scholarly journals Prevalence of IgG and IgM antibodies to SARS-CoV-2 among clinic staff and patients

Author(s):  
Marcus Inyama Asuquo ◽  
Emmanuel Effa ◽  
Akaninyene Otu ◽  
Okokon Ita ◽  
Ubong Udoh ◽  
...  

The coronavirus disease 2019 (COVID-19) is now a pandemic with devastating social and economic consequences. The extent of the spread of COVID-19 within populations is uncertain since diagnostic tests have not been carried out on all eligible persons and doing such diagnostic tests on everyone is much less feasible in developing countries such as Nigeria. Tests for antibodies to SARS-CoV-2, the virus that causes COVID-19, are more affordable, readily available, and require minimal training than current diagnostic tests. Employing a seroepidemiological strategy, serological tests were conducted on 66 volunteering staff and patients at the University of Calabar Teaching Hospital (UCTH), a Federal Government owned tertiary healthcare facility, to determine the extent of exposure to SARS-CoV-2, from 17th to 25th June 2020. Using a COVID-19 IgG/IgM Rapid Test Cassette with emergency use authorization (EUA) from the Food and Drug Administration (FDA) of the United States, it was observed that of the 66 samples tested, 5 (7.6%) were both IgG and IgM positive and 17 (26%) were IgG positive. Moreover, for 44 of the 66 participants, simultaneous tests were carried out using a rapid test kit from a different manufacturer but without FDA-EUA and all the results completely matched with the FDA-EUA kit, except one case where the FDA-EUA kit showed positive for both IgG and IgM while the other kit was positive only for IgM. The 26% positive IgG indicates a high exposure rate for the hospital staff and patients and points to community transmission where the facility is situated. Hence, immediate activation of WHO guidelines for controlling community transmission is called for. These results can further serve as a pilot study to guide public health policies in response to COVID-19 pandemic in both the general population and in healthcare settings.

Author(s):  
Runjia Shi ◽  
Zhongna Yu ◽  
Harvey Ho ◽  
Wei Wu ◽  
Jun Wang ◽  
...  

The objective of this study was to investigate the occurrence of aflatoxin M1 (AFM1) in Chinese liquid milk products. A total of 190 liquid milk samples, including 168 ultra-high temperature treated (UHT) milk samples and 22 pasteurized milk (PM) samples were collected in August 2019. A screening assay with the Charm Rapid Test Kit and a confirmation method with high-performance liquid chromatography (HPLC) were used for AFM1 analysis. Nine (4.74%) samples were screened positive, of which 5 (2.11%) samples were confirmed with concentration levels of 0.022-0.049μg/kg. The AFM1 levels confirmed were all below the maximum residue levels (MRLs) set by China, the European Union (EU), the United States of America (USA), and the Codex Alimentarius Commission (CAC). The detection rate of AFM1 in domestic milk samples was 3.39%, while no AFM1 was detected in samples of imported milk. The prevalence of AFM1 detected in three groups were: Group I (2.70%, the major brands of China ), Group II (4.55%, the local city domestic brands) and Group III (0, the imported brands into China). The detection rate of AFM1 in PM samples (9.09%) was significantly higher than UHT samples (1.19%) ( P < 0.05). Although the residue level of AFM1 in none of the samples exceeded the MRLs, the higher detection rate in local Chinese brands, especially in PM samples, deserves the attention of the Chinese government and consumers.


2020 ◽  
Author(s):  
Berhanu Nega Alemu ◽  
Adamu Addissie ◽  
Gemechis Mamo ◽  
Negussie Deyessa ◽  
Tamrat Abebe ◽  
...  

