35 results on '"Boyles TH"'
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2. Timing of antiretroviral therapy for HIV-1-associated tuberculosis.
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Boyles TH and Boyles, Tom H
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- 2012
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3. Diagnostic Prediction Model for Tuberculous Meningitis: An Individual Participant Data Meta-Analysis.
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Stadelman-Behar AM, Tiffin N, Ellis J, Creswell FV, Ssebambulidde K, Nuwagira E, Richards L, Lutje V, Hristea A, Jipa RE, Vidal JE, Azevedo RGS, Monteiro de Almeida S, Kussen GB, Nogueira K, Gualberto FAS, Metcalf T, Heemskerk AD, Dendane T, Khalid A, Ali Zeggwagh A, Bateman K, Siebert U, Rochau U, van Laarhoven A, van Crevel R, Ganiem AR, Dian S, Jarvis J, Donovan J, Nguyen Thuy Thuong T, Thwaites GE, Bahr NC, Meya DB, Boulware DR, and Boyles TH
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- Humans, Logistic Models, Tuberculosis, Meningeal diagnosis, Tuberculosis, Meningeal cerebrospinal fluid, Tuberculosis, Meningeal microbiology
- Abstract
No accurate and rapid diagnostic test exists for tuberculous meningitis (TBM), leading to delayed diagnosis. We leveraged data from multiple studies to improve the predictive performance of diagnostic models across different populations, settings, and subgroups to develop a new predictive tool for TBM diagnosis. We conducted a systematic review to analyze eligible datasets with individual-level participant data (IPD). We imputed missing data and explored three approaches: stepwise logistic regression, classification and regression tree (CART), and random forest regression. We evaluated performance using calibration plots and C-statistics via internal-external cross-validation. We included 3,761 individual participants from 14 studies and nine countries. A total of 1,240 (33%) participants had "definite" (30%) or "probable" (3%) TBM by case definition. Important predictive variables included cerebrospinal fluid (CSF) glucose, blood glucose, CSF white cell count, CSF differential, cryptococcal antigen, HIV status, and fever presence. Internal validation showed that performance varied considerably between IPD datasets with C-statistic values between 0.60 and 0.89. In external validation, CART performed the worst (C = 0.82), and logistic regression and random forest had the same accuracy (C = 0.91). We developed a mobile app for TBM clinical prediction that accounted for heterogeneity and improved diagnostic performance (https://tbmcalc.github.io/tbmcalc). Further external validation is needed.
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- 2024
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4. Association Between Minimum Inhibitory Concentration, Beta-lactamase Genes and Mortality for Patients Treated With Piperacillin/Tazobactam or Meropenem From the MERINO Study.
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Henderson A, Paterson DL, Chatfield MD, Tambyah PA, Lye DC, De PP, Lin RTP, Chew KL, Yin M, Lee TH, Yilmaz M, Cakmak R, Alenazi TH, Arabi YM, Falcone M, Bassetti M, Righi E, Rogers BA, Kanj SS, Bhally H, Iredell J, Mendelson M, Boyles TH, Looke DFM, Runnegar NJ, Miyakis S, Walls G, Khamis MAI, Zikri A, Crowe A, Ingram PR, Daneman N, Griffin P, Athan E, Roberts L, Beatson SA, Peleg AY, Cottrell K, Bauer MJ, Tan E, Chaw K, Nimmo GR, Harris-Brown T, and Harris PNA
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- Anti-Bacterial Agents adverse effects, Anti-Bacterial Agents pharmacology, Humans, Microbial Sensitivity Tests, Mortality, Reproducibility of Results, Meropenem adverse effects, Meropenem pharmacology, Piperacillin, Tazobactam Drug Combination adverse effects, Piperacillin, Tazobactam Drug Combination pharmacology, beta-Lactamases genetics
- Abstract
Introduction: This study aims to assess the association of piperacillin/tazobactam and meropenem minimum inhibitory concentration (MIC) and beta-lactam resistance genes with mortality in the MERINO trial., Methods: Blood culture isolates from enrolled patients were tested by broth microdilution and whole genome sequencing at a central laboratory. Multivariate logistic regression was performed to account for confounders. Absolute risk increase for 30-day mortality between treatment groups was calculated for the primary analysis (PA) and the microbiologic assessable (MA) populations., Results: In total, 320 isolates from 379 enrolled patients were available with susceptibility to piperacillin/tazobactam 94% and meropenem 100%. The piperacillin/tazobactam nonsusceptible breakpoint (MIC >16 mg/L) best predicted 30-day mortality after accounting for confounders (odds ratio 14.9, 95% confidence interval [CI] 2.8-87.2). The absolute risk increase for 30-day mortality for patients treated with piperacillin/tazobactam compared with meropenem was 9% (95% CI 3%-15%) and 8% (95% CI 2%-15%) for the original PA population and the post hoc MA populations, which reduced to 5% (95% CI -1% to 10%) after excluding strains with piperacillin/tazobactam MIC values >16 mg/L. Isolates coharboring extended spectrum β-lactamase (ESBL) and OXA-1 genes were associated with elevated piperacillin/tazobactam MICs and the highest risk increase in 30-day mortality of 14% (95% CI 2%-28%)., Conclusions: After excluding nonsusceptible strains, the 30-day mortality difference from the MERINO trial was less pronounced for piperacillin/tazobactam. Poor reliability in susceptibility testing performance for piperacillin/tazobactam and the high prevalence of OXA coharboring ESBLs suggests that meropenem remains the preferred choice for definitive treatment of ceftriaxone nonsusceptible Escherichia coli and Klebsiella., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)
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- 2021
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5. CheXaid: deep learning assistance for physician diagnosis of tuberculosis using chest x-rays in patients with HIV.
