SARS-CoV-2 antibody seroprevalence in Lebanon: findings from the first nationwide serosurvey

Abstract Background Lebanon, a small country in the Middle East, remains severely affected by the COVID-19 pandemic. Seroprevalence surveys of anti-SARS-CoV-2 antibodies provide accurate estimates of SARS-CoV-2 infection and hence evaluate the extent of the pandemic. The present study aimed to evaluate the prevalence of SARS-CoV-2 antibodies in Lebanon and to compare the estimated cumulative number of COVID-19 cases with the officially registered number of laboratory-confirmed cases up to January 15, 2021. Methods A nationwide population-based serosurvey study was conducted in Lebanon between December 7, 2020, and January 15, 2021, before the initiation of the national vaccination program. The nCOVID-19 IgG & IgM point-of-care (POCT) rapid test was used to detect the presence of anti-SARS-COV-2 immunoglobulin G (IgG) in the blood. Seroprevalence was estimated after weighting for sex, age, and area of residence and adjusting for the test performance. Results Of the 2058 participants, 329 were positive for IgG SARS-COV-2, resulting in a crude seroprevalence of 16.0% (95% CI 14.4–17.6). The weighed seroprevalence was 15.9% (95% CI of 14.4 and 17.4). After adjusting for test performance, the population weight-adjusted seroprevalence was 18.5% (95% CI 16.8–20.2). This estimate implies that 895,770 individuals of the general population were previously infected by COVID-19 up to January 15, 2021 in Lebanon. The overall estimated number of subjects with previous SARS-CoV-2 infection was three times higher than the officially reported cumulative number of confirmed cases. Seroprevalence was similar across age groups and sexes (p-value > 0.05). However, significant differences were revealed across governorates. Conclusions Our results suggest that the Lebanese population is still susceptible to SARS-CoV-2 infection and far from achieving herd immunity. These findings represent an important contribution to the surveillance of the COVID-19 pandemic in Lebanon and to the understanding of how this virus spreads. Continued surveillance for COVID-19 cases and maintaining effective preventive measures are recommended to control the epidemic spread in conjunction with a national vaccination campaign to achieve the desired level of herd immunity against COVID-19.

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Seroprevalence of anti-SARS-CoV-2 antibodies in Iquitos, Loreto, Peru

10.1101/2021.01.17.21249913 ◽

2021 ◽

Author(s):

Carlos Álvarez-Antonio ◽

Graciela Meza-Sánchez ◽

Carlos Calampa ◽

Wilma Casanova ◽

Cristiam Carey ◽

...

Keyword(s):

Test Performance ◽

Herd Immunity ◽

Age Groups ◽

Rapid Test ◽

Prevalence Ratio ◽

Population Based ◽

Current Data ◽

Survey Analysis ◽

Population Based Study

SummaryBackgroundDetection of SARS-CoV-2 antibodies among people at risk is critical for understanding both the prior transmission of COVID-19 and vulnerability of the population to the continuing transmission and, when done serially, the intensity of ongoing transmission over an interval in a community. In this study, we estimated the seroprevalence of COVID-19 in a representative population-based cohort of Iquitos, one of the regions with the highest mortality rates from COVID-19 in Peru, where a devastating number of cases occurred in March 2020.MethodsWe conducted a population-based study of transmission tested each participant using the COVID-19 IgG/IgM Rapid Test from Orient Gene Biotech and used survey analysis methods to estimate seroprevalence accounting for the sampling design effect and test performance characteristics. Here we report results from the baseline (13 to 18 July 2020) and the first month of follow-up (13 to 18 August 2020) study.FindingsWe enrolled a total of 716 participants and estimated seroprevalence of 70.0% (95% CI: 67.0%–73.4%), a test-re-test positivity of 65% (95% CI: 61.0%–68.3%), and an incidence of new exposures of 1.8% (95% CI: 0.9%–3.2%) data that suggest that transmission is ongoing but is occurring at low levels. We observed significant differences in the seroprevalence between age groups, with participants 18 to 29 years of age having lower seroprevalence than children <12 years of age (Prevalence ratio =0.85 [PR]; 95% CI: 0.73 – 0.98), suggesting that children were not refractory to infection in this setting.InterpretationIquitos demonstrates one of the highest rates of seroprevalence of COVID-19 worldwide. Current data shows a limited case burden in Iquitos for the past seven months and suggests that these levels are sufficient to provide significant but incomplete herd immunity.FundingDirección Regional de Salud de Loreto, DIRESA, Loreto, Peru