AbstractBackgroundAnti-SARS-CoV-2 antibody tests are being increasingly used for sero-epidemiological purposes to provide better understanding of the extent of the infection in the community, and monitoring the progression of the COVID-19 epidemic. We conducted sero-prevalence study to estimate prior infection with with SARS-CoV-2 in Addis Ababa.MethodsA cross-sectional study was done from April 23 to 28, 2020 among 301 randomly selected residents of Addis Ababa; with no known history of contact with confirmed COVID-19 person. Interviews on socio demographic and behavioural risk factor followed by serological tests were performed for SARS-CoV-2 IgM, and IgG antibodies, using COVID-19 IgG/IgM Rapid Test Cassette. The test has sensitivity of 87·9% and specificity of 100% for lgM; and a sensitivity of 97·2% and specificity of 100% for IgG. RT-PCR test was also done on combined nasopharyngeal and oropharengeal swabs as an important public health consideration.FindingsThe unadjusted antibody-based crude SARS-CoV-2 prevalence was 7·6% and the adjusted true SARS-CoV-2 prevalence was estimated at 8·8% (95% CI 5·5%-11·6%) for the study population. Higher sero-prevalence were observed for males (9.0%), age below 50 years (8.2%), students and unemployed (15.6%), those with primary education (12.1%), smokers (7.8%), alcohol consumers (8.6%), chatt-chewers (13.6%) and shish smokers (18.8%). Seroprevalence was not significantly associated neither with socio-demographic not behavioral characteristics. According to the findings, possibly more individuals had been infected in Addis Ababa than what was being detected and reported by RT-PCR test suggestive of community transmission. The use of serological test for epidemiological estimation of the extent of SARS-CoV-2 epidemic gives a more precise estimate of magnitude which would be used for further monitoring and surveillance of the magnitude of the SARS CoV-2 infection.


2020 ◽  
Author(s):  
Sérgio Monteiro de Almeida ◽  
Regiane Nogueira Spalanzani ◽  
Meri Bordignon Nogueira ◽  
Beatriz Sanada Spiri ◽  
Barbara Maria Cavalli ◽  
...  

Abstract Background. This study aimed to assess the diagnostic performance of lateral flow immunochromatographic assays (LFA) of four different manufacturers to identify SARS-CoV-2 antibodies (IgM, IgG or total), comparing them with the nucleic acid amplification test (NAAT) or clinical defined (definite or probable SARS-CoV-2 infection respectively). Methods. 119 serum samples were randomly selected by convenience and distributed in the groups: (1) Group with SARS-CoV-2 infection [n=82; RT-qPCR positive (definite, n=70), and probable (n=12)]; (2) other diseases [n= 27; other viruses identified (n=8), SARS of other etiologies (n=19)]; (3) healthy control group (n=10). LFA essays of four manufacturers were compared: MedTest Coronavírus (COVID-19) IgG/IgM (MedLevensohn, Brazil); COVID-19 IgG/IgM ECO Test (Ecodiagnóstica, Brazil); Camtech COVID-19 IgM/IgG Rapid Test Kit (Camtech Diagnostics Pte Ltd, Singapore); and one Step COVID-19 Test for total antibodies (Guangzhou Wondfo Biotech Co, China).Results. The four tests studied showed high diagnostic performance characteristics for the diagnoses of definite or probable SARS-CoV-2 infection. The best measures were for the Wondfo test: sensitivity (86.59%; 95%CI, 77.26-93.11%); specificity (100%; 90.51-100%); DOR (257; 60-1008); LR+ (33.43; 4.82-231.85); LR− (0.13; 0.08 - 0.23); accuracy (90.76%; 84.06- 95.29%); Matthews Correlation coefficient (MCC) 0.82. Although considering only the probable SARS-CoV-2 infection (PCR-) cases, all the kits studied showed limited values.Conclusion. Our data demonstrate the excellent performance of LFA for the diagnoses of definite or probable SARS-CoV-2 infection. There was substantial heterogeneity in sensitivities of IgM and IgG antibodies among the manufacturers. LFA tests cannot replace molecular diagnostics, but should be used as additional screening tool.


2020 ◽  
Author(s):  
Sérgio Monteiro de Almeida ◽  
Regiane Nogueira Spalanzani ◽  
Meri Bordignon Nogueira ◽  
Beatriz Sanada Spiri ◽  
Barbara Maria Cavalli ◽  
...  

