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1.
BMC Infect Dis ; 21(1): 187, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602152

RESUMO

BACKGROUND: Thresholds for SARS-CoV-2 antibody assays have typically been determined using samples from symptomatic, often hospitalised, patients. In this setting the sensitivity and specificity of the best performing assays can both exceed 98%. However, antibody assay performance following mild infection is less clear. METHODS: We assessed quantitative IgG responses in a cohort of healthcare workers in Oxford, UK, with a high pre-test probability of Covid-19, in particular the 991/11,475(8.6%) who reported loss of smell/taste. We use anosmia/ageusia and other risk factors as probes for Covid-19 infection potentially undiagnosed by immunoassays by investigating their relationship with antibody readings either side of assay thresholds. RESULTS: The proportion of healthcare workers reporting anosmia/ageusia increased at antibody readings below diagnostic thresholds using an in-house ELISA (n = 9324) and the Abbott Architect chemiluminescent microparticle immunoassay (CMIA; n = 11,324): 426/906 (47%) reported anosmia/ageusia with a positive ELISA, 59/449 (13.1%) with high-negative and 326/7969 (4.1%) with low-negative readings. Similarly, by CMIA, 518/1093 (47.4%) with a positive result reported anosmia/ageusia, 106/686 (15.5%) with a high-negative and 358/9563 (3.7%) with a low-negative result. Adjusting for the proportion of staff reporting anosmia/ageusia suggests the sensitivity of both assays in mild infection is lower than previously reported: Oxford ELISA 89.8% (95%CI 86.6-92.8%) and Abbott CMIA 79.3% (75.9-82.7%). CONCLUSION: Following mild SARS-CoV-2 infection 10-30% of individuals may have negative immunoassay results. While lowered diagnostic thresholds may result in unacceptable specificity, our findings have implications for epidemiological analyses and result interpretation in individuals with a high pre-test probability. Samples from mild PCR-confirmed infections should be included in SARS-CoV-2 immunoassay evaluations.


Assuntos
Anticorpos Antivirais/análise , /diagnóstico , Imunoglobulina G/análise , Adulto , Ageusia/virologia , Infecções Assintomáticas , Ensaio de Imunoadsorção Enzimática/normas , Feminino , Pessoal de Saúde , Humanos , Imunoensaio/normas , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Doenças não Diagnosticadas , Reino Unido
2.
Mikrobiyol Bul ; 55(1): 17-29, 2021 Jan.
Artigo em Turco | MEDLINE | ID: mdl-33590978