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Seroprevalence of COVID-19 virus infection in Guilan province, Iran

10.1101/2020.04.26.20079244 ◽

2020 ◽

Cited By ~ 28

Author(s):

Maryam Shakiba ◽

Seyed Saeed Hashemi Nazari ◽

Fardin Mehrabian ◽

Seyed Mahmoud Rezvani ◽

Zahra Ghasempour ◽

...

Keyword(s):

Virus Infection ◽

Test Performance ◽

Care Center ◽

Rapid Test ◽

Population Based ◽

Asymptomatic Infection ◽

Phone Call ◽

Infected People ◽

Health Care Center ◽

Population Weight

AbstractBackgroundThe extent of infection by coronavirus disease 2019 has not been well known. In this study we aimed to determine seropositivity of COVID-19 virus infection in population of a highly affected area in north of Iran.MethodsIn a population-based cluster random sampling design through phone call invitation, a total of 196 household including 551 subjects agreed to participate in this study. Each participant were taken 50ml blood sample at health care center. Rapid test kits were used to detect antibody against COVID-19. Crude, population-weight adjusted and test performance adjusted prevalence of antibody seropositivity to SARS-CoV-2 were reported.ResultsThe prevalence of antibody seropositivity was 22% (95%CI: 19-26%). The population weight adjusted estimate was 21% (95%CI: 14-29%) and test performance adjusted prevalence was 33% (95%CI: 28-39%). Based on these estimates the range of infected people in this province would be between 518000 and 777000.ConclusionThe population seropositivity prevalence of COVID-19 virus infection indicated that the asymptomatic infection is much higher than the number of confirmed cases of COVID-19. This estimate can be used to better detect infection fatality rate and decide for public policy guidelines.

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Screening for SARS-CoV-2 infection in asymptomatic individuals using the Panbio™ COVID-19 Antigen Rapid Test (Abbott) compared to RT-qPCR

10.1101/2020.12.03.20243311 ◽

2020 ◽

Author(s):

Beatrice M.F. Winkel ◽

Emma Schram ◽

Hendrik Gremmels ◽

Sylvia B. Debast ◽

Rob Schuurman ◽

...

Keyword(s):

