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

2020 ◽  
Author(s):  
Sophie Uyoga ◽  
Ifedayo M.O. Adetifa ◽  
Henry K. Karanja ◽  
James Nyagwange ◽  
James Tuju ◽  
...  
Keyword(s):  
Blood Donors ◽  
Igg Antibodies ◽  
Multilevel Regression ◽  
Antibody Prevalence ◽  
Assay Sensitivity ◽  
Epidemic Curve ◽  
Assay Performance ◽  
Median Date ◽  
Residual Blood ◽  
Performance Results

Background There are no data on SARS-CoV-2 seroprevalence in Africa though the COVID-19 epidemic curve and reported mortality differ from patterns seen elsewhere. We estimated the anti-SARS-CoV-2 antibody prevalence among blood donors in Kenya. Methods We measured anti-SARS-CoV-2 spike IgG prevalence by ELISA on residual blood donor samples obtained between April 30 and June 16, 2020. Assay sensitivity and specificity were 83% (95% CI 59, 96%) and 99.0% (95% CI 98.1, 99.5%), respectively. National seroprevalence was estimated using Bayesian multilevel regression and post-stratification to account for non-random sampling with respect to age, sex and region, adjusted for assay performance. Results Complete data were available for 3098 of 3174 donors, aged 15-64 years. By comparison with the Kenyan population, the sample over-represented males (82% versus 49%), adults aged 25-34 years (40% versus 27%) and residents of coastal Counties (49% versus 9%). Crude overall seroprevalence was 5.6% (174/3098). Population-weighted, test-adjusted national seroprevalence was 5.2% (95% CI 3.7, 7.1%). Seroprevalence 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 in Kenya had SARS-CoV-2 antibodies 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 reported in parts of Europe and America when seroprevalence was similar.

scholarly journals Seroprevalence of Antibodies to SARS-CoV-2 among Health Care Workers in Kenya

2021 ◽  
Author(s):  
Anthony O. Etyang ◽  
Ruth Lucinde ◽  
Henry Karanja ◽  
Catherine Kalu ◽  
Daisy Mugo ◽  
...  
Keyword(s):  
Health Care ◽  
Health Care Workers ◽  
Bayesian Modeling ◽  
Igg Antibodies ◽  
Multivariable Model ◽  
High Seroprevalence ◽  
Assay Sensitivity ◽  
Care Workers ◽  
Assay Performance ◽  
Prevalence Estimates

ABSTRACTBackgroundFew studies have assessed the seroprevalence of antibodies against SARS-CoV-2 among Health Care Workers (HCWs) in Africa. We report findings from a survey among HCWs in three counties in Kenya.MethodsWe recruited 684 HCWs from Kilifi (rural), Busia (rural) and Nairobi (urban) counties. The serosurvey was conducted between 30th July 2020 and 4th December 2020. We tested for IgG antibodies to SARS-CoV-2 spike protein using ELISA. Assay sensitivity and specificity were 93% (95% CI 88-96%) and 99% (95% CI 98-99.5%), respectively. We adjusted prevalence estimates using Bayesian modeling to account for assay performance.ResultsCrude overall seroprevalence was 19.7% (135/684). After adjustment for assay performance seroprevalence was 20.8% (95% CI 17.5-24.4%). Seroprevalence varied significantly (p<0.001) by site: 43.8% (CI 35.8-52.2%) in Nairobi, 12.6% (CI 8.8-17.1%) in Busia and 11.5% (CI 7.2-17.6%) in Kilifi. In a multivariable model controlling for age, sex and site, professional cadre was not associated with differences in seroprevalence.ConclusionThese initial data demonstrate a high seroprevalence of antibodies to SARS-CoV-2 among HCWs in Kenya. There was significant variation in seroprevalence by region, but not by cadre.

scholarly journals Seroprevalence of Hepatitis E IgG antibodies among Voluntary Blood Donors in a tertiary hospital

2017 ◽  
Vol 4 (5) ◽  
pp. A599-A603
Author(s):  
Chinnadurai Peermohd Luck ◽  
SrirangramasamyJamuna Rani ◽  
Duraipandian Jeyakumari ◽  
Madasamy Balamurugan ◽  
Aruna V Padmavathi ◽  
...  
Keyword(s):  
Blood Donors ◽  
Hepatitis E ◽  
Tertiary Hospital ◽  
Igg Antibodies