Abstract Background. This study aimed to assess the diagnostic performance of lateral flow immunochromatographic assays (LFA) of four different manufacturers to identify SARS-CoV-2 antibodies (IgM, IgG or total), comparing them with the nucleic acid amplification test (NAAT) or clinical defined (definite or probable SARS-CoV-2 infection respectively). Methods. 119 serum samples were randomly selected by convenience and distributed in the groups: (1) Group with SARS-CoV-2 infection [n=82; RT-qPCR positive (definite, n=70), and probable (n=12)]; (2) other diseases [n= 27; other viruses identified (n=8), SARS of other etiologies (n=19)]; (3) healthy control group (n=10). LFA essays of four manufacturers were compared: MedTest Coronavírus (COVID-19) IgG/IgM (MedLevensohn, Brazil); COVID-19 IgG/IgM ECO Test (Ecodiagnóstica, Brazil); Camtech COVID-19 IgM/IgG Rapid Test Kit (Camtech Diagnostics Pte Ltd, Singapore); and one Step COVID-19 Test for total antibodies (Guangzhou Wondfo Biotech Co, China).Results. The four tests studied showed high diagnostic performance characteristics for the diagnoses of definite or probable SARS-CoV-2 infection. The best measures were for the Wondfo test: sensitivity (86.59%; 95%CI, 77.26-93.11%); specificity (100%; 90.51-100%); DOR (257; 60-1008); LR+ (33.43; 4.82-231.85); LR− (0.13; 0.08 - 0.23); accuracy (90.76%; 84.06- 95.29%); Matthews Correlation coefficient (MCC) 0.82. Although considering only the probable SARS-CoV-2 infection (PCR-) cases, all the kits studied showed limited values.Conclusion. Our data demonstrate the excellent performance of LFA for the diagnoses of definite or probable SARS-CoV-2 infection. There was substantial heterogeneity in sensitivities of IgM and IgG antibodies among the manufacturers. LFA tests cannot replace molecular diagnostics, but should be used as additional screening tool.


Author(s):  
Sérgio Monteiro de Almeida ◽  
Regiane Nogueira Spalanzani ◽  
Meri Bordignon Nogueira ◽  
Beatriz Sanada ◽  
Barbara Maria Cavalli ◽  
...  

To assess the diagnostic performance of lateral flow immunochromatographic assays (LFA) of four different manufacturers to identify SARS-CoV-2 antibodies (IgM, IgG or total), comparing them with the nucleic acid amplification test (NAAT) or clinical defined (definite or probable SARS-CoV-2 infection respectively). Methods. 119 serum samples were randomly selected by convenience and distributed in the groups: (1) Group with SARS-CoV-2 infection [n=82; RT-qPCR positive (definite, n=70), and probable (n=12)]; (2) other diseases [n= 27; other viruses identified (n=8), SARS of other etiologies (n=19)]; (3) healthy control group (n=10). LFA essays of four manufacturers were compared: MedTest Coronavírus (COVID-19) IgG/IgM (MedLevensohn, Brazil); COVID-19 IgG/IgM ECO Test (Ecodiagnóstica, Brazil); Camtech COVID-19 IgM/IgG Rapid Test Kit (Camtech Diagnostics Pte Ltd, Singapore); and one Step COVID-19 Test for total antibodies (Guangzhou Wondfo Biotech Co, China). Results. The four tests studied showed high diagnostic performance characteristics for the diagnoses of definite or probable SARS-CoV-2 infection. The best measures were for the Wondfo test: sensitivity (86.59%; 95%CI, 77.26-93.11%); specificity (100%; 90.51-100%); DOR (257; 60-1008); LR+ (33.43; 4.82-231.85); LR− (0.13; 0.08 - 0.23); accuracy (90.76%; 84.06- 95.29%); Matthews Correlation coefficient (MCC) 0.82. Although considering only the probable SARS-CoV-2 infection (PCR-) cases, all the kits studied showed limited values. Conclusion. Our data demonstrate the excellent performance of LFA for the diagnoses of definite or probable SARS-CoV-2 infection. There was substantial heterogeneity in sensitivities of IgM and IgG antibodies among the manufacturers. LFA tests cannot replace molecular diagnostics, but should be used as additional screening tool.


2020 ◽  
Vol 13 (9) ◽  
Author(s):  
Shahnaz Armin ◽  
Fereshteh Karbasian ◽  
Seyedeh Mahsan Hoseinialfatemi ◽  
Roxana Mansour Ghanaie ◽  
Sedigheh Rafiei Tabatabaei ◽  
...  