Test Performance ◽

Point Of Care ◽

Rapid Test ◽

High Specificity ◽

Population Based ◽

Sensitivity Analyses ◽

Staff Members ◽

Subsequent Test ◽

Asymptomatic Individuals ◽

Asymptomatic Subjects

AbstractBackgroundAntigen-based point of care tests for identification of SARS-CoV-2 may markedly enhance effectiveness of population-based controlling strategies. Previous studies have demonstrated acceptable sensitivity and high specificity compared to RT-qPCR in symptomatic individuals, but test performance for asymptomatic individuals is unknown.MethodsTest performance of the Panbio™ COVID-19 Ag Rapid Test (Abbott) was compared to RT-qPCR in a longitudinal cohort study of asymptomatic football players and staff members of professional football clubs. Based on timing of symptoms and prior and subsequent test results, positive RT-qPCR tests were categorized as pre-symptomatic, early or late infection or persistent RNA shedding.Findings2425 tests were performed in 824 individuals, of which 52 (6.3%) were SARS-CoV-2 positive based on RT-qPCR. There were 2406 paired sets from asymptomatic subjects for analysis. Sixteen Panbio™ tests were inconclusive, for which sensitivity analyses were performed (considering results as either positive or negative or being excluded). Sensitivity of Panbio™ ranged from 61.76% (95% CI 49.2-73.3) to 69.12% (95% CI: 56.7-79.8) and specificity from 99.53% (95% CI: 99.2-99.8) to 100% (95% CI: 99.8-100). Sensitivity of Panbio™ to detect subjects with pre-symptomatic/early infection (n= 42) ranged from 81.82% (95% CI: 67.3-91.8) to 90.91% (95% CI: 78.3-97.5) with specificity always above 99%.InterpretationIn asymptomatic subjects the Panbio™ COVID-19 Ag Rapid Test had sensitivity of 81.82% to 90.91% and specificity above 99% for identifying pre-symptomatic and early SARS-CoV-2 infection.FundingThis study was funded by the executing institutes. The Panbio™ COVID-19 Ag Rapid Tests were provided by the Ministry of Health, Welfare and Sport (VWS).

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Screening for SARS-CoV-2 infection in asymptomatic individuals using the Panbio COVID-19 antigen rapid test (Abbott) compared with RT-PCR: a prospective cohort study

BMJ Open ◽

10.1136/bmjopen-2020-048206 ◽

2021 ◽

Vol 11 (10) ◽

pp. e048206

Author(s):

Beatrice Winkel ◽

Emma Schram ◽

Hendrik Gremmels ◽

Sylvia Debast ◽

Rob Schuurman ◽

...

Keyword(s):

Cohort Study ◽

Test Performance ◽

Point Of Care ◽

Rapid Test ◽

High Specificity ◽

Population Based ◽

Sensitivity Analyses ◽

Rt Pcr ◽

Subsequent Test ◽

Asymptomatic Individuals

BackgroundAntigen-based point-of-care tests for identification of SARS-CoV-2 may markedly enhance effectiveness of population-based controlling strategies. Previous studies have demonstrated >70% sensitivity and high specificity compared with reverse transcriptase real-time PCR (RT-PCR) in symptomatic individuals, but test performance for asymptomatic individuals is unknown.MethodsTest performance of the Panbio COVID-19 Ag Rapid Test (Abbott) was compared with RT-PCR in a longitudinal cohort study of asymptomatic football players and staff members of professional football clubs. Based on timing of symptoms and prior and subsequent test results, positive RT-PCR tests were categorised as presymptomatic, early or late infection, or persistent RNA shedding.Findings2425 tests were performed in 824 individuals, of which 52 (6.3%) were SARS-CoV-2 positive based on RT-PCR. There were 2406 paired sets from asymptomatic subjects for analysis. Sixteen Panbio tests were inconclusive, for which sensitivity analyses were performed (considering results as either positive or negative or being excluded). Sensitivity of Panbio for screening of asymptomatic individuals ranged from 80.0% (61.4–92.3) to 86.67% (69.2–96.2) and specificity from 99.53% (95% CI 99.2 to 99.8) to 100% (95% CI 99.8 to 100). Sensitivity of Panbio to detect subjects with presymptomatic/early infection (n=42) ranged from 81.82% (95% CI 67.3 to 91.8) to 90.91% (95% CI 78.3 to 97.5) with specificity always above 99%.InterpretationThe Panbio COVID-19 Ag rapid test identifies 81%–90% of presymptomatic and early asymptomatic SARS-CoV-2 infections with high specificity. This test may therefore be adopted in testing strategies such as targeted screening of specific populations where prevalence is low.

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Comparison of Four Commercially Available Point-of-Care Tests to Detect Antibodies against Canine Parvovirus in Dogs

Viruses ◽

10.3390/v13010018 ◽

2020 ◽

Vol 13 (1) ◽

pp. 18

Author(s):

Michèle Bergmann ◽

Mike Holzheu ◽

Yury Zablotski ◽

Stephanie Speck ◽

Uwe Truyen ◽

...