Detection and Titration of Human Herpesvirus-8–Specific Antibodies in Sera From Blood Donors, Acquired Immunodeficiency Syndrome Patients, and Kaposi's Sarcoma Patients Using a Whole Virus Enzyme-Linked Immunosorbent Assay

Blood ◽  
1998 ◽  
Vol 92 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Louise G. Chatlynne ◽  
William Lapps ◽  
Michael Handy ◽  
Yao Q. Huang ◽  
Rizwan Masood ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Kaposi's Sarcoma ◽  
Blood Donors ◽  
Human Herpesvirus ◽  
Kaposi’S Sarcoma ◽  
Antibody Detection ◽  
Human Herpesvirus 8 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Herpesvirus 8

A human herpesvirus-8 (HHV-8) enzyme-linked immunosorbent assay (ELISA) with a whole virus lysate as antigen was developed and used to measure the seroprevalence rate and levels of IgG antibodies to HHV-8 in sera/plasma of various patient groups and blood donors. The virus antigen was prepared from the KS-1 cell line, which produces lytic virus, and therefore contains a broad array of viral proteins. Seroprevalence studies using this ELISA showed the following: 10 of 91 blood donors (11%) had an average HHV-8 antibody titer of 118; 67 of 72 (93%) classic Kaposi's sarcoma (KS) patients were positive with an average titer of 14,111; and 57 of 62 (92%) KS/human immunodeficiency virus (HIV) patients were positive with an average titer of 4,000. A study on a very limited number of serial serum samples from patients before and after diagnosis with KS showed highly elevated antibody titers to HHV-8 virus after KS lesions developed. Preliminary data show that 50% of the sera from HIV-1+ homosexual patients contain IgG antibodies to HHV-8 suggesting that this population is at high risk for developing KS. Antibody results correlated well with the confirmatory immunofluorescent assays (IFA) using KS-1 cells as the substrate. This HHV-8 IgG antibody detection ELISA is sensitive and specific and does not cross-react with Epstein-Barr virus (EBV) or other human herpesviruses. The results of this HHV-8 antibody survey suggest that this rapid ELISA assay can be used to screen large numbers of sera to find those at risk for developing KS.

scholarly journals IgG Antibodies against Deamidated Gliadin Peptides for Diagnosis of Celiac Disease in Patients with IgA Deficiency

2010 ◽  
Vol 56 (3) ◽  
pp. 464-468 ◽  
Author(s):  
Danilo Villalta ◽  
Elio Tonutti ◽  
Christian Prause ◽  
Sibylle Koletzko ◽  
H Holm Uhlig ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Blood Donors ◽  
Tissue Transglutaminase ◽  
Iga Deficiency ◽  
Diagnostic Sensitivity ◽  
Igg Antibodies ◽  
Diagnostic Specificity ◽  
Gliadin Peptides ◽  
Endomysium Antibodies ◽  
Monkey Esophagus

AbstractBackground: Assays for IgG antibodies against deamidated gliadin (IgG-anti-dGli) are comparable in performance with tests detecting IgA antibodies against tissue transglutaminase (IgA-anti-tTG) in diagnosing celiac disease (CD). IgA-anti-tTG are absent in IgA deficiency, a condition often associated with CD. In IgA deficiency, IgG-anti-tTG, which have a lower overall diagnostic accuracy, are routinely measured. We examined whether IgG-anti-dGli would be useful for diagnosing CD in patients with IgA deficiency.Methods: We studied 34 IgA-deficient CD patients, 185 IgA-competent newly diagnosed children with CD, 316 children without CD, 400 adult blood donors, and 6 control IgA-deficient individuals without CD. Anti-dGli and anti-tTG were measured by ELISA, and endomysium antibodies (EmA) were measured by immunofluorescence on monkey esophagus (IgA as well as IgG class for all antibodies). We calculated diagnostic sensitivity (percentage of patients above cutoff with 95% CIs) according to age-specific cutoffs for 95% diagnostic specificity and according to cutoffs proposed by the manufacturer of the assays.Results: No IgA-deficient CD patients were positive for any IgA-based antibody assay. Diagnostic sensitivity of IgG-anti-tTG was 91.2% (95% CI 76.3%–97.7%) according to age-specific cutoffs and 82.4% (66.1%–92.0%) according to manufacturer cutoffs. The diagnostic sensitivity of IgG-EmA was 75.8% (58.8%–87.4%) and the sensitivity of IgG-anti-dGli was 88.2% (72.8%–95.9%) according to both cutoffs.Conclusions: IgG-anti-dGli and IgG-anti-tTG have comparable diagnostic sensitivities for IgA-deficient celiac patients. IgG-anti-dGli may be useful for diagnosing CD in IgA-deficient patients.

