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1.
J Med Virol ; 94(1): 222-228, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34449894

RESUMO

The current study aimed at characterizing the dynamics of SARS-CoV-2 nucleocapsid (N) antigenemia in a cohort of critically ill adult COVID-19 patients and assessing its potential association with plasma levels of biomarkers of clinical severity and mortality. Seventy-three consecutive critically ill COVID-19 patients (median age, 65 years) were recruited. Serial plasma (n = 340) specimens were collected. A lateral flow immunochromatography assay and reverse-transcription polymerase chain reaction (RT-PCR) were used for SARS-CoV-2 N protein detection and RNA quantitation and in plasma, respectively. Serum levels of inflammatory and tissue-damage biomarkers in paired specimens were measured. SARS-CoV-RNA N-antigenemia and viral RNAemia were documented in 40.1% and 35.6% of patients, respectively at a median of 9 days since symptoms onset. The level of agreement between the qualitative results returned by the N-antigenemia assay and plasma RT-PCR was moderate (k = 0.57; p < 0.0001). A trend towards higher SARS-CoV-2 RNA loads was seen in plasma specimens testing positive for N-antigenemia assay than in those yielding negative results (p = 0.083). SARS-CoV-2 RNA load in tracheal aspirates was significantly higher (p < 0.001) in the presence of concomitant N-antigenemia than in its absence. Significantly higher serum levels of ferritin, lactose dehydrogenase, C-reactive protein, and D-dimer were quantified in paired plasma SARS-CoV-2 N-positive specimens than in those testing negative. Occurrence of SARS-CoV-2 N-antigenemia was not associated with increased mortality in univariate logistic regression analysis (odds ratio, 1.29; 95% confidence interval, 0.49-3.34; p = 0.59). In conclusion, SARS-CoV-2 N-antigenemia detection is relatively common in ICU patients and appears to associate with increased serum levels of inflammation and tissue-damage markers. Whether this virological parameter may behave as a biomarker of poor clinical outcome awaits further investigations.


Assuntos
COVID-19/virologia , Proteínas do Nucleocapsídeo de Coronavírus/sangue , Estado Terminal , SARS-CoV-2 , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos Virais/sangue , Biomarcadores/análise , Biomarcadores/sangue , COVID-19/mortalidade , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Feminino , Humanos , Inflamação , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/sangue , Fosfoproteínas/imunologia , Estudos Prospectivos , RNA Viral/análise , RNA Viral/sangue , SARS-CoV-2/genética , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Traqueia/virologia , Adulto Jovem
5.
Clin Microbiol Infect ; 27(4): 636.e1-636.e4, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33421573

RESUMO

OBJECTIVES: There is limited information on the performance of rapid antigen detection (RAD) tests to identify SARS-CoV-2-infected asymptomatic individuals. In this field study, we evaluated the Panbio™ COVID-19 Ag Rapid Test Device (Abbott Diagnostics, Jena, Germany) for this purpose. METHODS: A total of 634 individuals (355 female; median age, 37 years; range, 9-87) were enrolled. Two nasopharyngeal swabs were collected from household (n = 338) and non-household contacts (n = 296) of COVID-19 cases. RAD testing was carried out at the point of care. The RT-PCR test used was the TaqPath COVID-19 Combo Kit (Thermo Fisher Scientific, MA, USA). RESULTS: Household contacts were tested at a median of 2 days (range, 1-7) after diagnosis of the index case, whereas non-household contacts (n = 296) were tested at a median of 6 days (range, 1-7) after exposure. In total, 79 individuals (12.4%) tested positive by RT-PCR, of whom 38 (48.1%) yielded positive RAD results. The overall sensitivity and specificity of the RAD test was 48.1% (95% CI 37.4-58.9) and 100% (95% CI 99.3-100), respectively. Sensitivity was higher in household (50.8%; 95% CI 38.9-62.5) than in non-household (35.7%; 95% CI 16.3-61.2%) contacts. Individuals testing positive by RAD test were more likely (p < 0.001) to become symptomatic than their negative counterparts. DISCUSSION: The Panbio test displays low sensitivity in asymptomatic close contacts of COVID-19 patients, particularly in non-household contacts. Nonetheless, establishing the optimal timing for upper respiratory tract collection in this group seems imperative to pinpoint test sensitivity.


Assuntos
Infecções Assintomáticas , Teste para COVID-19/métodos , COVID-19/diagnóstico , Testes Imunológicos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos Virais/análise , Teste de Ácido Nucleico para COVID-19 , Criança , Busca de Comunicante , Características da Família , Feminino , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , Sistemas Automatizados de Assistência Junto ao Leito , SARS-CoV-2/imunologia , Sensibilidade e Especificidade , Adulto Jovem
6.
Clin Microbiol Infect ; 27(3): 472.e7-472.e10, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33189872

RESUMO

OBJECTIVES: To our knowledge no previous study has assessed the performance of a rapid antigen diagnostic immunoassay (RAD) conducted at the point of care (POC). We evaluated the Panbio™ COVID-19 Ag Rapid Test Device for diagnosis of coronavirus 2019 disease (COVID-19) in symptomatic patients (n = 412) attending primary healthcare centres. METHODS: RAD was performed immediately after sampling following the manufacturer's instructions (reading at 15 min). RT-PCRs were carried out within 24 h of specimen collection. Samples displaying discordant results were processed for culture in Vero E6 cells. Presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in cell cultures was confirmed by RT-PCR. RESULTS: Out of 412 patients, 43 (10.4%) tested positive by RT-PCR and RAD, and 358 (86.9%) tested negative by both methods; discordant results (RT-PCR+/RAD-) were obtained in 11 patients (2.7%). Overall specificity and sensitivity of rapid antigen detection (RAD) was 100% (95%CI 98.7-100%) and 79.6% (95%CI 67.0-88.8%), respectively, taking RT-PCR as the reference. Overall RAD negative predictive value for an estimated prevalence of 5% and 10% was 99% (95%CI 97.4-99.6%) and 97.9% (95%CI 95.9-98.9), respectively. SARS-CoV-2 could not be cultured from specimens yielding RT-PCR+/RAD- results (n = 11). CONCLUSION: The Panbio™ COVID-19 Ag Rapid Test Device performed well as a POC test for early diagnosis of COVID-19 in primary healthcare centres. More crucially, the data suggested that patients with RT-PCR-proven COVID-19 testing negative by RAD are unlikely to be infectious.


Assuntos
Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Testes Imediatos , SARS-CoV-2/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial , Antígenos Virais/análise , Teste de Ácido Nucleico para COVID-19 , Criança , Pré-Escolar , Diagnóstico Precoce , Feminino , Humanos , Imunoensaio , Lactente , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Kit de Reagentes para Diagnóstico , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Sensibilidade e Especificidade , Adulto Jovem
7.
Diagn Microbiol Infect Dis ; 84(3): 212-4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26658312

RESUMO

The performance of the Abbott Real Time MTB assay for detection of Mycobacterium tuberculosis complex in respiratory specimens was evaluated using a standard culture as the reference. The overall concordance between both methods was 0.95. The assay displayed an excellent sensitivity (100% for smear-positive/92.3% for smear-negative specimens) and specificity (100%).


Assuntos
Mycobacterium tuberculosis/genética , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Kit de Reagentes para Diagnóstico/normas , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
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