Keyword(s):

Test Performance ◽

Point Of Care ◽

Reference Method ◽

Canine Parvovirus ◽

P Value ◽

Important Indicator ◽

Specificity And Sensitivity ◽

Specific Pathogen ◽

The One ◽

Point Of Care Tests

Measuring antibodies to evaluate dogs´ immunity against canine parvovirus (CPV) is useful to avoid unnecessary re-vaccinations. The study aimed to evaluate the quality and practicability of four point-of-care (POC) tests for detection of anti-CPV antibodies. The sera of 198 client-owned and 43 specific pathogen-free (SPF) dogs were included; virus neutralization was the reference method. Specificity, sensitivity, positive and negative predictive value (PPV and NPV), and overall accuracy (OA) were calculated. Specificity was considered to be the most important indicator for POC test performance. Differences between specificity and sensitivity of POC tests in the sera of all dogs were determined by McNemar, agreement by Cohen´s kappa. Prevalence of anti-CPV antibodies in all dogs was 80% (192/241); in the subgroup of client-owned dogs, it was 97% (192/198); and in the subgroup of SPF dogs, it was 0% (0/43). FASTest® and CanTiCheck® were easiest to perform. Specificity was highest in the CanTiCheck® (overall dogs, 98%; client-owned dogs, 83%; SPF dogs, 100%) and the TiterCHEK® (overall dogs, 96%; client-owned dogs, 67%; SPF dogs, 100%); no significant differences in specificity were observed between the ImmunoComb®, the TiterCHEK®, and the CanTiCheck®. Sensitivity was highest in the FASTest® (overall dogs, 95%; client-owned dogs, 95%) and the CanTiCheck® (overall dogs, 80%; client-owned dogs, 80%); sensitivity of the FASTest® was significantly higher compared to the one of the other three tests (McNemars p-value in each comparison: <0.001). CanTiCheck® would be the POC test of choice when considering specificity and practicability. However, differences in the number of false positive results between CanTiCheck®, TiterCHEK®, and ImmunoComb® were minimal.

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Healthy aging profile in octogenarians in Brazil

Revista Latino-Americana de Enfermagem ◽

10.1590/1518-8345.0694.2724 ◽

2016 ◽

Vol 24 (0) ◽

Cited By ~ 3

Author(s):

Ana Cristina Viana Campos ◽

Efigênia Ferreira e Ferreira ◽

Andréa Maria Duarte Vargas ◽

Lúcia Hisako Takase Gonçalves

Keyword(s):

Older Adults ◽

Decision Tree ◽

Healthy Aging ◽

Age Groups ◽

Population Based ◽

P Value ◽

Age Group ◽

Monthly Income ◽

Tree Model ◽

Socioeconomic Characteristics

ABSTRACT Objective: to identify the healthy aging profile in octogenarians in Brazil. Method: this population-based epidemiological study was conducted using household interviews of 335 octogenarians in a Brazilian municipality. The decision-tree model was used to assess the healthy aging profile in relation to the socioeconomic characteristics evaluated at baseline. All of the tests used a p-value < 0.05. Results: the majority of the 335 participating older adults were women (62.1%), were aged between 80 and 84 years (50.4%), were widowed (53.4%), were illiterate (59.1%), had a monthly income of less than one minimum wage (59.1%), were retired (85.7%), lived with their spouse (63.8%), did not have a caregiver (60.3%), had two or more children (82.7%), and had two or more grandchildren (78.8%). The results indicate three age groups with a healthier aging profile: older adults aged 80 to 84 years (55.6%), older adults aged 85 years and older who are married (64.9%), and older adults aged 85 and older who do not have a partner or a caregiver (54.2%). Conclusion: the healthy aging profile of octogenarians can be explained by age group, marital status, and the presence of a caregiver.