Hepatitis C Antibody Prevalence in Saudi Arabian Blood Donors

Vox Sanguinis ◽  
1991 ◽  
Vol 61 (4) ◽  
pp. 279-279 ◽  
Author(s):  
S.S. Bernvil ◽  
V.J. Andrews ◽  
A.A. Kariem
Keyword(s):  
Hepatitis C ◽  
Blood Donors ◽  
Saudi Arabian ◽  
Antibody Prevalence

scholarly journals Seroprevalences of Herpes Simplex Virus Type 2, Five Oncogenic Human Papillomaviruses, and Chlamydia trachomatis in Katowice, Poland

2008 ◽  
Vol 15 (4) ◽  
pp. 675-680 ◽  
Author(s):  
Staffan Görander ◽  
Teresa Lagergård ◽  
Malgorzata Romanik ◽  
Raphael P. Viscidi ◽  
Gayane Martirosian ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Chlamydia Trachomatis ◽  
Blood Donors ◽  
Human Papillomaviruses ◽  
Igg Antibodies ◽  
Hpv Types ◽  
Simplex Virus ◽  
Oncogenic Hpv

ABSTRACT Herpes simplex virus type 2 (HSV-2), human papillomaviruses (HPVs), and Chlamydia trachomatis are the most common pathogens causing sexually transmitted infections (STIs). There is limited information about the prevalences of these STIs in Poland. Here, we estimated the occurrence of immunoglobulin G (IgG) antibodies against HSV-2, HPV, and C. trachomatis in 199 blood donors and 110 patients of both genders attending an STI clinic in Katowice in southern Poland. The seroprevalences of HSV-2 were 5% for blood donors and 14% in the STI cohort. The seroprevalences of the five potentially oncogenic HPV types 16, 18, 31, 35, and 51 were 15%, 7%, 5%, 5%, and 17%, respectively, in blood donors and 37%, 8%, 12%, 5%, and 21%, respectively, in the STI cohort. The majority of HPV-infected individuals showed antibodies against more than one type, i.e., had been infected with multiple HPV types. Anti-C. trachomatis IgG antibodies were detected in 6% of blood donors and 13% of individuals attending the STI clinic. The relatively high prevalence of HPV-51 may have implications for future vaccine programs, as the newly introduced HPV vaccines are based on the potentially oncogenic HPV types 16 and 18.

D-Dimer Testing for Deep Venous Thrombosis: A Metaanalysis

2004 ◽  
Vol 50 (7) ◽  
pp. 1136-1147 ◽  
Author(s):  
Steven W Heim ◽  
Joel M Schectman ◽  
Mir S Siadaty ◽  
John T Philbrick
Keyword(s):  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Test Performance ◽  
Reference Standard ◽  
Assay Sensitivity ◽  
Predictive Values ◽  
Assay Performance ◽  
Level 1 ◽  
D Dimer ◽  
Rule Out