RESUMO

Shortly after the first detection of human immundeficiency virus (HIV) infection in USA in 1981, the number of cases have increased gradually from all around the world. Turkey's high capacity for tourism and the unique geographic location extending between Europe and Asia, provides convenience for the passage of individuals across the countries and sexually transmitted infections including HIV, as well. According to the official data of the Ministry of Health; there are 25809 HIV positive and 1958 AIDS cases as of November 30, 2020, after the epidemic started in 1985 in Turkey. Despite the decrease in the number of newly detected HIV cases as a result of serious measures taken for the transmission of infection worldwide, the increase in the number of cases still continues in our country. Shortening the reporting period and starting treatment as soon as possible in the diagnosis of infection is critical for the control of the epidemic. For this purpose, Centers for Disease Control and Prevention (CDC) published a new test algorithm in 2010, which suggested the use of the Geenius™ HIV ½ supplemental assay test instead of western blot tests, which have been used for many years to verify HIV screening test positivity. In this study, we aimed to report the experience of the National HIV-Acquiner Immundeficiency Syndrome(AIDS) and Viral Hepatitis Reference Laboratories of Turkey in the first year of transition to the new HIV algorithm and to evaluate the diagnostic performance of Geenius™ HIV ó and line immunassay (LIA) s. A total of 2090 anti-HIV positive patient sera sent to National HIV-AIDS and Viral Hepatitis Reference Laboratories of Turkey, Ankara for HIV confirmation were included in the study. All samples were retested with a fourth-generation enzyme linked immunosorbent assay (ELISA) test (VIDAS® HIV-1/2 Duo Ultra assay, BioMerieux, France) followed by the confirmatory tests; Geenius™ HIV 1/2 confirmatory assay (BioRad, Redmond, WA) and Line-immunoassay (INNO-LIA HIV ½ Score, Fujirebio, reverse transcriptase polymerase chain reaction (RT-PCR) (artus HI Virus-1 RT-PCR, Qiagen, Germany) test and in-house HIV-2 RNA and proviral DNA PCR. The sensitivity, specificity, and the agreement of the each assay were compared. Cohen's Kappa analysis was used for the evaluation of the agreement between the tests. According to the new algorithm which recommended Geenius™ test besides HIV-1 RNA test, 1707 (81.7%) HIV-1 positive samples were identified. Of these samples; 95.9% and 95.02% were identified as HIV-1 positive by GeeniusTM and INNO-LIA, respectively. However, 2.5% of the positive samples were negative with Geenius™ and 3.5% with INNO-LIA. One and a half percentage (1.5%) of these samples were detected with Geenius™ and 1.4% with INNO-LIA as indeterminant. When all the positive samples determined with ELISA were evaluated; it was detected that,1.3% were indeterminate by Geenius™ test and 2.4% by the INNO-LIA test. When the INNO-LIA test was regarded as the gold standard method; sensitivity, specificity, positive predictive and negative predictive values of the Geenius™ test were as follows; 99.7%, 96.1%, 98.9%, and 99.1%. The agreement between INNO-LIA and Geenius™ tests was found to be 98.95% (κ= 0.969; very good). When the Geenius™ and HIV-1 PCR tests were evaluated together for the confirmation; the sensitivities of Geenius™ and INNO-LIA tests were 99.8% and 98.3%, specificities were 89.8% and 85.3%, respectively. Slight positive bands were detected in the gp36 or gp140 bands, the HIV-2 specific envelope proteins, were detected in seven samples, However, the positivity disappeared after the dilution of the samples and it was accepted as false positivite reaction due to the absence of HIV-2 RNA and proviral DNA in these samples. In conclusion; we concluded that Geenius ™ and INNO-LIA tests have a perfect agreement in HIV diagnosis and due to the rapid and reliable results provided for the HIV test protocol, Geenius™ test can be used safely as an alternative to the immunoblot tests. HIV-1 RNA testing must be performed in all HIV confirmation centers in order to detect acute HIV cases in the fast and early period which are the main reason for the updates in HIV diagnosis.


Assuntos
Algoritmos , Infecções por HIV , Imunoensaio , Anticorpos Anti-HIV/sangue , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , HIV-1/imunologia , HIV-2/imunologia , Humanos , Imunoensaio/normas , Sensibilidade e Especificidade , Turquia/epidemiologia
3.
Clin Oncol (R Coll Radiol) ; 33(1): e73-e81, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33350940

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic due to infection by a new human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has seriously disrupted the provision of oncology services and their uptake. Antibody testing, both at an individual level and of populations, has been widely viewed to be a key activity for guiding the options for treatment of high-risk individuals, as well as the implementation of safe control of infection measures. Ideally, the detection of a specific antibody should signify that all individuals tested have been infected by SARS-CoV-2 and that in the case of specific IgG that they are immune to further infection. This would enable SARS-CoV-2-infected individuals to be appropriately managed and healthcare workers shown to be immune to return to work where they would no longer pose a risk to their patients or be at risk themselves. Unfortunately, this is not the case for COVID-19, where it has been shown that immunity may not be protective, and seroconversion delayed or absent. The variability in antibody test performance, particularly that of lateral flow assays, has caused confusion for the public and healthcare professions alike. Many antibody test devices have been made available without independent evaluations and these may lack both adequate sensitivity and specificity. This review seeks to educate healthcare workers, particularly those working in oncology, of the current benefits and limitations of SARS-CoV-2 antibody testing.


Assuntos
/métodos , /imunologia , Imunoensaio/normas , Oncologistas , Humanos , Imunoensaio/métodos , Masculino , Saúde do Trabalhador/normas , Sensibilidade e Especificidade
4.
BMJ ; 371: m4262, 2020 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177070