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Rajpurkar P, O'Connell C, Schechter A, Asnani N, Li J, Kiani A, Ball RL, Mendelson M, Maartens G, van Hoving DJ, Griesel R, Ng AY, Boyles TH, and Lungren MP
- Abstract
Tuberculosis (TB) is the leading cause of preventable death in HIV-positive patients, and yet often remains undiagnosed and untreated. Chest x-ray is often used to assist in diagnosis, yet this presents additional challenges due to atypical radiographic presentation and radiologist shortages in regions where co-infection is most common. We developed a deep learning algorithm to diagnose TB using clinical information and chest x-ray images from 677 HIV-positive patients with suspected TB from two hospitals in South Africa. We then sought to determine whether the algorithm could assist clinicians in the diagnosis of TB in HIV-positive patients as a web-based diagnostic assistant. Use of the algorithm resulted in a modest but statistically significant improvement in clinician accuracy ( p = 0.002), increasing the mean clinician accuracy from 0.60 (95% CI 0.57, 0.63) without assistance to 0.65 (95% CI 0.60, 0.70) with assistance. However, the accuracy of assisted clinicians was significantly lower ( p < 0.001) than that of the stand-alone algorithm, which had an accuracy of 0.79 (95% CI 0.77, 0.82) on the same unseen test cases. These results suggest that deep learning assistance may improve clinician accuracy in TB diagnosis using chest x-rays, which would be valuable in settings with a high burden of HIV/TB co-infection. Moreover, the high accuracy of the stand-alone algorithm suggests a potential value particularly in settings with a scarcity of radiological expertise., Competing Interests: Competing InterestsThe authors declare no competing interests., (© The Author(s) 2020.)
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- 2020
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6. Preparing healthcare facilities to operate safely and effectively during the COVID-19 pandemic: The missing piece in the puzzle.
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Wilkinson LS, Moosa S, Cooke R, Muller AM, and Boyles TH
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- Ambulatory Care Facilities, Betacoronavirus, COVID-19, Capacity Building, Coronavirus Infections prevention & control, Coronavirus Infections transmission, Disinfection, Environment Design, Hand Disinfection, Hospitals, Humans, Infection Control, Mobile Health Units, Pandemics prevention & control, Personal Protective Equipment supply & distribution, Pneumonia, Viral prevention & control, Pneumonia, Viral transmission, SARS-CoV-2, South Africa epidemiology, Ventilators, Mechanical supply & distribution, Coronavirus Infections epidemiology, Delivery of Health Care organization & administration, Health Facilities, Health Personnel, Pneumonia, Viral epidemiology
- Abstract
The stated objective of the COVID-19 lockdown was to allow time to prepare healthcare facilities. Preparation must include administrative and environmental measures, which when combined with personal protective equipment, minimise the risk of the spread of infection to patients and healthcare workers (HCWs) in facilities, allowing HCWs to safely provide essential services during the pandemic and limit the indirect effects of COVID-19 caused by healthcare disruption. We present our model for facility preparation based on colour-coded zones, social distancing, hand hygiene, rapid triage and separate management of symptomatic patients, and attention to infection transmission prevention between HCWs in communal staff areas. This model specifically addresses the challenges in preparing a facility for COVID-19 in a low-resource setting and in rural areas. In addition, we include links to resources to allow workers in low-resource settings to prepare their facilities adequately.
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- 2020
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7. Decision-making in the diagnosis of tuberculous meningitis.
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Boyles TH, Lynen L, and Seddon JA
- Abstract
Tuberculous meningitis (TBM) is the most devastating form of tuberculosis (TB) but diagnosis is difficult and delays in initiating therapy increase mortality. All currently available tests are imperfect; culture of Mycobacterium tuberculosis from the cerebrospinal fluid (CSF) is considered the most accurate test but is often negative, even when disease is present, and takes too long to be useful for immediate decision making. Rapid tests that are frequently used are conventional Ziehl-Neelsen staining and nucleic acid amplification tests such as Xpert MTB/RIF and Xpert MTB/RIF Ultra. While positive results will often confirm the diagnosis, negative tests frequently provide insufficient evidence to withhold therapy. The conventional diagnostic approach is to determine the probability of TBM using experience and intuition, based on prevalence of TB, history, examination, analysis of basic blood and CSF parameters, imaging, and rapid test results. Treatment decisions may therefore be both variable and inaccurate, depend on the experience of the clinician, and requests for tests may be inappropriate. In this article we discuss the use of Bayes' theorem and the threshold model of decision making as ways to improve testing and treatment decisions in TBM. Bayes' theorem describes the process of converting the pre-test probability of disease to the post-test probability based on test results and the threshold model guides clinicians to make rational test and treatment decisions. We discuss the advantages and limitations of using these methods and suggest that new diagnostic strategies should ultimately be tested in randomised trials., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Boyles TH et al.)
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- 2020
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8. A Clinical Prediction Score Including Trial of Antibiotics and C-Reactive Protein to Improve the Diagnosis of Tuberculosis in Ambulatory People With HIV.
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Boyles TH, Nduna M, Pitsi T, Scott L, Fox MP, and Maartens G
- Abstract
Background: The use of a "trial of antibiotics" as empiric therapy for bacterial pneumonia as a diagnostic tool for tuberculosis in people with HIV (PWH) was removed from World Health Organization (WHO) recommendations in 2007, based on expert opinion. Current guidelines recommend antibiotics only after 2 Xpert MTB/RIF tests (if available), chest x-ray, and clinical assessment have suggested that tuberculosis is unlikely. Despite this, a "trial of antibiotics" remains common in algorithms in low-resource settings, but its value is uncertain. C-reactive protein (CRP), which has been proposed as a "rule-out" test for tuberculosis, may be an objective marker of response to antibiotics., Methods: We performed a passive case-finding cohort study of adult PWH with a positive WHO symptom screen. All participants received antibiotics at first visit according to the local protocol and were reviewed to ascertain clinical response. Point-of-care CRP was measured at both visits. All patients had sputum tested with Xpert MTB/RIF Ultra (Ultra), and the reference standard was based on 2 sputum mycobacterial cultures. We explored multivariable prediction models (MPM) for tuberculosis based on 1 or 2 visits., Results: Seventy-five of 207 patients (36%) had confirmed tuberculosis. Clinical response to antibiotics after 2 days was a good predictor of disease. An MPM based on 2 visits, without CRP, had acceptable discrimination (c-statistic, 0.75) and calibration (goodness-of-fit P = .07). Addition of CRP after antibiotics improved the model moderately (c-statistic, 0.78). CRP at first visit was not an independent predictor of tuberculosis., Conclusions: In adult PWH seeking care for symptoms suggestive of tuberculosis, lack of response to antibiotics is a strong predictor of disease and is likely to be useful, particularly when access to Ultra is limited. CRP adds value when measured after antibiotics but is of limited value at first visit., (© The Author(s) 2020. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)
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- 2020
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9. Essential in vitro diagnostics for advanced HIV and serious fungal diseases: international experts' consensus recommendations.