Abstract Background: The use of D-dimer assays as a rule-out test for deep venous thrombosis (DVT) is controversial. To clarify this issue we performed a systematic review of the relevant literature. Methods: We identified eligible studies, using MEDLINE entries from February 1995 through October 2003, supplemented by a review of bibliographies of relevant articles. Studies reporting accuracy evaluations comparing D-dimer test results with lower extremity ultrasound or venography in symptomatic patients with suspected acute DVT were selected for review. Two reviewers critically appraised each study independently according to previously established methodologic standards for diagnostic test research. Those studies judged to be of highest quality were designated Level 1. Results: The 23 Level 1 studies reported data on 21 different D-dimer assays. There was wide variation in assay sensitivity, specificity, and negative predictive values, and major differences in methodology of reviewed studies. A multivariate analysis of assay performance, controlling for sample size, DVT prevalence, reference standard, and patient mix, found few differences among the assays in effect on test performance as measured by diagnostic odds ratio. Increasing prevalence of DVT was associated with poorer test performance (P = 0.01), whereas the choice of venography as the reference standard was associated with better test performance (P &lt;0.005). Conclusions: Explanations for the wide variation in assay performance include differences in biochemical and technical characteristics of the assays, heterogeneity and small size of patient groups, and bias introduced by choice of reference standards. Assay sensitivity and negative predictive value were frequently &lt;90%, uncharacteristic of a good rule-out test. General use of D-dimer assays as a stand-alone test for the diagnosis of DVT is not supported by the literature.

scholarly journals Seroprevalence of hepatitis E virus among blood donors on Corsica, France, 2017

2020 ◽  
Vol 25 (5) ◽  
Author(s):  
Lisandru Capai ◽  
Nathanaël Hozé ◽  
Jacques Chiaroni ◽  
Sylvie Gross ◽  
Rachid Djoudi ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Blood Donors ◽  
Acute Viral Hepatitis ◽  
Hepatitis E ◽  
Igg Antibodies ◽  
Zoonotic Pathogen ◽  
Force Of Infection ◽  
Hyperendemic Area ◽  
Annual Probability ◽  
Significant Difference

Background Hepatitis E virus (HEV) is an emerging zoonotic pathogen and an important cause of acute viral hepatitis in European countries. Corsica Island has been previously identified as a hyperendemic area for HEV. Aim Our aim was to characterise the prevalence and titres of IgG antibodies to HEV among blood donors on Corsica and establish a model of the annual force of infection. Methods Between September 2017 and January 2018, 2,705 blood donations were tested for anti-HEV IgG using the Wantai HEV IgG enzyme immunoassay. Results The overall seroprevalence was 56.1%. In multivariate analysis, seroprevalence was higher in men than in women (60.0% vs 52.2%; p < 0.01), increased with age and was significantly higher among donors born on Corsica (60.6% vs 53.2%; p < 0.01). No significant difference was observed between the five districts of the island. IgG anti-HEV titres were mostly low (70% of positive donors had titres < 3 IU/mL). In Corsican natives, increasing seroprevalence by age could be explained by models capturing a loss of immunity (annual probability of infection: 4.5%; duration of immunity: 55 years) or by age-specific probabilities of infection (3.8% for children, 1.3% for adults). Conclusion We confirmed the high HEV seroprevalence on Corsica and identified three aspects that should be further explored: (i) the epidemiology in those younger than 18 years, (ii) common sources of contamination, in particular drinking water, that may explain the wide exposure of the population, and (iii) the actual protection afforded by the low IgG titres observed and the potential susceptibility to secondary HEV infection.

scholarly journals Prevalence of rubella antibodies among school girls in Sana’a, Republic of Yemen

2003 ◽  
Vol 9 (1-2) ◽  
pp. 148-151
Author(s):  
T. A. Sallam ◽  
M. S. Benbrake ◽  
K. S. Al Shaibani ◽  
A. A. Al Hababi
Keyword(s):  
Immunosorbent Assay ◽  
Age Groups ◽  
Female Students ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Antibody Prevalence ◽  
Recent Exposure ◽  
School Girls ◽  
Age Range ◽  
Sera Samples

To determine the prevalence of rubella antibodies and age of exposure to rubella among Yemeni schoolgirls, we studied the sera samples of 323 female students [age range 11-21 years; mean age 16.26 +/- 1.89 years] drawn from three schools in Sana’a. All samples were screened for rubella IgG antibodies using enzyme linked immunosorbent assay and, if negative, for IgM in order to exclude the possibility of recent exposure. Of 323 sera, 296 [91.64%] were positive for rubella IgG. All IgG negative sera were also IgM negative. Comparable antibody prevalence was observed in all age groups. The prevalence of rubella IgG among Yemeni schoolgirls is high, with most becoming immune between the ages of 11 and 21 years. Although the age of exposure seems to be </= 13 years, further investigation is needed to confirm this

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