SARS-CoV-2 Seroprevalence in Healthcare Workers of Kaunas Hospitals during the First Wave of the COVID-19 Pandemic

Background and objective: Serologic testing is a useful additional method for the diagnosis of COVID-19. It is also used for population-based seroepidemiological studies. The objective of the study was to determine SARS-CoV-2 seroprevalence in healthcare workers of Kaunas hospitals and to compare two methods for specific SARS-CoV-2 antibody testing. Materials and Methods: A total of 432 healthcare workers in Kaunas hospitals were enrolled in this study. Each participant filled a questionnaire including questions about their demographics, contact with suspected or confirmed COVID-19, acute respiratory symptoms, and whether they contacted their general practitioner, could not come to work, or had to be hospitalized. Capillary blood was used to test for SARS-CoV-2 specific immunoglobulin G (IgG) and immunoglobulin M (IgM) a lateral flow immunoassay. Serum samples were used to test for specific IgG and IgA class immunoglobulins using semiquantitative enzyme-linked immunosorbent assay (ELISA) method. Results: 24.77% of study participants had direct contact with a suspected or confirmed case of COVID-19. A total of 64.81% of studied individuals had at least one symptom representing acute respiratory infection, compatible with COVID-19. Lateral flow immunoassay detected SARS-CoV-2 specific IgG class immunoglobulins in 1.16% of the tested group. Fever, cough, dyspnea, nausea, diarrhea, headache, conjunctivitis, muscle pain, and loss of smell and taste predominated in the anti-SARS-CoV-2 IgG-positive group. Using ELISA, specific IgG were detected in 1.32% of the tested samples. Diarrhea, loss of appetite, and loss of smell and taste sensations were the most predominant symptoms in anti-SARS-CoV-2 IgG-positive group. The positive percent agreement of the two testing methods was 50%, and negative percent agreement was 99.66%. Conclusions: 1.16% of tested healthcare workers of Kaunas hospitals were anti-SARS-CoV-2 IgG-positive. The negative percent agreement of the lateral flow immunoassay and ELISA exceeded 99%.

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Serologic SARS-CoV-2 testing in healthcare workers with positive RT-PCR test or Covid-19 related symptoms

10.1101/2020.10.25.20219113 ◽

2020 ◽

Author(s):

Giovanni Visci ◽

Vittorio Lodi ◽

Roberta Bonfiglioli ◽

Tiziana Lazzarotto ◽

Francesco S. Violante ◽

...

Keyword(s):

Healthcare Workers ◽

Lateral Flow ◽

Public Hospitals ◽

Lateral Flow Immunoassay ◽

Enzyme Linked Immunosorbent Assay ◽

Limited Information ◽

Rt Pcr ◽

Positive Serology ◽

Serologic Response ◽

Pcr Test

AbstractBackgroundLimited information is available on prevalence and determinants of serologic response to SARS-CoV-2 infection among healthcare workers (HCWs).MethodsWe analyzed the results of serologic testing with chemiluminescence immunoassay analyzer (CLIA), lateral flow immunoassay (LFIA) and enzyme-linked immunosorbent assay (ELISA) test among 544 HCWs with at least one positive RT-PCR test and 157 HCWs with Covid-19 related symptoms without a positive RT-PCR test from public hospitals in Bologna, Northern Italy. Tests were performed between March and August 2020. We fitted multivariate logistic regression models to identify determinants of positive serology.ResultsThe sensitivity of SARS-CoV-2 was 75.2% (LFIA) and 90.6% (CLIA). No differences in seropositivity were observed by sex, while older HCWs had higher positivity than other groups, and nurses had higher positivity compared to physicians, but not other HCWs. An estimated 73.4% of HCWs with Covid-19 symptoms without RT-PCR test were not infected with SARS-CoV-2.ConclusionsOur study provides the best available data on sensitivity of serologic tests and on determinants of serologic response among HCWs positive for SARS-CoV-2, and provide evidence on the low specificity of Covid-19 related symptoms to identify infected HCWs.SummaryThe sensitivity of SARS-CoV-2 lateral flow immunoassay serology in healthcare workers (HCWs) was 75.2%. Older HCWs and nurses had higher positivity than other groups. An estimated 73.4% of HCWs with Covid-19 symptoms without RT-PCR test were not infected with SARS-CoV-2.

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Development of a quantum-dot lateral flow immunoassay strip based portable fluorescence smart-phone system for ultrasensitive detection of IgM/IgG to SARS-CoV-2

10.1101/2020.07.21.20159392 ◽

2020 ◽

Author(s):

Bochao Liu ◽

Jinfeng Li ◽

Xi Tang ◽

Ze Wu ◽

Jinhui Lu ◽

...