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Bongomin F, Govender NP, Chakrabarti A, Robert-Gangneux F, Boulware DR, Zafar A, Oladele RO, Richardson MD, Gangneux JP, Alastruey-Izquierdo A, Bazira J, Boyles TH, Sarcarlal J, Nacher M, Obayashi T, Worodria W, Pasqualotto AC, Meya DB, Cheng B, Sriruttan C, Muzoora C, Kambugu A, Rodriguez Tudela JL, Jordan A, Chiller TM, and Denning DW
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- Diagnostic Tests, Routine, Humans, International Cooperation, AIDS-Related Opportunistic Infections diagnosis, Acquired Immunodeficiency Syndrome diagnosis, Consensus Development Conferences as Topic, Diagnostic Techniques and Procedures, Mycoses diagnosis
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- 2019
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10. Incremental yield and cost of urine Determine TB-LAM and sputum induction in seriously ill adults with HIV.
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Boyles TH, Griesel R, Stewart A, Mendelson M, and Maartens G
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- Adult, Algorithms, Female, Humans, Lipopolysaccharides economics, Male, Middle Aged, Mycobacterium tuberculosis drug effects, Mycobacterium tuberculosis genetics, Mycobacterium tuberculosis isolation & purification, Mycobacterium tuberculosis physiology, Prospective Studies, Sputum microbiology, Tuberculosis economics, Tuberculosis etiology, Tuberculosis microbiology, Diagnostic Techniques and Procedures economics, HIV Infections complications, Lipopolysaccharides urine, Sputum chemistry, Tuberculosis diagnosis
- Abstract
Background: Tuberculosis is a major cause of mortality among HIV-infected inpatients, and the World Health Organization (WHO) recommends an algorithm to improve diagnosis. The urine lateral flow lipoarabinomannan (LAM) and sputum Xpert MTB/RIF tests are promising tools, but the optimal diagnostic algorithm is unclear., Methods: This prospective cohort study enrolled HIV-positive inpatients with cough and WHO danger signs. The Xpert MTB/RIF test and mycobacterial culture were performed on sputum using sputum induction when necessary, and the LAM test was performed on stored urine. Tuberculosis was diagnosed by culture from any site. The diagnostic accuracy and costs of testing were determined for single and combined tests., Results: Tuberculosis was confirmed in 169 of 332 patients (50.9%). The yield of LAM, Xpert MTB/RIF on spontaneous sputum (Xpert Spot), and Xpert MTB/RIF on spontaneous or induced sputum (Xpert SI) was 35.5%, 23.1%, and 90.5%, respectively. When LAM was placed before Xpert Spot and Xpert SI in an algorithm, the yield was 50.9% and 92.3%, respectively. Adding culture to Xpert MTB/RIF only increased the yield by 1.2% and 2.7%, respectively. Use of the LAM test reduced costs., Conclusions: Sputum induction is important to increase the yield of Xpert MTB/RIF for seriously ill patients with HIV and cough. LAM testing has little effect on yield when sputum induction is available, but reduces costs and may have other benefits., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2018
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11. Effect of Piperacillin-Tazobactam vs Meropenem on 30-Day Mortality for Patients With E coli or Klebsiella pneumoniae Bloodstream Infection and Ceftriaxone Resistance: A Randomized Clinical Trial.
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Harris PNA, Tambyah PA, Lye DC, Mo Y, Lee TH, Yilmaz M, Alenazi TH, Arabi Y, Falcone M, Bassetti M, Righi E, Rogers BA, Kanj S, Bhally H, Iredell J, Mendelson M, Boyles TH, Looke D, Miyakis S, Walls G, Al Khamis M, Zikri A, Crowe A, Ingram P, Daneman N, Griffin P, Athan E, Lorenc P, Baker P, Roberts L, Beatson SA, Peleg AY, Harris-Brown T, and Paterson DL
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- Adult, Aged, Anti-Bacterial Agents adverse effects, Anti-Bacterial Agents pharmacology, Bacteremia drug therapy, Cause of Death, Ceftriaxone pharmacology, Drug Resistance, Bacterial, Escherichia coli drug effects, Escherichia coli Infections mortality, Female, Humans, Klebsiella Infections mortality, Male, Meropenem, Middle Aged, Penicillanic Acid adverse effects, Penicillanic Acid therapeutic use, Piperacillin adverse effects, Piperacillin therapeutic use, Piperacillin, Tazobactam Drug Combination, Thienamycins adverse effects, Anti-Bacterial Agents therapeutic use, Bacteremia mortality, Escherichia coli Infections drug therapy, Klebsiella Infections drug therapy, Klebsiella pneumoniae drug effects, Penicillanic Acid analogs & derivatives, Thienamycins therapeutic use
- Abstract
Importance: Extended-spectrum β-lactamases mediate resistance to third-generation cephalosporins (eg, ceftriaxone) in Escherichia coli and Klebsiella pneumoniae. Significant infections caused by these strains are usually treated with carbapenems, potentially selecting for carbapenem resistance. Piperacillin-tazobactam may be an effective "carbapenem-sparing" option to treat extended-spectrum β-lactamase producers., Objectives: To determine whether definitive therapy with piperacillin-tazobactam is noninferior to meropenem (a carbapenem) in patients with bloodstream infection caused by ceftriaxone-nonsusceptible E coli or K pneumoniae., Design, Setting, and Participants: Noninferiority, parallel group, randomized clinical trial included hospitalized patients enrolled from 26 sites in 9 countries from February 2014 to July 2017. Adult patients were eligible if they had at least 1 positive blood culture with E coli or Klebsiella spp testing nonsusceptible to ceftriaxone but susceptible to piperacillin-tazobactam. Of 1646 patients screened, 391 were included in the study., Interventions: Patients were randomly assigned 1:1 to intravenous piperacillin-tazobactam, 4.5 g, every 6 hours (n = 188 participants) or meropenem, 1 g, every 8 hours (n = 191 participants) for a minimum of 4 days, up to a maximum of 14 days, with the total duration determined by the treating clinician., Main Outcomes and Measures: The primary outcome was all-cause mortality at 30 days after randomization. A noninferiority margin of 5% was used., Results: Among 379 patients (mean age, 66.5 years; 47.8% women) who were randomized appropriately, received at least 1 dose of study drug, and were included in the primary analysis population, 378 (99.7%) completed the trial and were assessed for the primary outcome. A total of 23 of 187 patients (12.3%) randomized to piperacillin-tazobactam met the primary outcome of mortality at 30 days compared with 7 of 191 (3.7%) randomized to meropenem (risk difference, 8.6% [1-sided 97.5% CI, -∞ to 14.5%]; P = .90 for noninferiority). Effects were consistent in an analysis of the per-protocol population. Nonfatal serious adverse events occurred in 5 of 188 patients (2.7%) in the piperacillin-tazobactam group and 3 of 191 (1.6%) in the meropenem group., Conclusions and Relevance: Among patients with E coli or K pneumoniae bloodstream infection and ceftriaxone resistance, definitive treatment with piperacillin-tazobactam compared with meropenem did not result in a noninferior 30-day mortality. These findings do not support use of piperacillin-tazobactam in this setting., Trial Registration: anzctr.org.au Identifiers: ACTRN12613000532707 and ACTRN12615000403538 and ClinicalTrials.gov Identifier: NCT02176122.
