24 research outputs found

    \u3cem\u3eStreptococcus agalactiae \u3c/em\u3eStrains with Chromosomal Deletions Evade Detection with Molecular Methods

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    Surveillance of circulating microbial populations is critical for monitoring the performance of a molecular diagnostic test. In this study, we characterized 31 isolates of Streptococcus agalactiae (group B Streptococcus [GBS]) from several geographic locations in the United States and Ireland that contain deletions in or adjacent to the region of the chromosome that encodes the hemolysin gene cfb, the region targeted by the Xpert GBS and GBS LB assays. PCR-negative, culture-positive isolates were recognized during verification studies of the Xpert GBS assay in 12 laboratories between 2012 and 2018. Whole-genome sequencing of 15 GBS isolates from 11 laboratories revealed four unique deletions of chromosomal DNA ranging from 181 bp to 49 kb. Prospective surveillance studies demonstrated that the prevalence of GBS isolates containing deletions in the convenience sample wa

    A Blueprint to Address Research Gaps in the Development of Biomarkers for Pediatric Tuberculosis

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    Childhood tuberculosis contributes significantly to the global tuberculosis disease burden but remains challenging to diagnose due to inadequate methods of pathogen detection in paucibacillary pediatric samples and lack of a child-specific host biomarker to identify disease. Accurately diagnosing tuberculosis in children is required to improve case detection, surveillance, healthcare delivery, and effective advocacy. In May 2014, the National Institutes of Health convened a workshop including researchers in the field to delineate priorities to address this research gap. This blueprint describes the consensus from the workshop, identifies critical research steps to advance this field, and aims to catalyze efforts toward harmonization and collaboration in this are

    Toward Earlier Inclusion of Pregnant and Postpartum Women in Tuberculosis Drug Trials: Consensus Statements From an International Expert Panel

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    Tuberculosis is a major cause of morbidity and mortality in women of childbearing age (15–44 years). Despite increased tuberculosis risk during pregnancy, optimal clinical treatment remains unclear: safety, tolerability, and pharmacokinetic data for many tuberculosis drugs are lacking, and trials of promising new tuberculosis drugs exclude pregnant women. To advance inclusion of pregnant and postpartum women in tuberculosis drug trials, the US National Institutes of Health convened an international expert panel. Discussions generated consensus statements (>75% agreement among panelists) identifying high-priority research areas during pregnancy, including: (1) preventing progression of latent tuberculosis infection, especially in women coinfected with human immunodeficiency virus; (2) evaluating new agents/regimens for treatment of multidrug-resistant tuberculosis; and (3) evaluating safety, tolerability and pharmacokinetics of tuberculosis drugs already in use during pregnancy and postpartum. Incorporating pregnant women into clinical trials would extend evidence-based tuberculosis prevention and treatment standards to this special population

    Direct Detection of \u3cem\u3eMycobacterium tuberculosis \u3c/em\u3ein Clinical Specimens Using Nucleic Acid Amplification Tests

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    Tuberculosis continues to be a significant cause of morbidity and mortality worldwide. Rapid detection of Mycobacterium tuberculosis directly in clinical specimens using nucleic acid amplification tests enables infected patients to be placed on appropriate therapy much sooner than when results of conventional culture methods are used. The availability of rapid results also facilitates infection control measures to interrupt transmission of tuberculosis in healthcare settings. The era of commercially available molecular diagnostics for detection of M. tuberculosis began 25 years ago and now encompasses multiple assays that can detect organisms in the M. tuberculosis complex. Several assays also detect chromosomal mutations associated with antimicrobial resistance to further refine therapeutic strategies early in the course of disease. NAATs have revolutionized the diagnosis of TB across the globe and have become the standard of care in many high-burden developing countries

    Shedding and Reversion of Oral Polio Vaccine Type 3 in Mexican Vaccinees: Comparison of Mutant Analysis by PCR and Enzyme Cleavage to a Real-Time PCR Assayâ–¿

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    A uracil-to-cytosine mutation at nucleotide position 472 of oral poliovirus vaccine type 3 (OPV3) contributes to the development of vaccine-associated paralytic poliomyelitis (VAPP). To analyze OPV3 shedding patterns, we previously used the multistep method of mutant analysis by PCR and enzyme cleavage (MAPREC). This involves conventional reverse transcription-PCR to detect OPV3, followed by a restriction digest to quantify position 472 reversion. Real-time PCR detects and quantifies nucleic acid as PCR occurs and avoids postreaction processing. The goal of this study was to compare a real-time PCR method to MAPREC. Seventy-three stool samples from Mexican OPV recipients underwent the reverse transcription-PCR step of MAPREC and real-time PCR. Real-time PCR identified 23% more OPV3-positive samples than conventional reverse transcription-PCR. When reversion was compared, the revertant proportion (RP), defined as the percentage of revertants in a sample, differed by ≤10% in 21/25 (84%) samples. The four samples differing by >10% were obtained within 5 days of OPV administration. The real-time PCR assay identified samples with an RP of ≥85% with 94% sensitivity and 86% specificity compared to MAPREC. The mean difference in RP between the two methods was 3.6% (95% confidence interval, −0.3 to 7.5%). Real-time PCR methods reliably detect OPV3, and reversion estimates correlate more consistently with MAPREC when OPV3 reversion rates are high. Detecting VAPP-related mutations by real-time PCR is rapid and efficient and can be useful in monitoring ongoing global polio eradication efforts

    The Rhetoric of the ‘Passive Patient’ in Indian Medical Negligence Cases

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    In this paper, I examine the rhetoric employed by court judgements, with a particular emphasis on the narrative construct of the ‘passive patient’. This construction advances and reinforces paternalistic values, which have scant regard for the patients’ preferences, values, or choices within the legal context. Further, I critique the rhetoric employed and argue that the use of this rhetoric is the basis for a precedent that limits the understanding and respect of patients. Through this paper, I present the contemporary use of the ‘passive patient’ construct in the context of the Indian legal system and describe how such constructions have become a source of normative justification for legal reasoning that jeopardizes the patient’s agency. I argue for the primacy of ‘respect for persons’ within Indian law and the need to treat each patient as a person who has agency, preferences, and values during clinical interactions. I conclude by suggesting that laws that adopt narratives that acknowledging the significance of patient engagement and the relevance of effective communication during clinical encounters would help cultivate a culture of patient-centred care, by moving beyond the rhetoric of ‘passive patient’ and the ‘health/choice’ dichotomy

    Clinical Case Definitions for Classification of Intrathoracic Tuberculosis in Children: An Update

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    Consensus case definitions for childhood tuberculosis have been proposed by an international expert panel, aiming to standardize the reporting of cases in research focusing on the diagnosis of intrathoracic tuberculosis in children. These definitions are intended for tuberculosis diagnostic evaluation studies of symptomatic children with clinical suspicion of intrathoracic tuberculosis, and were not intended to predefine inclusion criteria into such studies. Feedback from researchers suggested that further clarification was required and that these case definitions could be further improved. Particular concerns were the perceived complexity and overlap of some case definitions, as well as the potential exclusion of children with acute onset of symptoms or less severe disease. The updated case definitions proposed here incorporate a number of key changes that aim to reduce complexity and improve research performance, while maintaining the original focus on symptomatic children suspected of having intrathoracic tuberculosis. The changes proposed should enhance harmonized classification for intrathoracic tuberculosis disease in children across studies, resulting in greater comparability and the much-needed ability to pool study results
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