Keyword(s):

Quantum Dot ◽

Smart Phone ◽

Protein S ◽

Lateral Flow ◽

Lateral Flow Immunoassay ◽

Serum Samples ◽

Recombinant Receptor ◽

Specific Igg ◽

Asymptomatic Individuals ◽

Novel Coronavirus

Background: Since December 2019, the outbreak of coronavirus disease (COVID-19) has been occurred by novel coronavirus (SARS-CoV-2). The rapid and sensitive immunoassays are urgently demanded for detecting specific antibodies as assistant diagnosis for primary screening of asymptomatic individuals, close contacts,suspected or recovered patients of COIVD-19 during the pandemic period. Methods: The recombinant receptor binding domain of SARS-CoV-2 spike protein (S-RBD) was used as the antigen to detect specific IgM and the mixture of recombinant nucleocapsid phosphoprotein (NP) and S-RBD were used to detect specific IgG by the newly designed quantum-dot lateral flow immunoassay strip (QD-LFIA), respectively. Results: A rapid and sensitive QD-LFIA based portable fluorescence smart-phone system was developed for detecting specific IgM/IgG to SARS-CoV-2 from 100 serum samples of COVID-19 patients and 450 plasma samples from healthy blood donors. Among 100 COVID-19 patients diagnosed with NAT previously, 3 were severe, 35 mild and 62 recovered cases. By using QD-LFIA, 78 (78%) and 99 (99%) samples from 100 COVID-19 patients serum were detected positive for anti-SARS-CoV-2 IgM or IgG, respectively, but only one sample (0.22%) was cross-reactive with S-RBD from 450 healthy blood donor plasmas that were collected from different areas of China. Conclusion: An ultrasensitive and specific QD-LFIA based portable fluorescence smart-phone system was developed fo r detection of specific IgM and IgG to SARS-CoV-2 infection, which could be used for investigating the prevalence or assistant diagnosis of COVID-19 in humans.

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Clinical Utility of a Highly Sensitive Lateral Flow Immunoassay as determined by Titer Analysis for the Detection of anti-SARS-CoV-2 Antibodies at the Point-of-Care

10.1101/2020.07.30.20163824 ◽

2020 ◽

Author(s):

Amanda Haymond ◽

Claudius Mueller ◽

Hannah Steinberg ◽

K. Alex Hodge ◽

Caitlin W Lehman ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Best Practice ◽

Point Of Care ◽

Neutralization Assay ◽

Lateral Flow ◽

Lateral Flow Immunoassay ◽

Enzyme Linked Immunosorbent Assay ◽

Antibody Testing ◽

Roc Curve Analysis ◽

Viral Neutralization

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), became a pandemic in early 2020. Lateral flow immunoassays for antibody testing have been viewed as a cheap and rapidly deployable method for determining previous infection with SARS-CoV-2; however, these assays have shown unacceptably low sensitivity. We report on nine lateral flow immunoassays currently available and compare their titer sensitivity in serum to a best-practice enzyme-linked immunosorbent assay (ELISA) and viral neutralization assay. For a small group of PCR-positive, we found two lateral flow immunoassay devices with titer sensitivity roughly equal to the ELISA; these devices were positive for all PCR-positive patients harboring SARS-CoV-2 neutralizing antibodies. One of these devices was deployed in Northern Italy to test its sensitivity and specificity in a real-world clinical setting. Using the device with fingerstick blood on a cohort of 27 hospitalized PCR-positive patients and seven hospitalized controls, ROC curve analysis gave AUC values of 0.7646 for IgG. For comparison, this assay was also tested with saliva from the same patient population and showed reduced discrimination between cases and controls with AUC values of 0.6841 for IgG. Furthermore, during viral neutralization testing, one patient was discovered to harbor autoantibodies to ACE2, with implications for how immune responses are profiled. We show here through a proof-of-concept study that these lateral flow devices can be as analytically sensitive as ELISAs and adopted into hospital protocols; however, additional improvements to these devices remain necessary before their clinical deployment.

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Immunogenicity of a third dose viral-vectored COVID-19 vaccine after receiving two-dose inactivated vaccines in healthy adults

10.1101/2021.09.16.21263692 ◽

2021 ◽

Author(s):

Ritthideach Yorsaeng ◽

Nungruthai Suntronwong ◽

Harit Phowatthanasathian ◽

Suvichada Assawakosri ◽

Sitthichai Kanokudom ◽

...