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- 2018
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12. Antibiotic use and resistance: Knowledge, attitudes and perceptions among primary care prescribers in South Africa.
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Farley E, Stewart A, Davies MA, Govind M, Van den Bergh D, and Boyles TH
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- Adult, Cross-Sectional Studies, Drug Resistance, Bacterial, Health Care Surveys, Humans, Logistic Models, Middle Aged, Private Sector, Public Sector, South Africa, Anti-Bacterial Agents therapeutic use, Health Knowledge, Attitudes, Practice, Health Personnel statistics & numerical data, Practice Patterns, Physicians' statistics & numerical data, Primary Health Care statistics & numerical data
- Abstract
Background: Antibiotic resistance (ABR) is a major threat to global health, driven in part by inappropriate prescription of antibiotics in primary care., Objectives: To describe South African (SA) prescribers' knowledge of, attitudes to and perceptions of ABR., Methods: We conducted a cross-sectional survey of knowledge of, attitudes to and perceptions of ABR among a convenience sample of primary healthcare providers in SA, the majority from the private sector. We used logistic regression to examine associations between knowledge and prescribing behaviours., Results: Of 264 prescriber respondents, 95.8% (230/240) believed that ABR is a significant problem in SA and 66.5% (157/236) felt pressure from patients to prescribe antibiotics. The median knowledge score was 5/7, and scores were highest in respondents aged <55 years (p=0.0001). Prescribers with higher knowledge scores were more likely than those with lower scores to believe that to decrease ABR, narrow-spectrum antibiotics should be used (adjusted odds ratio (aOR) 1.29, 95% confidence interval (CI) 1 - 1.65) and more likely to report that explaining disease features that should prompt follow-up was a useful alternative to prescribing (aOR 1.47, 95% CI 1.058 - 2.04), and were less likely to report that antibiotics cannot harm the patient if they are not needed, so they prescribe when not necessary (aOR 0.57, 95% CI 0.38 - 0.84)., Conclusions: Prescribers of antibiotics in the private sector in SA were aware of the problem of ABR, but felt pressure from patients to prescribe. Those with higher knowledge scores reported positive prescribing behaviours, suggesting that more education is needed to tackle the problem of ABR.
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- 2018
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13. Erratum to South African guideline for the management of community-acquired pneumonia in adults.
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Boyles TH, Brink A, Calligaro GL, Cohen C, Dheda K, Maartens G, Richards GA, van Zyl Smit R, Smith C, Wasserman S, Whitelaw AC, and Feldman C
- Abstract
[This corrects the article DOI: 10.21037/jtd.2017.05.31.].
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- 2018
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14. South African guideline for the management of community-acquired pneumonia in adults.
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Boyles TH, Brink A, Calligaro GL, Cohen C, Dheda K, Maartens G, Richards GA, van Zyl Smit R, Smith C, Wasserman S, Whitelaw AC, and Feldman C
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Competing Interests: Conflicts of Interest: AC Whitelaw has received honoraria to the Institute from MSD, Novartis, AstraZeneca, and Takeda. A Brink has received honoraria from MSD, Cipla and Pfizer. C Feldman has acted on the advisory board and/or speakers bureau of companies manufacturing and/or marketing macrolide antibiotics (Abbott, Aspen GSK, Pfizer, Sandoz) and ceftaroline (AstraZeneca/Pfizer) and companies manufacturing and/or marketing the pneumococcal conjugate vaccine (Pfizer). C Cohen has received received grant funds to the Institute from Sanofi and travel paid for by Sanofi and Parexel. GA Richards has received honoraria from Aspen, Cipla, MSD, Pfizer, AstraZeneca, Sanofi, BMS and Fresenius Kabi. K Dheda has received grants, free products/kits from Hain Life Sciences, Alere Diagnostics, FIND Diagnostics, Pfizer, Novartis, Cipla, GSK, AstraZeneca and Sanofi-Aventis. The other authors have no conflicts of interest to declare.
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- 2017
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15. South African medical students' perceptions and knowledge about antibiotic resistance and appropriate prescribing: Are we providing adequate training to future prescribers?
