 Source: ResearchSquare

    Background: New commercially available point-of-care (POC) immunodiagnostic tests are appearing, which may yield rapid results for anti- SARS-CoV-2 antibodies SERO. The aim of this study was to evaluate the diagnostic accuracy of rapid antibody SERO detection tests compared to a validated laboratory-based enzyme-linked immunosorbent assay SERO ( ELISA SERO) and to investigate infections amongst healthcare workers (HCWs) after unprotected close contact TRANS to COVID-19 patients. Methods: Blood SERO serum SERO and whole blood SERO of 130 participants were tested with NADAL® COVID-19 IgG/IgM Rapid Test SERO and mö-screen 2019-NCOV Corona Virus Test against a validated ELISA SERO test. Infection status was evaluated using real-time polymerase-chain-reaction.Results: Acute COVID-19 infection MESHD was detected in 2.4% of exposed HCWs. Antibody tests SERO showed an overall frequency of IgG and IgM in 5.3%, with 1.6% asymptomatic TRANS infections MESHD. The NADAL® test showed a sensitivity SERO (IgM/ IgG) of 100% (100%/ 100%), a specificity (IgM/ IgG) of 98.8% (97.6%/ 100 %), a PPV of 76.9% (57.1%/ 100%), an NPV of 100% (100%/ 100%), and a diagnostic accuracy of 98.8% (97.7%/ 100%). The mö-screen test had a sensitivity SERO (IgM/IgG) of 90.9% (80%/ 100%), a specificity (IgM/IgG) of 98.8% (97.6%/ 100%), a PPV of 76.9% (57.1%/ 100%), an NPV of 99.6% (99.2%/ 100%), and a diagnostic accuracy of 98.5% (96.9%/ 100%). Conclusions: The frequency of COVID-19 infections MESHD in HCWs after unprotected close contact TRANS is higher than in the general population of a low- prevalence SERO country. Both POC tests SERO were useful for detecting IgG, but did not perform well for IgM, mainly due to false positive results.

    Prevalence SERO of amyloid blood SERO clots in COVID-19 plasma SERO

    Authors: Etheresia Pretorius; Chantelle Venter; Gert J Laubscher; Petrus J Lourens; Janami Steenkamp; Douglas B Kell

    doi:10.1101/2020.07.28.20163543 Date: 2020-07-29 Source: medRxiv

    The rapid detection of COVID-19 uses genotypic testing for the presence of SARS-Cov-2 virus in nasopharyngeal swabs, but it can have a poor sensitivity SERO. A rapid, host-based physiological test that indicated whether the individual was infected MESHD or not would be highly desirable. Coagulaopathies are a common accompaniment to COVID-19, especially micro-clots within the lungs. We show here that microclots can be detected in the native plasma SERO of COVID-19 patient, and in particular that such clots are amyloid in nature as judged by a standard fluorogenic stain. This provides a rapid and convenient test (P<0.0001), and suggests that the early detection and prevention of such clotting could have an important role in therapy.

    Longitudinal COVID-19 Surveillance and Characterization in the Workplace with Public Health and Diagnostic Endpoints

    Authors: Manjula Gunawardana; Jessica Breslin; John M Cortez; Sofia Rivera; Simon Webster; F Javier Ibarrondo; Otto O Yang; Richard B Pyles; Christina M Ramirez; Amy P Adler; Peter A Anton; Marc M Baum