Keyword(s):

Healthcare Workers ◽

Neutralization Test ◽

Enzyme Linked Immunosorbent Assay ◽

Receptor Binding Domain ◽

Wild Type ◽

Serum Samples ◽

Inactivated Vaccines ◽

Specific Igg ◽

June July ◽

High Immunogenicity

In June 2021, Thailand was hit by the delta variant of SARS-CoV-2 resulting in the biggest wave of COVID-19. Due to the widespread delta variant, more than 600 healthcare workers had COVID-19 despite completion of two-dose CoronaVac. The Ministry of Public Health recommended that healthcare workers received a third dose of AZD1222 to increase level of protection against SARS-CoV-2. However, immune response after the third vaccination with AZD1222 are limited. In this study, sera from those who received a booster of AZD1222 in June-July 2021 were tested for SARS-CoV-2 spike receptor-binding-domain (RBD) IgG, anti-RBD total immunoglobulins and anti-spike protein 1 (S1) IgA. The neutralizing activities in a subset of serum samples were tested against the wild type and variants of concern (B.1.1.7, B.1.617.2, and B.1.351) using an enzyme-linked immunosorbent assay-based surrogate virus neutralization test. Participants who received the booster of AZD1222 possessed higher levels of spike RBD-specific IgG, total immunoglobulins, and anti-S1 IgA than that two-dose vaccines (p < 0.001). They also elicited higher neutralizing activity against the wild type and all variants of concern than those in the recipients of the two-dose vaccines. This study demonstrated a high immunogenicity of the AZD1222 booster who completed the two-dose inactivated vaccines.

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Assessment of Rapid SARS-CoV-2 Testing with Lateral Flow Immunoassay among Asymptomatic Healthcare Workers in Makati Medical Center

Asian Journal of Research in Infectious Diseases ◽

10.9734/ajrid/2020/v5i430177 ◽

2020 ◽

pp. 54-62

Author(s):

Cherry Lois M. Benjamin ◽

Jan Patrick O. Ng ◽

Elija Haziel B. Sunga ◽

Darleen M. Sy ◽

Saturnino P. Javier ◽

...

Keyword(s):

Healthcare Workers ◽

Virus Disease ◽

Medical Center ◽

Tertiary Hospital ◽

The Philippines ◽

Lateral Flow ◽

Lateral Flow Immunoassay ◽

Antibody Testing ◽

Global Pandemic ◽

History Of

Aims: Corona Virus Disease-19 (COVID-19) is a global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While the gold standard for diagnosis is still reverse transcription Polymerase Chain Reaction (RT-PCR), it is not readily available. Serologic testing is considered to be a faster method of identifying individuals who may have been exposed and developed antibodies against SARS-CoV-2. Methodology: This was an ambirectional observational study aimed to determine the prevalence of exposure to COVID-19 infection among asymptomatic healthcare workers in Makati Medical Center, a tertiary hospital in the Philippines, using rapid antibody testing (lateral flow immunoassay) in May 2020. Results: A total of 1557 asymptomatic healthcare workers were included in the study. Majority belonged to the paramedical group (52%). Twenty (1.3%) healthcare workers were IgM positive while 17 (1.1%) tested positive for IgG. Three healthcare workers (0.2%) tested positive for both antibodies. Participants with history of being quarantined who tested positive for either IgM or IgG were significantly higher compared to those who tested negative for both antibodies (55%, 33.3%, 41.2% vs 28.5%, p = 0.036). Those with diabetes had 6.8 times higher risk of being IgM positive and IgG negative (p=0.001). In addition, those with diabetes were more likely (13.6 times) to be positive in both tests (p=0.034). Conclusion: There was a low prevalence (2.6%) of COVID-19 infection among healthcare workers of Makati Medical Center. Among those with positive serologic test, diabetes mellitus, history of exposure and history of quarantine were risk factors associated with COVID-19 infection.

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TBE in Sweden

Tick-borne encephalitis - The Book ◽

10.33442/26613980_12b32-3 ◽

2020 ◽

Keyword(s):

Genetic Characterization ◽

Immunoglobulin M ◽

Enzyme Linked Immunosorbent Assay ◽

Second Phase ◽

Serum Samples ◽

Tick Borne Encephalitis ◽

Specific Immunoglobulin ◽

Tick Borne Encephalitis Virus ◽

First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

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Comparative Analysis of the Euroimmun CXCL13 Enzyme-Linked Immunosorbent Assay and the ReaScan Lateral Flow Immunoassay for Diagnosis of Lyme Neuroborreliosis

Journal of Clinical Microbiology ◽

10.1128/jcm.00207-20 ◽

2020 ◽

Vol 58 (9) ◽

Author(s):

Katharina Ziegler ◽

Anca Rath ◽

Christoph Schoerner ◽

Renate Meyer ◽

Thomas Bertsch ◽

...