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Wasserman S, Potgieter S, Shoul E, Constant D, Stewart A, Mendelson M, and Boyles TH
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Background: Education of medical students has been identified by the World Health Organization as an important aspect of antibiotic resistance (ABR) containment. Surveys from high-income countries consistently reveal that medical students recognise the importance of antibiotic prescribing knowledge, but feel inadequately prepared and require more education on how to make antibiotic choices. The attitudes and knowledge of South African (SA) medical students regarding ABR and antibiotic prescribing have never been evaluated., Objective: To evaluate SA medical students' perceptions, attitudes and knowledge about antibiotic use and resistance, and the perceived quality of education relating to antibiotics and infection., Methods: This was a cross-sectional survey of final-year students at three medical schools, using a 26-item self-administered questionnaire. The questionnaires recorded basic demographic information, perceptions about antibiotic use and ABR, sources, quality, and usefulness of current education about antibiotic use, and questions to evaluate knowledge. Hard-copy surveys were administered during whole-class lectures., Results: A total of 289 of 567 (51%) students completed the survey. Ninety-two percent agreed that antibiotics are overused and 87% agreed that resistance is a significant problem in SA - higher proportions than those who thought that antibiotic overuse (63%) and resistance (61%) are problems in the hospitals where they had worked (p<0.001). Most reported that they would appreciate more education on appropriate use of antibiotics (95%). Only 33% felt confident to prescribe antibiotics, with similar proportions across institutions. Overall, prescribing confidence was associated with the use of antibiotic prescribing guidelines (p=0.003), familiarity with antibiotic stewardship (p=0.012), and more frequent contact with infectious diseases specialists (p<0.001). There was an overall mean correct score of 50% on the knowledge questionnaire, with significant differences between institutions. Students who used antibiotic prescribing guidelines and found their education more useful scored higher on knowledge questionnaires., Conclusion: There are low levels of confidence with regard to antibiotic prescribing among final-year medical students in SA, and most students would like more education in this area. Perceptions that ABR is less of a problem in their local setting may contribute to inappropriate prescribing behaviours. Differences exist between medical schools in knowledge about antibiotic use, with suboptimal scores across institutions. The introduction and use of antibiotic prescribing guidelines and greater contact with specialists in antibiotic prescribing may improve prescribing behaviours.
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- 2017
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16. Why do clinical trials of Xpert® MTB/RIF fail to show an effect on patient relevant outcomes?
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Boyles TH
- Subjects
- Antibiotics, Antitubercular pharmacology, Antibiotics, Antitubercular therapeutic use, Humans, Mycobacterium tuberculosis drug effects, Mycobacterium tuberculosis genetics, Real-Time Polymerase Chain Reaction, Rifampin pharmacology, Rifampin therapeutic use, Tuberculosis, Multidrug-Resistant drug therapy, Tuberculosis, Multidrug-Resistant microbiology, Tuberculosis, Pulmonary drug therapy, Tuberculosis, Pulmonary microbiology, Clinical Trials as Topic, Mycobacterium tuberculosis isolation & purification, Treatment Outcome, Tuberculosis, Multidrug-Resistant diagnosis, Tuberculosis, Pulmonary diagnosis
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- 2017
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17. Brief Report: Flow Rate of Cerebrospinal Fluid Through a Spinal Needle Can Accurately Predict Intracranial Pressure in Cryptococcal Meningitis.
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Boyles TH, Gatley E, Wasserman S, and Meintjes G
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- Adult, Female, Humans, Male, AIDS-Related Opportunistic Infections pathology, Cerebrospinal Fluid chemistry, Chemical Phenomena, Intracranial Hypertension diagnosis, Meningitis, Cryptococcal pathology, Spinal Puncture methods
- Abstract
Background: Patients with HIV-associated cryptococcal meningitis (CM) commonly present with raised intracranial pressure (ICP). Aggressive management of raised ICP reduces mortality but requires manometers, which are unavailable in most resource-limited settings. The law of Poiseuille states that the rate of flow of liquid through a tube is directly proportional to the difference in pressure between each end, and it may be possible to indirectly determine ICP by measuring flow of CSF through a spinal needle rather than using a manometer., Methods: A convenience sample of CM patients requiring lumbar puncture (LP) (with 22-G spinal needle) for ICP measurement and control were enrolled. ICP was first measured using a narrow bore manometer. After removing the manometer, the number of drops of CSF flowing from the spinal needle in 15 seconds was counted., Results: Thirty-two patients had 89 LPs performed (range, 1-23). Fifty-four had high opening pressure with a CSF flow rate of 16-200 drops/min, and 35 had normal pressure with a CSF flow rate of 8-140 drops/min. Area under the fitted receiver operator character curve was 0.89. A flow rate cutoff to define high pressure of ≥40 drops/min correctly classified 75 of 89 LPs (accuracy 84%)., Conclusions: It is technically feasible to indirectly estimate CSF pressure to an accuracy that is clinically useful by counting drops of CSF flowing from a spinal needle. The optimal cutoff value for defining high pressure using a standard 22-G spinal needle is ≥40 drops/min. These findings have the potential to improve CM management in resource-limited settings.
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- 2017
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18. Sustained reduction in antibiotic consumption in a South African public sector hospital; Four year outcomes from the Groote Schuur Hospital antibiotic stewardship program.
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Boyles TH, Naicker V, Rawoot N, Raubenheimer PJ, Eick B, and Mendelson M
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- Anti-Bacterial Agents economics, Bacterial Infections drug therapy, Bacteriological Techniques statistics & numerical data, Clinical Laboratory Techniques statistics & numerical data, Drug Costs statistics & numerical data, Hospitals, Public, Hospitals, Teaching, Humans, Mortality, Patient Readmission statistics & numerical data, South Africa, Anti-Bacterial Agents therapeutic use, Bacterial Infections diagnosis, Bacteriological Techniques economics, Clinical Laboratory Techniques economics, Education, Medical, Continuing methods, Practice Patterns, Physicians' statistics & numerical data
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Background: Overuse of antibiotics has driven global bacterial resistance to the extent that we have entered a post-antibiotic era, where infections that were once easily treatable are now becoming untreatable. Efforts to control consumption have focused on antibiotic stewardship programmes (ASPs), aimed at optimising use., Objective: To report antibiotic consumption and cost over 4 years from a public hospital ASP in South Africa (SA)., Methods: A comprehensive ASP comprising online education, a dedicated antibiotic prescription chart and weekly dedicated ward rounds was introduced at Groote Schuur Hospital, Cape Town, in 2012. Electronic records were used to collect data on volume and cost of antibiotics and related laboratory tests, and to determine inpatient mortality and 30-day readmission rates. These data were compared with a control period before the intervention., Results: Total antibiotic consumption fell from 1 046 defined daily doses/1 000 patient days in 2011 (control period) to 868 by 2013 and remained at similar levels for the next 2 years. This was driven by reductions in intravenous antibiotic use, particularly ceftriaxone. Inflation-adjusted cost savings on antibiotics were ZAR3.2 million over 4 years. Laboratory tests increased over the same period with a total increased cost of ZAR0.4 million. There was no significant change in mortality or 30-day readmission rates., Conclusions: The effects of a comprehensive ASP on medical inpatients at a public sector hospital in SA were durable over 4 years, leading to a reduction in total antibiotic consumption without adverse effect. When increased laboratory costs were offset there was a net cost saving of ZAR2.8 million.