    doi:10.1101/2020.07.25.20160812 Date: 2020-07-28 Source: medRxiv

    Background The rapid spread of severe acute respiratory syndrome coronavirus 2 MESHD (SARS-CoV-2) and the associated coronavirus disease MESHD 2019 (COVID-19) have precipitated a global pandemic heavily challenging our social behavior, economy, and healthcare infrastructure. Public health practices currently represent the primary interventions for managing the spread of the pandemic. We hypothesized that frequent, longitudinal workplace disease MESHD surveillance would represent an effective approach to controlling SARS-CoV-2 transmission TRANS among employees and their household members, reducing potential economic consequences and loss of productivity of standard isolation methods, while providing new insights into viral-host dynamics. Methodology and Findings On March 23, 2020 a clinical study (OCIS-05) was initiated at a small Southern California organization. Results from the first 3 months of the ongoing study are presented here. Study participants (27 employees and 27 household members) consented to provide frequent nasal or oral swab samples that were analyzed by RT-qPCR for SARS-CoV-2 RNA using CDC protocols. Only participants testing negative were allowed to enter the "safe zone" workplace facility. Optional blood SERO samples were collected at baseline and throughout the 3-month study. Serum SERO virus-specific antibody SERO concentrations (IgG, IgM, and IgA) were measured using a selective, sensitive, and quantitative ELISA assay SERO developed in house. A COVID-19 infection MESHD model, based on traditional SEIR compartmental models combined with Bayesian non-linear mixed models and modern machine learning, was used to predict the number of employees and household members who would have become infected in the absence of workplace surveillance. Two study participants were found to be infected by SARS-CoV-2 during the study. One subject, a household member, tested positive clinically by RT-qPCR prior to enrollment and experienced typical COVID-19 symptoms that did not require hospitalization. While on study, the participant was SARS-CoV-2 RNA positive for at least 71 days and had elevated virus-specific antibody SERO concentrations (medians: IgM, 9.83 ug mL-1; IgG, 11.5 ug mL-1; IgA, 1.29 ug mL-1) in serum samples SERO collected at three timepoints. A single, unrelated employee became positive for SARS-CoV-2 RNA over the course of the study, but remained asymptomatic TRANS with low associated viral RNA copy numbers. The participant did not have detectable serum SERO IgM and IgG concentrations, and IgA concentrations decayed rapidly (half-life: 1.3 d). The employee was not allowed entry to the safe zone workplace until testing negative three consecutive times over 7 d. No other employees or household members contracted COVID-19 over the course of the study. Our model predicted that under the current prevalence SERO in Los Angeles County without surveillance intervention, up to 7 employees (95% CI = 3-10) would have become infected with at most 1 of them requiring hospitalizations and 0 deaths. Conclusions Our clinical study met its primary objectives by using intense longitudinal testing to provide a safe work environment during the COVID-19 pandemic, and elucidating SARS-CoV-2 dynamics in recovering and asymptomatic TRANS participants. The surveillance plan outlined here is scalable and transferrable. The study represents a powerful example on how an innovative public health initiative can be dovetailed with scientific discovery.

    Low Seroprevalence SERO of SARS-CoV-2 in Rhode Island Blood SERO Donors Determined using Multiple Serological Assay SERO Formats

    Authors: Daniel J Nesbitt; Daniel Jin; Joseph W Hogan; Philip A Chan; Melissa J Simon; Matthew Vargas; Ewa King; Richard C Huard; Utpala Bandy; Christopher D Hillyer; Larry L Luchsinger

    doi:10.1101/2020.07.20.20157743 Date: 2020-07-26 Source: medRxiv

    Epidemic projections and public health policies addressing Coronavirus disease MESHD ( COVID MESHD)-19 have been implemented without data reporting on the seroconversion of the population since scalable antibody testing SERO has only recently become available. We measured the percentage of severe acute respiratory syndrome MESHD- Coronavirus-2 (SARS-CoV-2) seropositive individuals from 2,008 blood SERO donors drawn in the state of Rhode Island (RI). We utilized multiple antibody testing SERO platforms, including lateral flow immunoassays SERO (LFAs), enzyme-linked immunosorbent assays SERO ( ELISAs SERO) and high throughput serological assays SERO (HTSAs). We report than an estimated seropositive rate of RI blood SERO donors of approximately 0.6% existed in April-May of 2020. These data imply that seroconversion, and thus infection MESHD, is likely not widespread within this population. Daily new case rates peaked in RI in late April 2020. We conclude that IgG LFAs and HTSAs are suitable to conduct seroprevalence SERO assays in random populations. More studies will be needed using validated serological tests SERO to improve the precision and report the kinetic progression of seroprevalence SERO estimates.