Keyword(s):

Immunosorbent Assay ◽

Roc Curve ◽

Point Of Care ◽

Lateral Flow ◽

Lyme Neuroborreliosis ◽

Diagnostic Tools ◽

Lateral Flow Immunoassay ◽

Enzyme Linked Immunosorbent Assay ◽

European Federation ◽

Point Of Care Test

ABSTRACT Diagnosis of Lyme neuroborreliosis (LNB) is challenging, as long as Borrelia-specific intrathecal antibodies are not yet detectable. The chemokine CXCL13 is elevated in the cerebrospinal fluid (CSF) of LNB patients. Here, we compared the performances of the Euroimmun CXCL13 enzyme-linked immunosorbent assay (CXCL13 ELISA) and the ReaScan CXCL13 lateral flow immunoassay (CXCL13 LFA), a rapid point-of-care test, to support the diagnosis of LNB. In a dual-center case-control study, CSF samples from 90 patients (34 with definite LNB, 10 with possible LNB, and 46 with other central nervous system [CNS] diseases [non-LNB group]) were analyzed with the CXCL13 ELISA and the CXCL13 LFA. Classification of patients followed the European Federation of Neurological Societies (EFNS) guidelines on LNB. The CXCL13 ELISA detected elevated CXCL13 levels in all patients with definite LNB (median, 1,409 pg/ml) compared to the non-LNB controls (median, 20.7 pg/ml; P < 0.0001), with a sensitivity of 100% and a specificity of 84.8% (cutoff value, 78.6 pg/ml; area under the receiver operating characteristic [ROC] curve, 0.93). Similarly, the CXCL13 LFA yielded elevated CXCL13 levels in 31 patients with definite LNB (median arbitrary value, 223.5) compared to the non-LNB control patients (median arbitrary value, 0; P < 0.0001) and had a sensitivity and specificity of 91.2% and 93.5%, respectively (cutoff arbitrary value, 22.5; area under the ROC curve, 0.94). The correlation between the CXCL13 levels obtained by ELISA and LFA was strong (Spearman correlation coefficient r = 0.89; P < 0.0001). The CXCL13 ELISA and the CXCL13 LFA are comparable diagnostic tools for the detection of CXCL13 in the CSF of patients with definite LNB. The advantage of the CXCL13 LFA is the shorter time to result.

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Diagnosis of Dengue Virus Infection by Detection of Specific Immunoglobulin M (IgM) and IgA Antibodies in Serum and Saliva

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.2.317-322.2003 ◽

2003 ◽

Vol 10 (2) ◽

pp. 317-322 ◽

Cited By ~ 83

Author(s):

Angel Balmaseda ◽

María G. Guzmán ◽

Samantha Hammond ◽

Guillermo Robleto ◽

Carolina Flores ◽

...

Keyword(s):

Dengue Virus ◽

Immunoglobulin M ◽

Antibody Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Control Group ◽

Serum Samples ◽

Diagnostic Modality ◽

Iga Antibodies ◽

Specific Immunoglobulin ◽

Feasible Alternative

ABSTRACT To evaluate alternative approaches to the serological diagnosis of dengue virus (DEN) infection, the detection of DEN-specific immunoglobulin M (IgM) and IgA antibodies in serum and saliva specimens was assessed in 147 patients with symptoms of DEN infection seen at the Ministry of Health in Nicaragua. Seventy-two serum samples were determined to be positive for anti-DEN antibodies by IgM capture enzyme-linked immunosorbent assay, the routine diagnostic procedure. Serum and saliva specimens were obtained from 50 healthy adults as additional controls. IgM was detected in the saliva of 65 of the 72 serum IgM-positive cases, 6 of the 75 serum IgM-negative cases, and none of the control group, resulting in a sensitivity of 90.3% and a specificity of 92.0% and demonstrating that salivary IgM is a useful diagnostic marker for DEN infection. Detection of IgA in serum may be another feasible alternative for the diagnosis of DEN infection, with serum IgA found in 68 (94.4%) of the IgM-positive cases. In contrast, detection of IgA in saliva was not found to be a useful tool for DEN diagnosis in the present study. Further studies of the kinetics of antibody detection in another set of 151 paired acute- and convalescent-phase serum samples showed that DEN-specific IgA antibodies were detected in more acute-phase samples than were IgM antibodies. Thus, we conclude that DEN-specific IgA in serum is a potential diagnostic target. Furthermore, given that saliva is a readily obtainable, noninvasive specimen, detection of DEN-specific salivary IgM should be considered a useful, cheaper diagnostic modality with similar sensitivity and specificity to IgM detection in serum.

