Publications by authors named "Ronald Dallas"

Background: Pediatric immunocompromised patients are at an increased risk of severe respiratory syncytial virus (RSV) infection. Here, we aimed to describe the clinical course and outcomes of RSV infection in immunocompromised children.

Methods: This single-center study at St.

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Pneumocystis jirovecii pneumonia (PJP) in hematopoietic cell transplant (HCT) recipients can be prevented by efficient prophylaxis. We surveyed HCT centers in North America to assess their PJP prophylaxis practices. Most institutions used intravenous (IV) pentamidine (29.

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Background: Respiratory viral infections are common among pediatric transplant patients, with human rhinovirus (HRV) being the most frequent. In pediatric patients undergoing hemopoietic cell transplant (HCT), infection with HRV has been associated with progression to lower respiratory tract infection (LRTI) and adverse outcomes. We describe the clinical presentation and outcomes of HRV infection in children undergoing HCT.

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Objective: To evaluate the performance of existing sepsis scores for prediction of adverse outcomes in children with cancer admitted to the ICU with suspected sepsis.

Design: Retrospective chart review using data available at 1, 6, 12, and 24 h after ICU admission to calculate the Pediatric Risk of Mortality 3 (PRISM-3), Pediatric Sequential Organ Failure Assessment (pSOFA), Paediatric Logistic Organ Dysfunction 2 (PELOD-2), and Quick Pediatric Sequential Organ Failure Assessment (qSOFA) scores. Area under the receiver operator characteristic curve (AUROC) was used to evaluate performance for prediction of attributable mortality.

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Background: The role of SARS-CoV-2 viral load in predicting contagiousness, disease severity, transmissibility, and clinical decision-making continues to be an area of great interest. However, most studies have been in adults and have evaluated SARS-CoV-2 loads using cycle thresholds (Ct) values, which are not standardized preventing consistent interpretation critical to understanding clinical impact and utility. Here, a quantitative SARS-CoV-2 reverse-transcription digital PCR (RT-dPCR) assay normalized to WHO International Units was applied to children at risk of severe disease diagnosed with COVID-19 at St.

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Importance: Live vaccines (measles-mumps-rubella [MMR] and varicella-zoster virus [VZV]) have not been recommended after solid organ transplant due to concern for inciting vaccine strain infection in an immunocompromised host. However, the rates of measles, mumps, and varicella are rising nationally and internationally, leaving susceptible immunocompromised children at risk for life-threating conditions.

Objective: To determine the safety and immunogenicity of live vaccines in pediatric liver and kidney transplant recipients.

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From 8 December 2021 to 26 January 2023, tixagevimab-cilgavimab (T-C) was authorized for pre-exposure prophylaxis of COVID-19. During this period, we used a multidisciplinary team to communicate, screen, approach, and administer T-C to eligible patients. Twenty-seven patients were eligible.

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Background: Despite preventive measures, infections continue to pose significant risks to pediatric allogeneic hematopoietic cell transplantation (allo-HCT) recipients. The gut microbiota has been linked to clinical outcomes following adult allo-HCT. This study evaluated whether similar disruptions or differing microbiota patterns were associated with infection risk in pediatric allo-HCT.

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Immunocompromised patients can have life-threatening adenoviral infection. Viral load in blood and stool is commonly used to guide antiviral therapy. We developed and evaluated a digital polymerase chain reaction assay to quantify human adenovirus in the respiratory tract and showed that higher peak load correlates with disseminated infection, mechanical ventilation, and death.

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Introduction: Youth living with HIV in the US have low rates of viral suppression, in part because of challenges with antiretroviral therapy adherence.

Methods: Daily dosing in the Adolescent Medicine Trials Network for HIV/AIDS Interventions 152 study, a randomized controlled trial of a 12-week adherence intervention (triggered escalating real-time adherence intervention) for viremic youth, compared with standard of care (SOC), was measured by electronic dose monitoring (EDM) throughout 48 weeks of follow-up. EDM data collected over the first 24 weeks were used to characterize patterns of antiretroviral therapy adherence with group-based trajectory models.

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Youth living with HIV (YLWH) in the US have low rates of viral suppression (VS). In a prospective randomized clinical trial (ATN152) that enrolled 89 YLWH on antiretroviral therapy (ART) with detectable viral load, we evaluated a 12 week triggered escalating real-time adherence (TERA) intervention with remote coaching, electronic dose monitoring (EDM), and outreach for missed/delayed doses compared to standard of care (SOC). Median [Q1, Q3] percent days with EDM opening was higher in TERA (72% (47%, 89%)) versus SOC (41% (21%, 59%); p < 0.

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Article Synopsis
  • * Conducted on healthy volunteers, the study found that SJ733 was well-tolerated with no serious side effects, and the boosted regimen significantly increased drug exposure compared to unboosted doses.
  • * The findings promote the continued development of SJ733 and introduce a new strategy to improve antimalarial treatment by enhancing drug pharmacokinetics through a boosting agent.
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Background: Although antibiotic prophylaxis with levofloxacin can reduce the risk of serious infection in immunocompromised patients, the potential contribution of prophylaxis to antibiotic resistance is a major drawback. We aimed to identify the effects of levofloxacin prophylaxis, given to paediatric patients with acute lymphoblastic leukaemia to prevent infections during induction chemotherapy, on antibiotic resistance in gastrointestinal microbiota after completion of induction and consolidation therapy.