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Point-of-care serological assays for SARS-CoV-2 in a UK hospital population: potential for enhanced case finding

10.21203/rs.3.pex-930/v1 ◽

2020 ◽

Author(s):

Scott Pallett ◽

Aatish Patel ◽

Gary Davies ◽

Luke Moore

Keyword(s):

Test Performance ◽

Serological Test ◽

Point Of Care ◽

Rapid Test ◽

Antibody Test ◽

Preliminary Evaluation ◽

Hospital Inpatient ◽

Case Identification ◽

Global Pandemic ◽

Population Potential

Abstract Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic, causing over 3,600,000 reported cases and 250,000 deaths worldwide.1 Case identification has predominantly been made by real-time polymerase chain reaction (PCR) during the acute phase and largely restricted to healthcare laboratories. Serological assays are emerging but independent validation is urgently required to assess their utility. Where a plurality of point-of-care (POC) SARS-CoV-2 antibody test kits have become available, we will therefore aim to evaluate a range of kits against the current available gold-standard diagnostic test of PCR in an initial, exploratory study. We will then proceed to carry out testing with 200 hospital inpatients using the OrientGene COVID-19 IgG/IgM Rapid Test Cassette against PCR in order to undergo a preliminary evaluation of POC serological test performance characteristics within a hospital inpatient cohort.

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Seroprevalence of anti-SARS-CoV-2 antibodies six months into the vaccination campaign in Geneva, Switzerland

10.1101/2021.08.12.21261929 ◽

2021 ◽

Author(s):

Silvia Stringhini ◽

María-Eugenia Zaballa ◽

Nick Pullen ◽

Javier Perez-Saez ◽

Carlos de Mestral ◽

...

Keyword(s):

Vaccination Campaign ◽

Age Groups ◽

Credible Interval ◽

Population Based ◽

Vaccine Hesitancy ◽

Socioeconomically Disadvantaged ◽

Cross Sectional ◽

Vaccination Rates ◽

Health Measures ◽

Random Samples

Background: Up-to-date seroprevalence estimates are critical to describe the SARS-CoV-2 immune landscape in the population and guide public health measures. We aimed to estimate the seroprevalence of anti-SARS-CoV-2 antibodies 15 months into the COVID-19 pandemic and six months into the vaccination campaign. Methods: We conducted a population-based cross-sectional serosurvey between June 1 and July 7, 2021, recruiting participants from age- and sex-stratified random samples of the general population. We tested participants for anti-SARS-CoV-2 antibodies targeting the spike (S) or nucleocapsid (N) proteins (Roche Elecsys immunoassays). We estimated the anti-SARS-CoV-2 antibodies seroprevalence following vaccination and/or infection (anti-S antibodies), or infection only (anti-N antibodies). Results: We included 3355 individuals, of which 1814 (54.1%) were women, 697 (20.8%) were aged <18 years and 449 (13.4%) were aged ≥65 years, 2161 (64.4%) tested positive for anti-S antibodies, and 906 (27.0%) tested positive for anti-N antibodies. The total seroprevalence of anti-SARS-CoV-2 antibodies was 66.1% (95% credible interval, 64.1-68.0). Considering the presence of anti-N antibodies, we estimated that 29.9% (28.0-31.9) of the population developed antibodies after infection; the rest having developed antibodies only via vaccination. Seroprevalence estimates were similar across sexes, but differed markedly across age groups, being lowest among children aged 0-5 years (20.8% [15.5-26.7]) and highest among older adults aged ≥75 years (93.1% [89.6-96.0]). Seroprevalence of antibodies developed via infection and/or vaccination was higher among participants with a higher educational level. Conclusions: Most adults have developed anti-SARS-CoV-2 antibodies, while most teenagers and children remain vulnerable to infection. As the SARS-CoV-2 Delta variant spreads and vaccination rates stagnate, efforts are needed to address vaccine hesitancy, particularly among younger individuals and socioeconomically disadvantaged groups, and to minimize spread among children.