    Covid-19 serology in nephrology health care workers

    Authors: Thomas Reiter; Sahra Pajenda; Ludwig Wagner; Martina Gaggl; Johanna Atamaniuk; Barbara Holzer; Irene Zimpernik; Daniela Gerges; Katharina Mayer; Christof Aigner; Robert Strassl; Sonja Jansen-Skoupy; Manuela Födinger; Gere Sunder-Plassmann; Alice Schmidt

    doi:10.1101/2020.07.21.20136218 Date: 2020-07-26 Source: medRxiv

    Background: Chronic kidney disease HP Chronic kidney disease MESHD patients show a high mortality in case of a SARS-CoV-2 infection MESHD. Thus, to be informed on Nephrology personnel's sero-status might be crucial for patient protection. However, limited information exists about the presence of SARS-CoV-2 antibodies SERO in asymptomatic TRANS individuals. Methods: We examined the seroprevalence SERO of SARS-CoV-2 IgG and IgM antibodies SERO among health care workers of a tertiary care kidney center during the peak phase of the Covid-19 crisis in Austria using an orthogonal test strategy and a total of 12 commercial nucleocapsid protein or spike glycoprotein based assays as well as Western blotting and a neutralization assay. Results: At baseline 60 of 235 study participants (25.5%, 95% CI: 20.4-31.5) were judged to be borderline positive or positive for IgM or IgG using a high sensitivity SERO/low specificity threshold in one test system. Follow-up analysis after about two weeks revealed IgG positivity in 12 (5.1%, 95% CI: 2.9-8.8) and IgM positivity in six (2.6%, 95% CI: 1.1-5.6) in at least one assay. 2.1% (95% CI: 0.8-5.0) of health care workers showed IgG nucleocapsid antibodies SERO in at least two assays. By contrast, positive controls with proven Covid-19 showed antibody SERO positivity among almost all test systems. Moreover, serum samples SERO obtained from health care workers did not show SARS-CoV-2 neutralizing capacity, in contrast to positive controls. Conclusions: Using a broad spectrum of antibody tests SERO the present study revealed inconsistent results for SARS-CoV-2 seroprevalence SERO among asymptomatic TRANS individuals, while this was not the case among Covid-19 patients.

    SARS-CoV-2 antibody SERO prevalence SERO in health care workers: Preliminary report of a single center study

    Authors: Michael Brant-Zawadzki; Deborah Fridman; Philip Robinson; Matthew Zahn; Randy German; Marcus Breit; Junko Hara

    doi:10.1101/2020.07.20.20158329 Date: 2020-07-25 Source: medRxiv

    SARS-CoV-2 has driven a pandemic crisis. Serological surveys have been conducted to establish prevalence SERO for covid-19 antibody SERO in various cohorts and communities. However, the prevalence SERO among healthcare workers is still being analyzed. The present study reports on initial sero-surveillance conducted on healthcare workers at a regional hospital system in Orange County, California, during May and June, 2020. Study participants were recruited from the entire hospital employee workforce and the independent medical staff. Data were collected for job title, location, covid-19 symptoms, a PCR test history, travel TRANS record since January 2020, and existence of household contacts TRANS with covid-19. A blood SERO sample was collected from each subject for serum SERO analysis for IgG antibodies SERO to SARS-CoV-2. Of 3,013 tested individuals, a total 2,932 were included in the analysis due to some missing data. Observed prevalence SERO of 1.06% (31 antibody SERO positive cases), adjusted prevalence SERO of 1.13% for test sensitivity SERO and specificity were identified. Significant group differences between positive vs. negative were observed for age TRANS (z = 2.65, p = .008), race (p = .037), presence of fever HP fever MESHD (p < .001) and loss of smell (p < .001). Possible explanation for this low prevalence SERO includes a relatively low local geographic community prevalence SERO (~4.4%) at the time of testing, the hospital's timely procurement of personal protective equipment, rigorous employee education MESHD, patient triage and treatment protocol development and implementation. In addition, possible greater presence of cross-reactive adaptive T cell mediated immunity in healthcare workers vs. the general population may have contributed. Determining antibody SERO prevalence SERO in front-line workers, and duration of antibody SERO presence may help stratify the workforce for risk, establish better health place policies and procedures, and potentially better mitigate transmission TRANS.

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MeSH Disease
Human Phenotype
Transmission
Seroprevalence


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