Methods: This prospective, single-centre (St Jude Children's Research Hospital, Memphis, TN, USA) cohort study included children (≤18 years) receiving therapy for newly diagnosed acute lymphoblastic leukaemia and who received either primary levofloxacin prophylaxis or no antibacterial prophylaxis (aside from prophylaxis with trimethoprim-sulfamethoxazole) and provided at least two stool samples, including one after completion of induction therapy.

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A sizable portion of youth (ages 13-24) living with HIV in the United States have unsuppressed viral load. The AIDS Interventions (ATN) 152 study [evaluating the Triggered Escalating Real-Time Adherence (TERA) intervention] baseline data were examined to identify correlates of high viremia (>5000 copies/mL) and self-reported adherence, which can help in planning of differentiated services for viremic youth. Depression, HIV-stigma, and cannabis use were common in this sample of 87 youth.

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Background: Guidelines for the use of antiretroviral agents in adults and adolescents with HIV recommend that antiretroviral therapy (ART) be started as soon as possible. While rapid initiation of ART in adults with HIV has been well-described, there is relatively little information describing this approach for youth.

Methods: On April 1, 2018, St.

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Respiratory syncytial virus (RSV) is associated with adverse outcomes among immunocompromised patients. Inhaled ribavirin has been shown to improve mortality rates. The Small-Particle Aerosol Generator delivery system (SPAG-2) is the only FDA-cleared device to deliver inhaled ribavirin.

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Noroviruses are a leading cause of gastroenteritis worldwide. Although infections in healthy individuals are self-resolving, immunocompromised individuals are at risk for chronic disease and severe complications. Chronic norovirus infections in immunocompromised hosts are often characterized by long-term virus shedding, but it is unclear whether this shed virus remains infectious.

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We performed a retrospective study to determine the epidemiology of Rothia mucilaginosa infections among pediatric cancer patients. Over 20 years, 37 cases were identified; 27% developed complications, but there was no infection-related mortality. All cases were successfully treated with vancomycin.

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Background: (+)-SJ000557733 (SJ733) is a novel, orally bioavailable inhibitor of Plasmodium falciparum ATP4. In this first-in-human and induced blood-stage malaria phase 1a/b trial, we investigated the safety, tolerability, pharmacokinetics, and antimalarial activity of SJ733 in humans.

Methods: The phase 1a was a single-centre, dose-escalation, first-in-human study of SJ733 allowing modifications to dose increments and dose-cohort size on the basis of safety and pharmacokinetic results.

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Hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients are at increased risk for Clostridioides difficile infection (CDI). We conducted a multicenter retrospective study to describe the incidence of CDI in children transplanted between January 2010 and June 2013. Nested case-control substudies, matched 1:1 by transplant type, institution, patient age, and time of year (quartile) of transplant, identified CDI risk factors.

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Maximizing vaccine efficacy is critical, but previous research has failed to provide a one-size-fits-all solution. Although vitamin A and vitamin D supplementation studies have been designed to improve vaccine efficacy, experimental results have been inconclusive. Information is urgently needed to explain study discrepancies and to provide guidance for the future use of vitamin supplements at the time of vaccination.

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It is unknown if religiousness/spirituality influences end-of-life treatment preferences among adolescents. Investigators assessed whether religiousness/spirituality moderates the relationship between an advance care planning intervention and end-of-life treatment preferences among 85 primarily African-American adolescents living with HIV/AIDS in outpatient-hospital-based HIV-specialty clinics in the United States. Adolescents aged 14-21 years living with HIV/AIDS and their families were randomized to three-weekly-60-minute sessions either: advance care planning (survey, goals of care conversation, advance directive); or control (developmental history, safety tips, nutrition/exercise).

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Acute respiratory tract infections are a major cause of respiratory morbidity and mortality in pediatric patients worldwide. However, accurate viral and immunologic markers to predict clinical outcomes of this patient population are still lacking. Droplet digital PCR assays for influenza and respiratory syncytial virus (RSV) were designed and performed in 64 respiratory samples from 23 patients with influenza virus infection and 73 samples from 19 patients with RSV infection.

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Background: Metagenomic next-generation sequencing (NGS) of cerebrospinal fluid (CSF) has the potential to identify a broad range of pathogens in a single test.

Methods: In a 1-year, multicenter, prospective study, we investigated the usefulness of metagenomic NGS of CSF for the diagnosis of infectious meningitis and encephalitis in hospitalized patients. All positive tests for pathogens on metagenomic NGS were confirmed by orthogonal laboratory testing.

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Background: Youth living with HIV (YLWH) are confronted with many self-care challenges that can be experienced as overwhelming in the context of normal developmental processes that characterize adolescence and young adulthood. A sizable minority of YLWH have unsuppressed viral loads in the United States attributable to antiretroviral therapy (ART) nonadherence. Interventions to promote sustained viral suppression in YLWH are needed.

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