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- 2017
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19. A priori estimation of diagnostic thresholds could improve the reporting of diagnostic studies of tuberculosis.
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Boyles TH and Kengne AP
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- Humans, Models, Statistical, Predictive Value of Tests, Probability, Prognosis, Reproducibility of Results, Time Factors, Tuberculosis epidemiology, Tuberculosis therapy, Decision Support Techniques, Tuberculosis diagnosis
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- 2016
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20. Ebola: Personal view from the field--Sierra Leone.
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Boyles TH
- Subjects
- Epidemics, Health Personnel organization & administration, Hemorrhagic Fever, Ebola epidemiology, Humans, Sierra Leone, Delivery of Health Care organization & administration, Hemorrhagic Fever, Ebola therapy, Patient Isolation
- Abstract
Experiences of healthcare workers responding to the Ebola epidemic in West Africa vary with the types of facility. Patients suspected of having Ebola virus disease (EVD) must be isolated from each other as well as from the wider community until testing is complete; in Sierra Leone such facilities were called Ebola holding units (EHUs). Once EVD was confirmed, patients were moved to Ebola treatment units (ETUs), where they could be cohorted together safely and treatment efforts focused on EVD itself. While a number of purpose-built units combined an EHU with an ETU, my personal experience was of working in a number of stand-alone EHUs in Freetown, Sierra Leone.
- Published
- 2015
- Full Text
- View/download PDF
21. Diagnostic accuracy of tuberculin skin test self-reading by HIV patients in a low-resource setting.
- Author
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Cox V, de Azevedo V, Stinson K, Wilkinson L, Rangaka M, and Boyles TH
- Subjects
- Adult, Female, Humans, Male, Predictive Value of Tests, South Africa, World Health Organization, Diagnostic Self Evaluation, HIV Infections complications, Tuberculin Test, Tuberculosis diagnosis
- Abstract
Background: The World Health Organization recommends tuberculin skin tests (TSTs) where feasible to identify individuals most likely to benefit from isoniazid preventive therapy (IPT). The requirement for TST reading after 48-72 h by a trained nurse is a barrier to implementation and increases loss to follow-up., Methods: Patients with human immunodeficiency virus (HIV) infection were recruited from a primary care clinic in South Africa and trained by a lay counsellor to interpret their own TST. The TST was placed by a nurse, and the patient was asked to return 2 days later with their self-reading result, followed by blinded reading by a trained nurse (reference)., Results: Of 227 patients, 210 returned for TST reading; 78% interpreted their test correctly: those interpreting it as negative were more likely to be correct (negative predictive value 93%) than those interpreting it as positive (positive predictive value 42%); 10/36 (28%) positive TST results were read as negative by the patient., Conclusions: Patients with HIV in low-resource settings can be trained to interpret their own TST. Those interpreting it as positive should return to the clinic within 48-72 h for confirmatory reading and IPT initiation; those with a negative interpretation can return at their next scheduled visit and initiate IPT at that time if appropriate.
- Published
- 2015
- Full Text
- View/download PDF
22. Blood cultures taken from patients attending emergency departments in South Africa are an important antibiotic stewardship tool, which directly influences patient management.
- Author
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Boyles TH, Davis K, Crede T, Malan J, Mendelson M, and Lesosky M
- Subjects
- Adult, Anti-Bacterial Agents therapeutic use, Bacteremia drug therapy, Bacteremia microbiology, Cohort Studies, Community-Acquired Infections drug therapy, Diabetes Mellitus blood, Diabetes Mellitus microbiology, Fungemia drug therapy, Fungemia microbiology, HIV Seropositivity, Humans, Middle Aged, Prospective Studies, Sepsis drug therapy, Sepsis microbiology, South Africa epidemiology, Bacteremia epidemiology, Blood microbiology, Community-Acquired Infections epidemiology, Community-Acquired Infections microbiology, Emergency Service, Hospital, Fungemia epidemiology
- Abstract
Background: Febrile illness with suspected blood stream infection (BSI) is a common reason for admission to hospital in Africa and blood cultures are therefore an important investigation. Data on the prevalence and causes of community acquired BSI in Africa are scarce and there are no studies from South Africa. There are no validated clinical prediction rules for use of blood cultures in Africa., Methods: A prospective observational cohort study of patients attending 2 urban emergency departments in Cape Town, South Africa. The decision to take a blood culture was made by the attending clinician and information available at the time of blood draw was collected. Bottles were weighed to measure volume of blood inoculated., Results: 500 blood culture sets were obtained from 489 patients. 39 (7.8 %) were positive for pathogens and 13 (2.6 %) for contaminants. Significant independent predictors of positive cultures were diastolic blood pressure <60 mmHg, pulse >120 bpm, diabetes and a suspected biliary source of infection, but not HIV infection. Positive results influenced patient management in 36 of 38 (95 %) cases with the organism being resistant to the chosen empiric antibiotic in 9 of 38 (24 %). Taking <8 ml of blood was predictive of a negative culture. The best clinical prediction rule had a negative predictive value (NPV) of 92 % which is unlikely to be high enough to be clinically useful., Discussion: Blood cultures taken from patients attending emergency departments in a high HIV prevalent city in South Africa are frequently positive and almost always influence patient management. At least 8 ml of blood should be inoculated into each bottle., Conclusion: Blood cultures should be taken from all patients attending EDs in South Africa suspected of having BSI particularly if diabetic, with hypotension, tachycardia or if biliary sepsis is suspected.
- Published
- 2015
- Full Text
- View/download PDF
23. The Individualised versus the Public Health Approach to Treating Ebola.
- Author
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Boyles TH
- Subjects
- Africa, Western, Disease Outbreaks, Georgia, Hospitals, University, Humans, Public Health, Health Resources, Hemorrhagic Fever, Ebola therapy
- Abstract
Tom Boyles reflects on differing approaches taken for treating patients with Ebola virus disease in low- and high-resource settings.
