Background/aim: Traditional methods for detection of mycobacteria, such as microscopic examination for the presence of acid-fast bacilli and isolation of the organism by culture, have either a low sensitivity and/or specificity, or take weeks before a definite result is available. Molecular methods, especially those based on nucleic acid amplification, are rapid diagnostic methods which combine high sensitivity and high specificity. The aim of this study was to determine the usefulness of the Cobas Amplicor Mycobacterium tuberculosis polymerase chain reaction (CA-PCR) assay in detecting the tuberculosis cause in respiratory and nonrespiratory specimens (compared to culture).
Methods: Specimens were decontaminated by the N-acetyl-L-cystein-NaOH method. A 500 microL aliquot of the processed specimen were used for inoculation of Löwenstein-Jensen (L-J) slants, a drop for acid-fast staining, and 100 microL for PCR. The Cobas Amplicor PCR was performed according to the manufacturer's instructions.
Results: A total of 110 respiratory and 355 nonrespiratory specimens were investigated. After resolving discrepancies by reviewing medical history, overall sensitivity, specificity, and positive and negative predictive values for CA-PCR assay compared to culture, were 83%, 100%, 100%, and 96.8%, respectively. In comparison, they were 50%, 99.7%, 87.5%, and 98%, respectively, for the nonrespiratory specimens. The inhibition rate was 2.8% for respiratory, and 7.6% for nonrespiratory specimens.
Conclusion: CA-PCR is a reliable assay that enables specialists to start treatment promptly on a positive test result. Lower value for specificity in a group of nonrespiratory specimens is a consequence of an extremely small number of mycobacteria in some of them.
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http://dx.doi.org/10.2298/vsp0912992l | DOI Listing |
J Infect Dis
November 2024
Centers for Disease Control and Prevention, Atlanta, Georgia, United States.
Asymptomatic influenza virus infection occurs but may vary by factors such as age, vaccination status, or season. We examined the frequency of influenza virus infection and symptoms using data from two case-ascertained household transmission studies (2017-2023) with prospective, systematic collection of respiratory specimens and symptoms. From the 426 influenza virus infected household contacts that met our inclusion criteria, 8% were asymptomatic, 6% had non-respiratory symptoms, 23% had acute respiratory symptoms, and 62% had influenza-like illness symptoms.
View Article and Find Full Text PDFAsymptomatic influenza virus infection occurs but may vary by factors such as age, influenza vaccination status, or influenza season. We examined the frequency of influenza virus infection and associated symptoms using data from two case-ascertained household transmission studies (conducted from 2017-2023) with prospective, systematic collection of respiratory specimens and symptoms. From the 426 influenza virus infected household contacts that met our inclusion criteria, 8% were asymptomatic, 6% had non-respiratory symptoms, 23% had acute respiratory symptoms, and 62% had influenza-like illness symptoms.
View Article and Find Full Text PDFIndian Pediatr
September 2024
Department of Pediatric Intensive Care, Institute of Child Health and Hospital for Children, Madras Medical College, Chennai, Tamil Nadu, India. Correspondence to: Dr. Seenivasan Subramani, Department of Pediatric Intensive Care, Institute of Child Health and Hospital for Children, Madras Medical College, Chennai, Tamil Nadu, India.
Objective: To describe the clinical profile and determine the factors affecting mortality of children admitted with adenovirus infection in a tertiary care centre in South India.
Methods: In this observational study, respiratory specimens (nasopharyngeal swab / endotracheal aspirate) were collected from all hospitalized pediatric patients presenting with fever, cough, breathlessness, gastrointestinal symptoms, unexplained encephalopathy or multisystem involvement, between February 2023 and August 2023. Infection with adenovirus was determined by viral pathogen panel based on polymerase chain reaction (PCR) technique.
Int J Infect Dis
October 2024
Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, Big Data Institute Building, Roosevelt Drive, University of Oxford, Oxford, UK; Health Data Research UK Oxford, University of Oxford, Oxford, UK.
Background: Infectious diseases remain a major global health concern, including in China, with an estimated >10 million cases of infectious disease in 2019. We describe the burden of site-specific infectious diseases among Chinese adults.
Methods: From 2004 to 2008, the prospective China Kadoorie Biobank enrolled 512,726 adults aged 30-79 years from 10 diverse areas (5 rural, 5 urban) of China.
Lab Med
November 2024
Department of Pathology and Medicine, The University of Chicago, Chicago, IL, US.
We report a fatal case of Legionella feeleii endocarditis in a post-lung transplant patient. The diagnosis was delayed, as routine microbiological testing of nonrespiratory specimens does not account for extrapulmonary Legionella, and urine antigen testing only reliably detects Legionella pneumophila serogroup 1. This case also illustrates the utility of molecular sequencing for blood culture-negative endocarditis.
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