RESUMO

OBJECTIVE: To assess the accuracy of the AbC-19 Rapid Test lateral flow immunoassay for the detection of previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. DESIGN: Test accuracy study. SETTING: Laboratory based evaluation. PARTICIPANTS: 2847 key workers (healthcare staff, fire and rescue officers, and police officers) in England in June 2020 (268 with a previous polymerase chain reaction (PCR) positive result (median 63 days previously), 2579 with unknown previous infection status); and 1995 pre-pandemic blood donors. MAIN OUTCOME MEASURES: AbC-19 sensitivity and specificity, estimated using known negative (pre-pandemic) and known positive (PCR confirmed) samples as reference standards and secondly using the Roche Elecsys anti-nucleoprotein assay, a highly sensitive laboratory immunoassay, as a reference standard in samples from key workers. RESULTS: Test result bands were often weak, with positive/negative discordance by three trained laboratory staff for 3.9% of devices. Using consensus readings, for known positive and negative samples sensitivity was 92.5% (95% confidence interval 88.8% to 95.1%) and specificity was 97.9% (97.2% to 98.4%). Using an immunoassay reference standard, sensitivity was 94.2% (90.7% to 96.5%) among PCR confirmed cases but 84.7% (80.6% to 88.1%) among other people with antibodies. This is consistent with AbC-19 being more sensitive when antibody concentrations are higher, as people with PCR confirmation tended to have more severe disease whereas only 62% (218/354) of seropositive participants had had symptoms. If 1 million key workers were tested with AbC-19 and 10% had actually been previously infected, 84 700 true positive and 18 900 false positive results would be projected. The probability that a positive result was correct would be 81.7% (76.8% to 85.8%). CONCLUSIONS: AbC-19 sensitivity was lower among unselected populations than among PCR confirmed cases of SARS-CoV-2, highlighting the scope for overestimation of assay performance in studies involving only PCR confirmed cases, owing to "spectrum bias." Assuming that 10% of the tested population have had SARS-CoV-2 infection, around one in five key workers testing positive with AbC-19 would be false positives. STUDY REGISTRATION: ISRCTN 56609224.


Assuntos
Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/diagnóstico , Imunoensaio/normas , Pneumonia Viral/diagnóstico , Betacoronavirus , Feminino , Bombeiros , Pessoal de Saúde , Humanos , Masculino , Pandemias , Polícia , Valor Preditivo dos Testes , Kit de Reagentes para Diagnóstico/normas , Sensibilidade e Especificidade , Reino Unido
5.
Emerg Microbes Infect ; 9(1): 2200-2211, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32962560

RESUMO

Serology detection is recognized for its sensitivity in convalescent patients with COVID-19, in comparison with nucleic acid amplification tests (NAATs). This article aimed to evaluate the diagnostic accuracy of serologic methods for COVID-19 based on assay design and post-symptom-onset intervals. Two authors independently searched PubMed, Cochrane library, Ovid, EBSCO for case-control, longitudinal and cohort studies that determined the diagnostic accuracy of serology tests in comparison with NAATs in COVID-19 cases and used QUADAS-2 for quality assessment. Pooled accuracy was analysed using INLA method. A total of 27 studies were included in this meta-analysis, with 4 cohort, 16 case-control and 7 longitudinal studies and 4565 participants. Serology tests had the lowest sensitivity at 0-7 days after symptom onset and the highest at >14 days. TAB had a better sensitivity than IgG or IgM only. Using combined nucleocapsid (N) and spike(S) protein had a better sensitivity compared to N or S protein only. Lateral flow immunoassay (LFIA) had a lower sensitivity than enzyme-linked immunoassay (ELISA) and chemiluminescent immunoassay (CLIA). Serology tests will play an important role in the clinical diagnosis for later stage COVID-19 patients. ELISA tests, detecting TAB or targeting combined N and S proteins had a higher diagnostic sensitivity compared to other methods.


Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Testes Sorológicos/métodos , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/imunologia , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Pandemias , Pneumonia Viral/imunologia , Viés de Publicação , Sensibilidade e Especificidade , Testes Sorológicos/normas , Avaliação de Sintomas
6.
Emerg Microbes Infect ; 9(1): 2157-2168, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32940547