Background: In December 2019, a new coronavirus appeared in China, as a cause of acute respiratory disease. Healthcare Workers (HCWs) in children's hospitals are one of the groups who are at a high rate of exposure to COVID-19 patients. The detection of antibodies is useful and helps diagnose late or recent SARS-CoV-2 infection. Most children may present with asymptomatic or mild SARS-CoV-2 infection and can be silent sources of infection in the community and hospitals. Objectives: This study was conducted to determine the antibodies (IgM and IgG) against SARS-CoV-2 in Mofid children's hospital staff. Methods: This cross-sectional study evaluated 475 staff from Mofid children's hospital from April 20 to May 5, 2020, in Tehran. We collected blood samples for the antibody assay with a rapid test kit. A questionnaire was used to collect demographic and clinical data. Results: Of 475 staff who participated in this study, 25 (5.3%) were diagnosed with COVID-19 by Polymerase Chain Reaction (PCR) and/or CT scan. Besides, 140 (29.4%) of them were positive for IgM and/or IgG SARS-CoV-2 antibodies. Conclusions: The seropositivity of antibodies against SARS-CoV-2 among children's hospital staff was higher than expected. Approximately 5% of the participants were diagnosed as definitive positive COVID-19 cases by PCR and/or CT scan, but 29.4% of them were seropositive. The difference is a warning, as it shows seropositive people could be silent sources of transmission during asymptomatic infection.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Jobin Thomas ◽  
Ana Balseiro ◽  
Christian Gortázar ◽  
María A. Risalde

AbstractAnimal tuberculosis (TB) is a multi-host disease caused by members of the Mycobacterium tuberculosis complex (MTC). Due to its impact on economy, sanitary standards of milk and meat industry, public health and conservation, TB control is an actively ongoing research subject. Several wildlife species are involved in the maintenance and transmission of TB, so that new approaches to wildlife TB diagnosis have gained relevance in recent years. Diagnosis is a paramount step for screening, epidemiological investigation, as well as for ensuring the success of control strategies such as vaccination trials. This is the first review that systematically addresses data available for the diagnosis of TB in wildlife following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The article also gives an overview of the factors related to host, environment, sampling, and diagnostic techniques which can affect test performance. After three screenings, 124 articles were considered for systematic review. Literature indicates that post-mortem examination and culture are useful methods for disease surveillance, but immunological diagnostic tests based on cellular and humoral immune response detection are gaining importance in wildlife TB diagnosis. Among them, serological tests are especially useful in wildlife because they are relatively inexpensive and easy to perform, facilitate large-scale surveillance and can be used both ante- and post-mortem. Currently available studies assessed test performance mostly in cervids, European badgers, wild suids and wild bovids. Research to improve diagnostic tests for wildlife TB diagnosis is still needed in order to reach accurate, rapid and cost-effective diagnostic techniques adequate to a broad range of target species and consistent over space and time to allow proper disease monitoring.


2020 ◽  
Vol 41 (S1) ◽  
pp. s431-s432
Author(s):  
Rachael Snyders ◽  
Hilary Babcock ◽  
Christopher Blank

Background: Immunization resistance is fueling a resurgence of vaccine-preventable diseases in the United States, where several large measles outbreaks and 1,282 measles cases were reported in 2019. Concern about these measles outbreaks prompted a large healthcare organization to develop a preparedness plan to limit healthcare-associated transmission. Verification of employee rubeola immunity and immunization when necessary was prioritized because of transmission risk to nonimmune employees and role of the healthcare personnel in responding to measles cases. Methods: The organization employs ∼31,000 people in diverse settings. A multidisciplinary team was formed by infection prevention, infectious diseases, occupational health, and nursing departments to develop the preparedness plan. Immunity was monitored using a centralized database. Employees without evidence of immunity were asked to provide proof of vaccination, defined by the CDC as 2 appropriately timed doses of rubeola-containing vaccine, or laboratory confirmation of immunity. Employees were given 30 days to provide documentation or to obtain a titer at the organization’s expense. Staff with negative titers were given 2 weeks to coordinate with the occupational heath department for vaccination. Requests for medical or religious accommodations were evaluated by occupational heath staff, the occupational heath medical director, and the human resources department. All employees were included, though patient-interfacing employees in departments considered higher risk were prioritized. These areas were the emergency, dermatology, infectious diseases, labor and delivery, obstetrics, and pediatrics departments. Results: At the onset of the initiative in June 2019, 4,009 employees lacked evidence of immunity. As of November 2019, evidence of immunity had been obtained for 3,709 employees (92.5%): serological evidence of immunity was obtained for 2,856 (71.2%), vaccine was administered to 584 (14.6%), and evidence of previous vaccination was provided by 269 (6.7%). Evidence of immunity has not been documented for 300 (7.5%). The organization administered 3,626 serological tests and provided 997 vaccines, costing ∼$132,000. Disposition by serological testing is summarized in Table 1. Conclusions: A measles preparedness strategy should include proactive assessment of employees’ immune status. It is possible to expediently assess a large number of employees using a multidisciplinary team with access to a centralized database. Consideration may be given to prioritization of high-risk departments and patient-interfacing roles to manage workload.Funding: NoneDisclosures: None


