ABSTRACT
Desde sua identificação na China em dezembro de 2019, o novo coronavírus responsável pela COVID-19 evoluiu rapidamente para uma pandemia. A COVID-19 se manifesta com sintomas respiratórios inespecíficos de gravidade variável e pode exigir suporte respiratório avançado. Atualmente, o diagnóstico de COVID- 19 é confirmado por testes laboratoriais através da identificação de RNA viral na reação em cadeia da polimerase com transcriptase reversa (RT-PCR). Os exames de imagem de tórax foram considerados como parte da investigação diagnóstica de pacientes com suspeita ou probabilidade de COVID-19, nos lugares em que a RT-PCR não está disponível ou em que os resultados demoram ou são inicialmente negativos na presença de sintomas sugestivos de COVID-19. Os exames de imagem também foram considerados na complementação da avaliação clínica e dos parâmetros laboratoriais no tratamento de pacientes já diagnosticados com COVID-19. Antes de iniciar o desenvolvimento deste guia, vários estados-membros solicitaram um parecer da OMS sobre o papel dos exames de imagem do tórax em pacientes com suspeita ou confirmação de COVID-19. Uma revisão das práticas de exames de imagem em pacientes com suspeita ou confirmação de COVID-19 em todo o mundo encontrou grandes variações. Isso motivou o desenvolvimento de diretrizes globais sobre o uso de exames de imagem de tórax para apoiar os estados membros na resposta à pandemia da COVID-19. Este guia de aconselhamento rápido examina as evidências e faz recomendações para o uso de exames de imagem do tórax em pacientes agudos com suspeita, probabilidade ou confirmação de COVID-19, incluindo radiografia de tórax, tomografia computadorizada (TC) e ultrassonografia pulmonar. Destina-se a ser um guia prático para os profissionais de saúde envolvidos na evolução da atenção à COVID-19, desde o momento de chegada a um estabelecimento de saúde até a alta hospitalar. A orientação é relevante para pacientes com diferentes níveis de gravidade da doença, desde indivíduos assintomáticos a pacientes críticos...
Subject(s)
Humans , Pneumonia, Viral/diagnostic imaging , Thorax/diagnostic imaging , Coronavirus Infections/diagnostic imaging , RNA, Viral/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction/standards , Betacoronavirus/isolation & purificationABSTRACT
Background: Infectious Pancreatic Necrosis Virus (IPNV) is the etiological agent of a highly contagious disease that affects salmonids. In Chile, the second worldwide salmon producer, IPNV causes great economic loss and is one of the most frequently detected pathogens. Due to its high level of persistence and the lack of information about the efficiency of its diagnostic techniques, the National Reference Laboratory (NRL) for IPNV in Chile performed the first inter-laboratory ring trial, to evaluate the sensitivity, specificity and repeatability of the qRT-PCR detection methods used in the country. Results: Results showed 100% in sensitivity and specificity in most of the laboratories. Only three of the twelve participant laboratories presented problems in sensitivity and one in specificity. Problems in specificity (false positives) were most likely caused by cross contamination of the samples, while errors in sensitivity (false negatives) were due to detection problems of the least concentrated viral sample. Regarding repeatability, many of the laboratories presented great dispersion of the results (Ct values) for replicate samples over the three days of the trial. Moreover, large differences in the Ct values for each sample were detected among all the laboratories. Conclusions: Overall, the ring trial showed high values of sensitivity and specificity, with some problems of repeatability and inter-laboratory variability. This last issue needs to be addressed in order to allow harmonized diagnostic of IPNV within the country. We recommend the use of the NRL methods as validated and reliable qRT-PCR protocols for the detection of IPNV.
Subject(s)
Animals , Salmonidae/virology , Infectious pancreatic necrosis virus/isolation & purification , Birnaviridae Infections/diagnosis , Reverse Transcriptase Polymerase Chain Reaction/standards , Real-Time Polymerase Chain Reaction/standards , Fish Diseases/diagnosis , RNA, Viral/genetics , Observer Variation , Chile , Sensitivity and Specificity , Infectious pancreatic necrosis virus/genetics , Birnaviridae Infections/virology , Aquaculture , False Negative Reactions , False Positive Reactions , Fish Diseases/virology , LaboratoriesSubject(s)
Adult , Humans , Respiratory Syncytial Virus Infections , Respiratory Syncytial Virus, Human , Respiratory Syncytial Virus Infections/diagnosis , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , Respiratory Syncytial Virus, Human/immunology , Respiratory Syncytial Virus, Human/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/standards , Sensitivity and SpecificityABSTRACT
Viral load testing of human immunodeficiency virus (HIV) is an essential tool for initiating and monitoring the antiretroviral therapy for HIV patients. To this end, several methods including polymerase chain reaction (PCR), branched DNA (bDNA), nucleic acid sequence based amplification assay (NASBA) and internally controlled virion PCR (ICV PCR) have become available. Of these methods, the standard reverse transcription-PCR (RT-PCR) assay has been widely used in Korea. However, no comparison study has been performed among the various detection methods currently used in Korean patients. We evaluated the correlation and agreement between the PCR and the branched DNA (bDNA) assay for measurement of HIV RNA in Korean patients. Eighty randomly selected samples from HIV-1-seropositive patients visiting Yonsei Medical Center Severance Hospital were studied. We found that these assays show good agreement, have a reliable correlation (r = 0.92, mean difference in log10 copies/ mL +/- 2 standard deviation = 0.098 +/- 0.805) and produce values whose relationship is given by the following equation: log10v3 bDNA = -0.3405 + 1.0601 x log10RT-PCR. Thus, we conclude that these two methods may allow direct comparison of the results obtained from different assay systems.