RESUMO

This multicenter, retrospective study included 346 serum samples from 74 patients with coronavirus disease 2019 (COVID-19) and 194 serum samples from non-COVID-19 patients to evaluate the performance of five anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests, i.e. two chemiluminescence immunoassays (CLIAs): Roche Elecsys® Anti-SARS-CoV-2 Test (Roche Test) and Abbott SARS-CoV-2 IgG (Abbott Test), and three lateral flow immunoassays (LFIAs): Wondfo SARS-CoV-2 Antibody Test (Wondfo Test), ASK COVID-19 IgG/IgM Rapid Test (ASK Test), and Dynamiker 2019-nCoV IgG/IgM Rapid Test (Dynamiker Test). We found high diagnostic sensitivities (%, 95% confidence interval [CI]) for the Roche Test (97.4%, 93.4-99.0%), Abbott Test (94.0%, 89.1-96.8%), Wondfo Test (91.4%, 85.8-94.9%), ASK Test (97.4%, 93.4-99.0%), and Dynamiker Test (90.1%, 84.3-94.0%) after >21 days of symptom onset. Meanwhile, the diagnostic specificity was 99.0% (95% CI, 96.3-99.7%) for the Roche Test, 97.9% (95% CI, 94.8-99.2%) for the Abbott Test, and 100.0% (95% CI, 98.1-100.0%) for the three LFIAs. Cross-reactivity was observed in sera containing anti-cytomegalovirus (CMV) IgG/IgM antibodies and autoantibodies. No difference was observed in the time to seroconversion detection of the five serological tests. Specimens from patients with COVID-19 pneumonia demonstrated a shorter seroconversion time and higher chemiluminescent signal than those without pneumonia. Our data suggested that understanding the dynamic antibody response after COVID-19 infection and performance characteristics of different serological test are crucial for the appropriate interpretation of serological test result for the diagnosis and risk assessment of patient with COVID-19 infection.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Imunoensaio/métodos , Medições Luminescentes/métodos , Pneumonia Viral/diagnóstico , Pneumonia Viral/imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Reações Cruzadas/imunologia , Feminino , Humanos , Imunoensaio/normas , Medições Luminescentes/normas , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Reprodutibilidade dos Testes , Soroconversão , Testes Sorológicos , Índice de Gravidade de Doença , Taiwan/epidemiologia
7.
Hell J Nucl Med ; 23 Suppl: 8-14, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32860390

RESUMO

On December 2019, a new coronavirus disease (COVID-19) emerged in China and spread worldwide, causing acute severe respiratory syndrome. Due to the increased transmission rate of the virus, it became of great importance the early diagnosis of the disease. The coronavirus pandemic led to the development of numerous tests in order to mass screening population for active viral load and for the identification of antibodies for epidemiological purposes. This review summarizes the different diagnostic tests available to the clinicians for the diagnosis and follow up of the SARS COV-2 infections.


Assuntos
Infecções por Coronavirus/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Pneumonia Viral/diagnóstico , Radiografia Torácica/métodos , Técnicas de Cultura de Células/métodos , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico por imagem , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Técnicas de Diagnóstico Molecular/normas , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico por imagem , Radiografia Torácica/normas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Sensibilidade e Especificidade , Testes Sorológicos/métodos , Testes Sorológicos/normas
8.
Lab Med ; 51(5): e59-e65, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32657343

RESUMO

Clinical laboratory testing routinely provides actionable results, which help direct patient care in the inpatient and outpatient settings. Since December 2019, a novel coronavirus (SARS-CoV-2) has been causing disease (COVID-19 [coronavirus disease 2019]) in patients, beginning in China and now extending worldwide. In this context of a novel viral pandemic, clinical laboratories have developed multiple novel assays for SARS-CoV-2 diagnosis and for managing patients afflicted with this illness. These include molecular and serologic-based tests, some with point-of-care testing capabilities. Herein, we present an overview of the types of testing available for managing patients with COVID-19, as well as for screening of potential plasma donors who have recovered from COVID-19.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Técnicas de Diagnóstico Molecular/métodos , Pneumonia Viral/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Testes Sorológicos/métodos , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/sangue , Humanos , Imunoensaio/normas , Técnicas de Diagnóstico Molecular/normas , Pandemias , Pneumonia Viral/sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Sensibilidade e Especificidade , Testes Sorológicos/normas
9.
J Clin Microbiol ; 58(9)2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32636214

RESUMO

The clinical performances of six molecular diagnostic tests and a rapid antigen test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were clinically evaluated for the diagnosis of coronavirus disease 2019 (COVID-19) in self-collected saliva. Saliva samples from 103 patients with laboratory-confirmed COVID-19 (15 asymptomatic and 88 symptomatic) were collected on the day of hospital admission. SARS-CoV-2 RNA in saliva was detected using a quantitative reverse transcription-PCR (RT-qPCR) laboratory-developed test (LDT), a cobas SARS-CoV-2 high-throughput system, three direct RT-qPCR kits, and reverse transcription-loop-mediated isothermal amplification (RT-LAMP). The viral antigen was detected by a rapid antigen immunochromatographic assay. Of the 103 samples, viral RNA was detected in 50.5 to 81.6% of the specimens by molecular diagnostic tests, and an antigen was detected in 11.7% of the specimens by the rapid antigen test. Viral RNA was detected at significantly higher percentages (65.6 to 93.4%) in specimens collected within 9 days of symptom onset than in specimens collected after at least 10 days of symptoms (22.2 to 66.7%) and in specimens collected from asymptomatic patients (40.0 to 66.7%). Self-collected saliva is an alternative specimen option for diagnosing COVID-19. The RT-qPCR LDT, a cobas SARS-CoV-2 high-throughput system, direct RT-qPCR kits (except for one commercial kit), and RT-LAMP showed sufficient sensitivities in clinical use to be selectively used in clinical settings and facilities. The rapid antigen test alone is not recommended for an initial COVID-19 diagnosis because of its low sensitivity.