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Immunogenicity of heterologous prime/booster-inactivated and adenoviral-vectored COVID-19 vaccine: real-world data

10.21203/rs.3.rs-785693/v1 ◽

2021 ◽

Author(s):

Nasamon Wanlapakorn ◽

Nungruthai Suntronwong ◽

Harit Phowatthanasathian ◽

Ritthideach Yorsang ◽

Thanunrat Thongmee ◽

...

Keyword(s):

Neutralizing Antibody ◽

Enzyme Linked Immunosorbent Assay ◽

Antibody Activity ◽

Serum Samples ◽

Real World Data ◽

Comparison Groups ◽

Chemiluminescent Microparticle Immunoassay ◽

Specific Igg ◽

Vectored Vaccine ◽

Sera Samples

Abstract Limited data are available on the responses to heterologous vaccine regimens for SARS-CoV-2, especially among countries using inactivated and adenoviral-vectored vaccines. A total of 77 participants who received heterologous prime/booster-inactivated COVID-19 vaccine and adenoviral-vectored vaccine were enrolled in our study. There were two comparison groups vaccinated with the homologous CoronaVac (N = 79) and AZD1222 (N = 80) regimen. All sera samples were tested for SARS-CoV-2 spike receptor-binding-domain (RBD) IgG using a chemiluminescent microparticle immunoassay (CMIA). The neutralizing activity in a subset of serum samples was tested against the original Wuhan strain and variants of concern, B.1.1.7 and B.1.351, using an enzyme-linked immunosorbent assay (ELISA)-based surrogate virus neutralization test (sVNT). The CoronaVac followed by the AZD1222 vaccine induced higher levels of spike RBD-specific IgG than that of two-dose CoronaVac or AZD1222 vaccines (p < 0.001). Sera samples of the CoronaVac/AZD1222 vaccine recipients elicited higher neutralizing antibody activity against the original Wuhan and the B.1.351 strain than in the recipients of the two-dose CoronaVac or AZD1222. Following the inactivated CoronaVac/adenoviral-vectored (AZD1222) vaccination administered 14–72 days apart, participants receiving the heterologous vaccine regimen had higher spike RBD-specific IgG and neutralizing activities than the homologous CoronaVac vaccine recipients.

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Development of an Enzyme-Linked Immunosorbent Assay for Immunoglobulin M Antibodies against Measles Virus

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.3.439-442.2003 ◽

2003 ◽

Vol 10 (3) ◽

pp. 439-442 ◽

Cited By ~ 3

Author(s):

F. Roodbari ◽

M. H. Roustai ◽

A. Mostafaie ◽

H. Soleimanjdahi ◽

R. Sarrami Foroshani ◽

...

Keyword(s):

Immunosorbent Assay ◽

Neutralizing Antibodies ◽

Measles Virus ◽

Clinical Symptoms ◽

Maculopapular Rash ◽

Immunoglobulin M ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Vaccination Programs ◽

Elisa System

ABSTRACT Measles is a highly contagious respiratory virus infection, with typical clinical symptoms including maculopapular rash, fever, cough, coryza, and conjunctivitis. Despite implementation of widespread vaccination programs throughout the world, the rates of global morbidity and mortality are still considerable. This study was performed to design a reliable indirect enzyme-linked immunosorbent assay (ELISA) to measure measles-specific immunoglobulin M (IgM). First, human IgM was purified, and then an anti-IgM antibody was produced in rabbits and purified in a multistep process. The rabbit IgG against human IgM was conjugated with peroxidase. Measles virus-infected Vero cells produced viral antigen. One hundred serum samples from infants of 9 to 18 months of age, mostly vaccinated, were evaluated for determining the presence of specific IgM antibodies against measles virus. The samples were also evaluated for neutralizing antibodies against measles virus by a microneutralization test (MNT). By comparing the results of the ELISA with those of MNT, it was demonstrated that ELISA had a sensitivity and specificity of 100 and 92%, respectively. On the other hand, when the results obtained by our ELISA system were compared with those of an imported measles virus IgM ELISA kit (EIAgen; Adaltis Italia SPa, Bologna, Italy), a high level of agreement was shown (k = 0.926).

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