- Published
- 2015
- Full Text
- View/download PDF
24. False-positive Xpert(®) MTB/RIF assays and previous treatment.
- Author
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Boyles TH, Hughes J, Cox V, Burton R, Meintjes G, and Mendelson M
- Subjects
- Female, Humans, Antibiotics, Antitubercular therapeutic use, Drug Resistance, Bacterial, Mycobacterium tuberculosis drug effects, Mycobacterium tuberculosis isolation & purification, Nucleic Acid Amplification Techniques methods, Respiratory Tract Infections diagnosis, Rifampin therapeutic use, Tuberculosis diagnosis, Tuberculosis, Pulmonary drug therapy
- Published
- 2015
- Full Text
- View/download PDF
25. Appropriate use of the Xpert® MTB/RIF assay in suspected tuberculous meningitis.
- Author
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Boyles TH and Thwaites GE
- Subjects
- Antibiotics, Antitubercular therapeutic use, Cerebrospinal Fluid microbiology, Humans, Mycobacterium tuberculosis isolation & purification, Predictive Value of Tests, Sensitivity and Specificity, Specimen Handling, Tuberculosis, Meningeal drug therapy, Molecular Diagnostic Techniques methods, Nucleic Acid Amplification Techniques methods, Tuberculosis, Meningeal diagnosis
- Abstract
We disagree with the recommendation by the World Health Organization to use Xpert(®) MTB/RIF on cerebrospinal fluid for the initial diagnosis of tuberculous meningitis (TBM). TBM is a devastating disease requiring empirical treatment even when the probability of disease is low. We suggest that a useful TBM diagnostic test needs a negative predictive value (NPV) of ⩾ 99% so that empirical treatment can be stopped safely. The NPV of Xpert is around 84%, making a negative test of limited value. While better tests are awaited, a composite score, possibly combining Xpert with clinical variables and with high NPV, should be constructed and validated prospectively.
- Published
- 2015
- Full Text
- View/download PDF
26. False-positive Xpert® MTB/RIF assays in previously treated patients: need for caution in interpreting results.
- Author
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Boyles TH, Hughes J, Cox V, Burton R, Meintjes G, and Mendelson M
- Subjects
- False Positive Reactions, Female, Humans, Lung microbiology, Respiratory Tract Infections microbiology, Sensitivity and Specificity, Sputum microbiology, Tuberculosis microbiology, Mycobacterium tuberculosis isolation & purification, Nucleic Acid Amplification Techniques methods, Respiratory Tract Infections diagnosis, Tuberculosis diagnosis
- Abstract
Xpert(®) MTB/RIF is the initial diagnostic test of choice for tuberculosis (TB). It is not known if false-positive results are more common in previously treated patients. We report four patients with successful treatment for TB up to 5 years previously who presented with respiratory tract infection and were Xpert-positive, but had negative TB cultures and clinical improvement without anti-tuberculosis treatment. We hypothesise that the Xpert results were false-positive due to the presence of dead Mycobacterium tuberculosis bacilli in lungs and sputum. Further work is required to determine the specificity of Xpert in previously treated patients.
- Published
- 2014
- Full Text
- View/download PDF
27. Antibiotic stewardship ward rounds and a dedicated prescription chart reduce antibiotic consumption and pharmacy costs without affecting inpatient mortality or re-admission rates.
- Author
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Boyles TH, Whitelaw A, Bamford C, Moodley M, Bonorchis K, Morris V, Rawoot N, Naicker V, Lusakiewicz I, Black J, Stead D, Lesosky M, Raubenheimer P, Dlamini S, and Mendelson M
- Subjects
- Hospitals statistics & numerical data, Humans, Inpatients statistics & numerical data, Anti-Bacterial Agents, Drug Utilization statistics & numerical data
- Abstract
Background: Antibiotic consumption is a major driver of bacterial resistance. To address the increasing burden of multi-drug resistant bacterial infections, antibiotic stewardship programmes are promoted worldwide to rationalize antibiotic prescribing and conserve remaining antibiotics. Few studies have been reported from developing countries and none from Africa that report on an intervention based approach with outcomes that include morbidity and mortality., Methods: An antibiotic prescription chart and weekly antibiotic stewardship ward round was introduced into two medical wards of an academic teaching hospital in South Africa between January-December 2012. Electronic pharmacy records were used to collect the volume and cost of antibiotics used, the patient database was analysed to determine inpatient mortality and 30-day re-admission rates, and laboratory records to determine use of infection-related tests. Outcomes were compared to a control period, January-December 2011., Results: During the intervention period, 475.8 defined daily doses were prescribed per 1000 inpatient days compared to 592.0 defined daily doses/1000 inpatient days during the control period. This represents a 19.6% decrease in volume with a cost reduction of 35% of the pharmacy's antibiotic budget. There was a concomitant increase in laboratory tests driven by requests for procalcitonin. There was no difference in inpatient mortality or 30-day readmission rate during the control and intervention periods., Conclusions: Introduction of antibiotic stewardship ward rounds and a dedicated prescription chart in a developing country setting can achieve reduction in antibiotic consumption without harm to patients. Increased laboratory costs should be anticipated when introducing an antibiotic stewardship program.
- Published
- 2013
- Full Text
- View/download PDF
28. Noakes' low-carbohydrate, high-fat diet: call for evidence.
- Author
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Boyles TH and Wasserman S
- Subjects
- Female, Humans, Cardiovascular Diseases prevention & control, Diet, Fat-Restricted adverse effects, Feeding Behavior, Women's Health
- Published
- 2013
- Full Text
- View/download PDF
29. Test performance of beta-glucan for Pneumocystis jirovecii pneumonia put in a clinical context.
- Author
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Boyles TH
- Subjects
- Diagnosis, Differential, HIV Infections complications, Humans, Pneumonia, Pneumocystis complications, Sensitivity and Specificity, Pneumocystis carinii isolation & purification, Pneumonia, Pneumocystis diagnosis, beta-Glucans
- Published
- 2013
- Full Text
- View/download PDF
30. The pros and cons of urinary lipoarabinomannan testing.
- Author
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Boyles TH
- Subjects
- Female, Humans, Male, HIV Seropositivity microbiology, HIV Seropositivity urine, Lipopolysaccharides urine, Mycobacterium tuberculosis metabolism, Sputum microbiology, Tuberculosis urine