Assuntos
Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Imunoensaio , Técnicas de Amplificação de Ácido Nucleico , Pneumonia Viral/diagnóstico , Saliva/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos Virais/análise , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Técnicas de Laboratório Clínico/estatística & dados numéricos , Feminino , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Imunoensaio/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/normas , Técnicas de Amplificação de Ácido Nucleico/estatística & dados numéricos , Pandemias , RNA Viral/análise , RNA Viral/genética , Sensibilidade e Especificidade , Manejo de Espécimes , Adulto Jovem
10.
ACS Sens ; 5(8): 2283-2296, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32627534

RESUMO

The COVID-19 pandemic has created huge damage to society and brought panic around the world. Such panic can be ascribed to the seemingly deceptive features of COVID-19: Compared to other deadly viral outbreaks, it has medium transmission and mortality rates. As a result, the severity of the causative coronavirus, SARS-CoV-2, was deeply underestimated by society at the beginning of the COVID-19 outbreak. Based on this, in this review, we define the viruses with features similar to those of SARS-CoV-2 as the Panic Zone viruses. To contain those viruses, accurate and fast diagnosis followed by effective isolation and treatment of patients are pivotal at the early stage of virus breakouts. This is especially true when there is no cure or vaccine available for a transmissible disease, which is the case for the current COVID-19 pandemic. As of July 2020, more than 100 kits for COVID-19 diagnosis on the market have been surveyed in this review, while emerging sensing techniques for SARS-CoV-2 are also discussed. It is of critical importance to rationally use these kits for efficient management and control of the Panic Zone viruses. Therefore, we discuss guidelines to select diagnostic kits at different outbreak stages of the Panic Zone viruses, SARS-CoV-2 in particular. While it is of utmost importance to use nucleic acid based detection kits with low false negativity (high sensitivity) at the early stage of an outbreak, the low false positivity (high specificity) gains importance at later stages of the outbreak. When society is set to reopen from the lockdown stage of the COVID-19 pandemic, it becomes critical to have immunoassay based kits with high specificity to identify people who can safely return to society after their recovery from SARS-CoV-2 infections. Finally, since a massive attack from a viral pandemic requires a massive defense from the whole society, we urge both government and the private sector to research and develop affordable and reliable point-of-care testing (POCT) kits, which can be used massively by the general public (and therefore called massive POCT) to contain Panic Zone viruses in the future.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Kit de Reagentes para Diagnóstico/normas , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Pandemias , Testes Imediatos
11.
Clin Microbiol Infect ; 26(10): 1386-1394, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32603801

RESUMO

OBJECTIVES: To validate the diagnostic accuracy of a Euroimmun SARS-CoV-2 IgG and IgA immunoassay for COVID-19. METHODS: In this unmatched (1:2) case-control validation study, we used sera of 181 laboratory-confirmed SARS-CoV-2 cases and 326 controls collected before SARS-CoV-2 emergence. Diagnostic accuracy of the immunoassay was assessed against a whole spike protein-based recombinant immunofluorescence assay (rIFA) by receiver operating characteristic (ROC) analyses. Discrepant cases between ELISA and rIFA were further tested by pseudo-neutralization assay. RESULTS: COVID-19 patients were more likely to be male and older than controls, and 50.3% were hospitalized. ROC curve analyses indicated that IgG and IgA had high diagnostic accuracies with AUCs of 0.990 (95% Confidence Interval [95%CI]: 0.983-0.996) and 0.978 (95%CI: 0.967-0.989), respectively. IgG assays outperformed IgA assays (p=0.01). Taking an assessed 15% inter-assay imprecision into account, an optimized IgG ratio cut-off > 2.5 displayed a 100% specificity (95%CI: 99-100) and a 100% positive predictive value (95%CI: 96-100). A 0.8 cut-off displayed a 94% sensitivity (95%CI: 88-97) and a 97% negative predictive value (95%CI: 95-99). Substituting the upper threshold for the manufacturer's, improved assay performance, leaving 8.9% of IgG ratios indeterminate between 0.8-2.5. CONCLUSIONS: The Euroimmun assay displays a nearly optimal diagnostic accuracy using IgG against SARS-CoV-2 in patient samples, with no obvious gains from IgA serology. The optimized cut-offs are fit for rule-in and rule-out purposes, allowing determination of whether individuals in our study population have been exposed to SARS-CoV-2 or not. IgG serology should however not be considered as a surrogate of protection at this stage.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Imunoensaio/normas , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Pneumonia Viral/diagnóstico , Adulto , Área Sob a Curva , Estudos de Casos e Controles , Criança , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/virologia , Feminino , Humanos , Soros Imunes/química , Masculino , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/fisiopatologia , Pneumonia Viral/virologia , Curva ROC , Sensibilidade e Especificidade , Índice de Gravidade de Doença
12.
PLoS One ; 15(7): e0235234, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645006