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S150-S150
Author(s):  
Michael R Hovan ◽  
Vanessa Cedarbaum ◽  
Thomas Kirn ◽  
Thomas Kirn

Abstract Background Carbapenem-Resistant Enterobacteriales (CRE) bacteremia is associated with significant morbidity and mortality. CRE were assigned a threat level of “urgent” in the 2019 CDC report on antibiotic resistance in the United States. We attempted to identify predictors of 30-day mortality in patients with CRE bacteremia. Methods We performed a chart review of 146 patients with CRE bacteremia from January 2010 - July 2019. CRE was defined using the current CDC definition. Electronic medical records were reviewed to obtain clinical characteristics and outcomes including prior antibiotic use, comorbidities, prior location, treatment, hospital course, microbiological data and outcomes including in-hospital mortality. Results Of 146 patients included for analysis, the overall 30-day mortality rate was 36.3%. Patients admitted from a healthcare facility including outside hospitals, rehab, nursing homes, and LTACs had a 49.1% (29/59) 30-day mortality rate compared to 27.5% (24/87) for those admitted from home (RR=1.78, 95% CI 1.16–2.73, p=.0082). Patients with a Pitt bacteremia score ≥ 4 had a greater 30-day mortality rate (42.6%, 26/61) compared to those with a Pitt bacteremia score < 4 (17.6%, 15/85) (RR=2.92, 95% CI 1.40–4.16, p=.0015). Patients that received inactive empiric therapy had a 30-day mortality rate of 36% (36/100) compared to 36.9% (17/46) in those that received active empiric therapy (RR=.9741, 95% CI .6155-1.59, p=.9109). Patients with isolates determined to have a meropenem MIC ≥ 4 had a 30-day mortality rate of 40.2% (37/92) while those with an MIC < 4 had a 30-day mortality rate of 30.2% (16/53) (RR=1.33, 95% CI .8250–2.1513, p=.2408). A pulmonary source of bacteremia was associated with an increased risk of 30-day mortality (64.3%, 9/14) compared to all other sources of bacteremia (34.8%, 31/89) (RR=1.85, 95% CI 1.39–2.99, p=.0129). No other infection source was associated with an increased 30-day mortality rate. Conclusion Admission from a healthcare facility, Pitt bacteremia score ≥ 4, and pulmonary source of bacteremia were associated with increased risk of 30-day mortality. Interestingly, administration of active empiric therapy was not associated with a decreased mortality risk. Meropenem MIC was not predictive of 30-day mortality. Disclosures All Authors: No reported disclosures


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
David R. McIlwain ◽  
Han Chen ◽  
Maria Apkarian ◽  
Melton Affrime ◽  
Bonnie Bock ◽  
...  

Abstract Background Influenza places a significant burden on global health and economics. Individual case management and public health efforts to mitigate the spread of influenza are both strongly impacted by our ability to accurately and efficiently detect influenza viruses in clinical samples. Therefore, it is important to understand the performance characteristics of available assays to detect influenza in a variety of settings. We provide the first report of relative performance between two products marketed to streamline detection of influenza virus in the context of a highly controlled volunteer influenza challenge study. Methods Nasopharyngeal swab samples were collected during a controlled A/California/2009/H1N1 influenza challenge study and analyzed for detection of virus shedding using a validated qRT-PCR (qPCR) assay, a sample-to-answer qRT-PCR device (BioMerieux BioFire FilmArray RP), and an immunoassay based rapid test kit (Quidel QuickVue Influenza A + B Test). Results Relative to qPCR, the sensitivity and specificity of the BioFire assay was 72.1% [63.7–79.5%, 95% confidence interval (CI)] and 93.5% (89.3–96.4%, 95% CI) respectively. For the QuickVue rapid test the sensitivity was 8.5% (4.8–13.7%, 95% CI) and specificity was 99.2% (95.6–100%, 95% CI). Conclusion Relative to qPCR, the BioFire assay had superior performance compared to rapid test in the context of a controlled influenza challenge study.


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