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A Mathematical Model of U.S. COVID-19 Deaths, Incidence and Quarantine Adjusted Herd Immunity by Age

10.21203/rs.3.rs-343570/v1 ◽

2021 ◽

Author(s):

Vikki Lovvoll

Keyword(s):

Case Reports ◽

Critical Mass ◽

Herd Immunity ◽

Age Groups ◽

P Value ◽

Younger Adults ◽

Social Distancing ◽

Social Mixing ◽

Steep Decline ◽

Disease Testing

Abstract In January 2021, a steep decline in U.S. COVID-19 deaths and case reports were noted, well before herd immunity or vaccinations would have been expected make an impact. This model predicts COVID-19 deaths and infections based on three insights. First, mortality rates differ significantly by age. Second, heterogeneous social mixing by age during quarantine may result in older adults (higher risk) to have more effectively quarantined conferring lower incidence relative to younger adults (lower risk and disproportionate essential frontline work). Third, deaths and Infection Fatality Rates may more reliably predict incidence relative to reported cases by removing uncertainty introduced from asymptomatic disease, testing availability, and false results. Age stratified IFR and deaths through December 5 were used to projected deaths (99% significance, P-value .002). Sensitivities for IFR, immune durability, and vaccinations were also modeled. By end 2020, 42% of the U.S. population had immunity differing significantly by age with 25-44-year-olds near 80%. A “critical mass” of immunity in these ages segments conferred herd immunity to other age groups. Herd immunity exists in the context of historic social distancing (quarantine). A significant percent of high-risk individuals remains susceptible and may facilitate another wave if social distancing restrictions are lifted prior to vaccination. Vaccine administrations through mid-February contributed a nominal amount to declining deaths.

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Geographical Profiles of COVID-19 Outbreak in Tokyo: An Analysis of the Primary Care Clinic–Based Point-of-Care Antibody Testing

Journal of Primary Care & Community Health ◽

10.1177/2150132720942695 ◽

2020 ◽

Vol 11 ◽

pp. 215013272094269 ◽

Cited By ~ 3

Author(s):

Morihito Takita ◽

Tomoko Matsumura ◽

Kana Yamamoto ◽

Erika Yamashita ◽

Kazutaka Hosoda ◽

...

Keyword(s):

Primary Care ◽

Point Of Care ◽

Herd Immunity ◽

Primary Care Clinic ◽

The Other ◽

Cumulative Number ◽

Antibody Testing ◽

Care Clinic ◽

Entire Cohort ◽

Pcr Test

Introduction: The primary care clinic plays a major role in triage for coronavirus disease 2019 (COVID-19), where seroprevalence in the setting of primary care clinic remains less clear. As a point-of-care immunodiagnostic test for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the serosurvey represents an alternative to the polymerase chain reaction (PCR) test to measure the magnitude of COVID-19 outbreak in the communities lacking sufficient diagnostic capability for PCR testing. Methods: We assessed seropositivity for the SARS-CoV-2 IgG between April 21 and May 20, 2020, at 2 primary care clinics in Tokyo, Japan. Results: The overall positive percentage of SARS-CoV-2 IgG was 3.83% (95% confidence interval [CI]: 2.76-5.16) for the entire cohort (n = 1071). The 23 special wards of central Tokyo exhibited a significantly higher prevalence compared with the other areas of Tokyo after classification by residence ( P = .02, 4.68% [3.08-6.79] vs 1.83 [0.68-3.95] in central and suburban Tokyo, respectively). In central Tokyo, the southern area showed the highest seroprevalence compared with the other areas (7.92% [3.48-15.01]), corresponding to the cumulative number of confirmed COVID-19 patients by PCR test reported by the Tokyo Metropolitan Government. Conclusion: The seroprevalence surveyed in this study was too low for herd immunity, suggesting the need for robust disease control and prevention. A regional-level approach, rather than state- or prefectural-level, could be of importance in ascertaining detailed profiles of the COVID-19 outbreak.

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