RESUMO

BACKGROUND: Due to a lack of reliable reference intervals (RIs) for Kenya, we set out to determine RIs for 40 common chemistry and immunoassay tests as part of the IFCC global RI project. METHODS: Apparently healthy adults aged 18-65 years were recruited according to a harmonized protocol and samples analyzed using Beckman-Coulter analyzers. Value assigned serum panels were measured to standardize chemistry results. The need for partitioning reference values by sex and age was based on between-subgroup differences expressed as standard deviation ratio (SDR) or bias in lower or upper limits (LLs and ULs) of the RI. RIs were derived using a parametric method with/without latent abnormal value exclusion (LAVE). RESULTS: Sex-specific RIs were required for uric acid, creatinine, total bilirubin (TBil), total cholesterol (TC), ALT, AST, CK, GGT, transferrin, transferrin saturation (TfSat) and immunoglobulin-M. Age-specific RIs were required for glucose and triglyceride for both sexes, and for urea, magnesium, TC, HDL-cholesterol ratio, ALP, and ferritin for females. LAVE was effective in optimizing RIs for AST, ALT, GGT iron-markers and CRP by reducing influence of latent anemia and metabolic diseases. Thyroid profile RIs were derived after excluding volunteers with anti-thyroid antibodies. Kenyan RIs were comparable to those of other countries participating in the global study with a few exceptions such as higher ULs for TBil and CRP. CONCLUSIONS: Kenyan RIs for major analytes were established using harmonized protocol from well-defined reference individuals. Standardized RIs for chemistry analytes can be shared across sub-Saharan African laboratories with similar ethnic and life-style profile.


Assuntos
Variação Biológica da População , Análise Química do Sangue/normas , Imunoensaio/normas , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Análise Química do Sangue/estatística & dados numéricos , Interpretação Estatística de Dados , Feminino , Voluntários Saudáveis , Humanos , Imunoensaio/estatística & dados numéricos , Quênia , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Valores de Referência , Fatores Sexuais , Adulto Jovem
13.
Clin Chim Acta ; 509: 18-21, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32485155

RESUMO

BACKGROUND: Here, we report on a head-to-head comparison of the fully-automated Elecsys® Anti-SARS-CoV-2 immunoassay with the EDITM enzyme linked immunosorbent assays (ELISA) for the detection of SARS-CoV-2 antibodies in human plasma. METHODS: SARS-CoV-2 antibodies were measured with the Elecsys® assay and the EDITM ELISAs (IgM and IgG) in 64 SARS-CoV-2 RT-PCR confirmed COVID-19 patients with serial blood samples (n = 104) collected at different time points from symptom onset. Blood samples from 200 healthy blood donors and 256 intensive care unit (ICU) patients collected before the COVID-19 outbreak were also used. RESULTS: In COVID-19 patients, the percentage of positive results rose with time from symptom onset, peaking to positivity rates after 15-22 days of 100% for the Elecsys® assay, of 94% for the EDITM IgM-ELISA and of 100% for the EDITM IgG ELISA. In the 104 blood samples, the agreement between positive/negative classifications of the Elecsys® assay and the EDITM ELISAs (IgM or IgG) was 90%. The false positivity rates in the healthy blood donors and the ICU patients were < 1% for the Elecsys® assay and < 3% for the EDITM ELISAs. CONCLUSIONS: Our results indicate a high sensitivity and specificity for the Elecsys® assay and an acceptable agreement with the EDITM ELISAs.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico , Betacoronavirus/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Feminino , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Masculino , Pandemias , Testes Sorológicos/métodos , Testes Sorológicos/normas
15.
PLoS One ; 15(5): e0231217, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32374728