- Published
- 2012
- Full Text
- View/download PDF
31. Should tuberculin skin testing be a prerequisite to prolonged IPT for HIV-infected adults?
- Author
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Boyles TH and Maartens G
- Subjects
- Adult, Antitubercular Agents adverse effects, Humans, Isoniazid adverse effects, Mass Screening, Practice Guidelines as Topic, Risk, Sensitivity and Specificity, Tuberculosis diagnosis, Antitubercular Agents administration & dosage, HIV Infections complications, Infection Control methods, Isoniazid administration & dosage, Tuberculin Test, Tuberculosis prevention & control
- Published
- 2012
- Full Text
- View/download PDF
32. Failure to eradicate Isospora belli diarrhoea despite immune reconstitution in adults with HIV--a case series.
- Author
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Boyles TH, Black J, Meintjes G, and Mendelson M
- Subjects
- Adult, Diarrhea complications, Diarrhea parasitology, Fatal Outcome, Female, HIV Infections parasitology, Humans, Isospora, Isosporiasis complications, Isosporiasis parasitology, Male, Diarrhea immunology, Diarrhea prevention & control, Disease Eradication, HIV Infections complications, HIV Infections immunology, Isosporiasis immunology, Isosporiasis prevention & control
- Abstract
Isospora belli causes diarrhoea in patients with AIDS. Most respond to targeted therapy and recommendations are that secondary prophylaxis can be stopped following immune reconstitution with ART. We report eight cases of chronic isosporiasis that persisted despite standard antimicrobial therapy, secondary prophylaxis, and good immunological and virological response to ART. Median CD4 nadir was 175.5 cells/mm(3) and median highest CD4 while symptomatic was 373 cells/mm(3). Overall 34% of stool samples and 63% of duodenal biopsy specimens were positive for oocytes. Four patients died, two remain symptomatic and two recovered. Possible explanations for persistence of symptoms include host factors such as antigen specific immune deficiency or generalised reduction in gut immunity. Parasite factors may include accumulating resistance to co-trimoxazole. Research is required to determine the optimum dose and duration of co-trimoxazole therapy and whether dual therapy may be necessary. Mortality was high and pending more data we recommend extended treatment with high-dose co-trimoxazole in similar cases.
- Published
- 2012
- Full Text
- View/download PDF
33. The prevalence of hepatitis B infection in a rural South African HIV clinic.
- Author
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Boyles TH and Cohen K
- Subjects
- Adult, Alanine Transaminase blood, CD4 Lymphocyte Count, Female, Hepatitis B diagnosis, Humans, Male, Prevalence, South Africa epidemiology, HIV Infections complications, Hepatitis B epidemiology
- Abstract
The prevalence of hepatitis B virus (HBV) infection in 1 765 HIV-positive patients in rural Eastern Cape was 7.1%. This is lower than the previously reported rural prevalence and is similar to urban prevalence. Male sex and baseline alanine aminotransferease (ALT) were significant predictors of HBV status. Most HBV-positive patients had normal baseline ALT, making ALT an insensitive screening test for HBV status.
- Published
- 2011
34. Factors influencing retention in care after starting antiretroviral therapy in a rural South African programme.
- Author
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Boyles TH, Wilkinson LS, Leisegang R, and Maartens G
- Subjects
- Adult, CD4-Positive T-Lymphocytes cytology, Cohort Studies, Female, HIV Infections mortality, Humans, Male, Medication Adherence, Middle Aged, Poverty, Pregnancy, Pregnancy Complications, Infectious drug therapy, Rural Health Services organization & administration, Rural Population, South Africa, Treatment Outcome, Anti-Retroviral Agents therapeutic use, Communicable Disease Control methods, HIV Infections drug therapy, Patient Compliance
- Abstract
Introduction: The prognosis of patients with HIV in Africa has improved with the widespread use of antiretroviral therapy (ART) but these successes are threatened by low rates of long-term retention in care. There are limited data on predictors of retention in care, particularly from rural sites., Methods: Prospective cohort analysis of outcome measures in adults from a rural HIV care programme in Madwaleni, Eastern Cape, South Africa. The ART programme operates from Madwaleni hospital and seven primary care feeder clinics with full integration between inpatient and outpatient services. Outreach workers conducted home visits for defaulters., Results: 1803 adults initiated ART from June 2005 to May 2009. At the end of the study period 82.4% were in active care or had transferred elsewhere, 11.1% had died and 6.5% were lost to follow-up (LTFU). Independent predictors associated with an increased risk of LTFU were CD4 nadir >200, initiating ART as an inpatient or while pregnant, and younger age, while being in care for >6 months before initiating ART was associated with a reduced risk. Independent factors associated with an increased risk of mortality were baseline CD4 count <50 and initiating ART as an inpatient, while being in care for >6 months before initiating ART and initiating ART while pregnant were associated with a reduced risk., Conclusions: Serving a socioeconomically deprived rural population is not a barrier to successful ART delivery. Patients initiating ART while pregnant and inpatients may require additional counselling and support to reduce LTFU. Providing HIV care for patients not yet eligible for ART may be protective against being LTFU and dying after ART initiation.
- Published
- 2011
- Full Text
- View/download PDF
35. A validated method for quantifying macrovesicular hepatic steatosis in chronic hepatitis C.
- Author
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Boyles TH, Johnson S, Garrahan N, Freedman AR, and Williams GT
- Subjects
- Cytoplasmic Vesicles pathology, Humans, Image Processing, Computer-Assisted, Observer Variation, Reproducibility of Results, Fatty Liver pathology, Hepatitis C, Chronic pathology
- Abstract
Hepatic steatosis is increasingly seen as an important prognostic factor in chronic hepatitis C infection (HCV). The commonly used semiquantitative method of measuring steatosis is based on a study that excluded patients with HCV. Several potentially useful methods of quantifying steatosis using computer-assisted morphometric analysis have been proposed, but none has been validated against a proposed gold standard other than the method they were intended to replace. We present a novel method and propose a gold standard based on manual measurements. The manual method is time consuming but shows little interobserver error, and the mean value of 3 observations by separate investigators is proposed as the gold standard. The computer-assisted method is fast, with a single interactive step that shows minimal interobserver variation. It accurately identifies biopsies with <1% steatosis (7 of 7) and predicts the gold standard value for biopsies with > 1% steatosis with narrow CIs (geometric mean ratio 0.85 with 95% CIs 0.77-0.95). This novel method of computer-assisted morphometric analysis is fast, reliable, and suitable for future research in HCV steatosis. It may be used to reanalyze previous studies. The semiquantitative method of assessing steatosis remains appropriate for clinical purposes.
- Published
- 2007
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