RESUMO

During influenza epidemics, Japanese clinicians routinely perform rapid influenza diagnostic tests (RIDTs) in the examination of patients who have an influenza-like illness, and patients with positive test results, including otherwise healthy individuals, are treated with anti-influenza drugs. However, it was recently reported that the sensitivity of RIDTs was extremely low in adult patients. We examined the sensitivity and specificity of an RIDT that is widely used in Japan, ImunoAce Flu (TAUNS, Shizuoka, Japan), in comparison to reverse transcriptase polymerase chain reaction (RT-PCR). The sensitivity and specificity of the ImunoAce Flu test were 97.1% (95%CI: 93.8-98.9) and 89.2% (95%CI: 84.1-93.1), respectively. The ImunoAce Flu test is designed to not only detect influenza A or B, but also to detect H1N1pdm09 with the use of an additional test kit (Linjudge FluA/pdm). Its sensitivity and specificity for A/H1N1pdm09 were 97.6% (95%CI: 87.4-99.9) and 92.6% (95%CI: 82.1-97.9), respectively. Thus, by consecutively testing patients with the ImunoAce Flu test followed by the Linjudge FluA/pdm test, we are able to diagnose whether a patient has A/H1N1pdm09 or A/H3N2 infection within a short time. The reliability of rapid test results seems to be much higher in Japan than in other countries, because approximately 90% of influenza patients are tested and treated within 48 hours after the onset of illness, when the influenza viral load in the upper respiratory tract is high. From the Japanese experience, RIDTs are sufficiently sensitive and highly useful, if patients are tested within 48 hours after the onset of illness.


Assuntos
Testes Diagnósticos de Rotina , Influenza Humana/diagnóstico , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Testes Diagnósticos de Rotina/métodos , Testes Diagnósticos de Rotina/normas , Feminino , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Influenza Humana/sangue , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Japão , Masculino , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Fatores de Tempo
16.
J Infect Dis ; 222(3): 362-366, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32473021

RESUMO

We comparatively assessed sensitivities and specificities of 4 commercial enzyme-linked immunosorbent assays (ELISAs) and 2 rapid tests in 77 patients with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 infection, grouped by interval since symptom onset. Although test sensitivities were low (<40%) within the first 5 days after disease onset, immunoglobulin (Ig) M, IgA, and total antibody ELISAs increased in sensitivity to >80% between days 6 and 10 after symptom onset. The evaluated tests (including IgG and rapid tests) provided positive results in all patients at or after the 11th day after onset of disease. The specificities of the ELISAs were 83% (IgA), 98% (IgG), and 97% (IgM and total antibody).


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Ensaio de Imunoadsorção Enzimática/normas , Imunoensaio/métodos , Pneumonia Viral/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Betacoronavirus/genética , Infecções por Coronavirus/imunologia , Feminino , Humanos , Imunoensaio/normas , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Pandemias , Pneumonia Viral/imunologia , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Fatores de Tempo , Adulto Jovem
17.
Sci Rep ; 10(1): 8543, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444793

RESUMO

Brucella is alpha-2 Proteobacteria mainly responsible for multi-factorial bacterial zoonotic disease brucellosis with low concentration (10-100 CFU) required to establish the infection. In this study, we developed sandwich ELISA with detection range of 102 to 108 cells mL-1 and limit of detection at 103 cells mL-1 by employing polyclonal rabbit IgG (capture antibody, 10 µg mL-1) and mice IgG (detection antibody, 50 µg mL-1) antibody for its detection. Surface Plasmon Resonance evaluated the interaction of detection antibody with whole cell spiked serum samples at LOD of 102 cells mL-1 along with non co-operative interaction of protein albumin. Further, kinetic evaluation study using detection antibody against cell envelope antigen was performed whereby, Equilibrium Dissociation Constant (KD) and Maximum Binding Capacity (Bmax) were found to be 16.48 pM and 81.67 m° for Brucella abortus S99 and 0.42 pM and 54.50 m° for Brucella melitensis 16 M, respectively. During interference study, sandwich ELISA assay cross-reacted with either of the polyclonal antibody of above Brucella species. Upon validation, no cross-reactivity observed with bacteria-closely related to Brucella. In conclusion, developed semi-quantitative sandwich immunoassay is sensitively rapid in whole cell detection of Brucella and will be useful in development of detection assays from environmental and clinical matrices.


Assuntos
Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Brucella abortus/isolamento & purificação , Brucella melitensis/isolamento & purificação , Brucelose/diagnóstico , Imunoensaio/normas , Animais , Anticorpos Antibacterianos/sangue , Brucella abortus/imunologia , Brucella melitensis/imunologia , Brucelose/imunologia , Brucelose/microbiologia , Feminino , Testes Imunológicos , Camundongos , Camundongos Endogâmicos BALB C , Coelhos
18.
Am J Trop Med Hyg ; 102(6): 1189-1190, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32329432

RESUMO

Public health measures are needed to resolve the novel coronavirus disease (COVID-19) pandemic, although a looming economic fallout merits close attention. Early safe reintroduction of immune individuals into the workforce may be essential to protecting the economic welfare of communities. Reverse transcriptase-polymerase chain reaction testing, our primary diagnostic tool to date, has sensitivity and timing concerns, owing to sampling/handling errors, as well as a complex virus-host interaction. Reverse transcriptase-polymerase chain reaction assays do not establish immune status once the virus has been cleared. Targeted serosurveillance for the determination of individuals' potential for transmissibility, particularly if paired with direct pathogen testing, may aid in "cleared for business" decision-making.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/patogenicidade , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , RNA Viral/genética , Betacoronavirus/genética , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Humoral , Imunoensaio/normas , Vigilância Imunológica , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Quarentena/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Estados Unidos/epidemiologia
20.
PLoS One ; 15(4): e0231358, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32310983

RESUMO

BACKGROUND: Malaria data reported through Mozambique's routine health information system are used to guide the implementation of prevention and control activities. Although previous studies have identified issues with the quality of aggregated data reported from public health facilities in the country, no studies have evaluated the quality of routine indicators recorded in health facility registries. This study addresses this issue by comparing indicators calculated from data from exit interviews and re-examinations of patients with data based on registry records from health facilities in order to measure the quality of registry data and data reporting in three provinces in Mozambique. METHODS: Data were collected from 1,840 outpatients from 117 health facilities in Maputo, Zambézia, and Cabo Delgado Provinces interviewed and examined as part of a malaria-specific health facility survey. Key indicators based on exit interview / re-examination data were compared to the same indicators based on records from health facility registries. Multivariable regression was performed to identify factors associated with indicators matching in re-examination / exit interview data and health facility registries. Aggregated indicators abstracted from facility registries were compared to those reported through the routine health management information system (HMIS) for the same time period. RESULTS: Sensitivity of exit interview / re-examination data compared with those recorded in facility registries was low for all indicators in all facilities. The lowest sensitivities were in Maputo, where the sensitivity for recording negative RDT results was 9.7%. The highest sensitivity was for recording positive RDT results in Cabo Delgado, at 75%. Multivariable analysis of factors associated with agreement between gold standard and registry data showed patients were less likely to be asked about having a fever in the triage ward in Maputo and Cabo Delgado (adjusted Odds Ratio 0.75 and 0.39 respectively), and in the outpatient ward in Cabo Delgado (aOR = 0.37), compared with the emergency department. Patients with positive RDT were also more likely to have RDT results recorded in all three provinces when patients had been managed according to national treatment guidelines during initial examination. Comparison of retrospective data abstracted from facility registries to HMIS data showed discrepancies in all three provinces. The proportion of outpatient cases with suspected and confirmed malaria were similar in registry and HMIS data across all provinces (a relatively low difference between registry and HMIS data of 3% in Maputo and Zambézia), though the total number of all-cause outpatient cases was consistently higher in the HMIS. The largest difference was in Maputo, where a total of 87,992 all-cause outpatient cases were reported in HMIS, compared with a total of 42,431 abstracted from facility registries. CONCLUSION: This study shows that care should be taken in interpreting trends based solely on routine data due to data quality issues, though the discrepancy in all-cause outpatient cases may be indicative that register availability and storage are important factors. As such, simple steps such as providing consistent access and storage of registers that include reporting of patient fever symptoms might improve the quality of routine data recorded at health facilities.


Assuntos
Testes Diagnósticos de Rotina/normas , Malária/diagnóstico , Estudos Transversais , Coleta de Dados , Testes Diagnósticos de Rotina/métodos , Febre/etiologia , Instalações de Saúde , Pessoal de Saúde/psicologia , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Entrevistas como Assunto , Malária/parasitologia , Malária/patologia , Moçambique , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/análise , Sistema de Registros , Estudos Retrospectivos
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