23 research outputs found

    Efficacy assessment of ultraviolet germicidal irradiation (UVGI) devices for inactivating airborne Mycobacterium tuberculosis

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    INTRODUCTION : Airborne transmission of Mycobacterium tuberculosis (TB) and other infectious agents within indoor environments has been a recognised hazard for decades. The increasing incidence of airborne diseases and drug resistance has renewed interest in ultraviolet germicidal irradiation (UVGI) to reduce transmission. The aim of this study was to determine the efficacy of UVGI devices, available in South Africa, for inactivating airborne TB bacteria. METHODOLOGY : Thirteen UVGI devices from major South African suppliers were challenged with M. tuberculosis H37Ra bacilli (~1 x 106 vegetative cells/ml) when OFF and when ON, for one hour. Air samples (n = 130) were collected using PTFE filters. Sample extracts were analysed using quantitative real time polymerase chain reaction (qPCR), targeting the 16 subunit ribosomal ribonucleic acid (16S rRNA) gene. The DNA extraction efficiency was also determined, using the Quanti-iT PicoGreen assay. Irradiance measurements, including ultraviolet-C (UVC) output and maintained UVC flux of the devices, were recorded using an integrating sphere. The data were analysed using descriptive and inferential statistics. RESULTS : There was no difference between the mean concentration of the DNA extracted from the aqueous and air samples (p = 0.3494). An accumulation of TB DNA copies/m3 with increasing time, when the devices were OFF, was observed as expected. Forty-six percent (6 of 13) of UVGI devices tested yielded 100% effectiveness in a controlled laboratory setting; 5 of 6 had built-in fans which may have contributed to their efficacy. The effectiveness of the remaining devices ranged from 43.7% to 95.1%. CONCLUSION : The efficacy of UVGI devices available in South Africa is highly variable, with minimum UVC output. The reduced levels of effectiveness of some devices might be due to the design of the devices, which needs to be reassessed by manufacturers. The effectiveness of UVGI devices and quantification of microbial survival rate can be assessed robustly using qPCR.The NHLS trust fund and the Presidents Emergency Plan for Aids Relief (PEPFAR) grant, together with the US-CDC grant (1U2GPS002710): CoAA to the CSIR to assist the South African National Department of Health and Provincial Departments of Health integrate TB/HIV Counselling and Testing, and Care and Treatment in the Republic of South Africa.http://www.occhealth.co.zaam2018Electrical, Electronic and Computer Engineerin

    Optimising a couples-focused intervention to increase couples’ HIV testing and counselling using the person-based approach: a qualitative study in Kwa-Zulu Natal, South Africa

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    Objectives This qualitative study explored how to optimise a couples-focused intervention to promote couples HIV testing and counselling (CHTC). Setting Community setting in Kwa-Zulu Natal, South Africa. Participants Qualitative interviews were conducted with 20 couples who had participated in a couples-focused intervention and five staff members delivering the intervention. Partners were interviewed individually by researchers of the same gender. Intervention A couples-focused intervention comprised of two group sessions and four couples counselling sessions was previously shown to significantly increase uptake to CHTC in Kwa-Zulu Natal, South Africa. However, more than half of couples participating in the intervention still chose not to test together during follow-up. Analysis The transcripts were analysed using the table of changes from the person-based approach. Proposed optimisations were discussed with a community group to ensure the intervention was as persuasive and acceptable as possible. Results Many couples found it challenging to discuss CHTC with their partner due to an implied lack of trust. Optimisations to the intervention were identified to increase readiness to discuss CHTC, including education about serodiscordance, discussions about CHTC by peer mentors and open discussion of personal barriers to CHTC during couples’ counselling sessions. Additional training for staff in open questioning techniques could help them feel more comfortable to explore couples’ perceived barriers to CHTC, rather than advising couples to test. A logic model was developed to show anticipated mechanisms through which the optimised intervention would increase uptake to CHTC, including increasing knowledge, increasing positive outcome beliefs and managing negative emotions. Conclusions In-depth qualitative research informed optimisations to a couples-focused intervention for further evaluation in South Africa to encourage uptake to CHTC. Suggestions are made for optimal methods to gain open feedback on intervention experiences where participants may be reluctant to share negative views

    First candidates for γ vibrational bands built on the [505] 11/2− neutron orbital in odd-A Dy isotopes:

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    Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd(α,2n)157Dy and 148Nd(12C,5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-A155,157Dy isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the core nuclei 154Dy and 156Dy are also discussed

    South African Paediatric Surgical Outcomes Study : a 14-day prospective, observational cohort study of paediatric surgical patients

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    BACKGROUND : Children comprise a large proportion of the population in sub-Saharan Africa. The burden of paediatric surgical disease exceeds available resources in Africa, potentially increasing morbidity and mortality. There are few prospective paediatric perioperative outcomes studies, especially in low- and middle-income countries (LMICs). METHODS : We conducted a 14-day multicentre, prospective, observational cohort study of paediatric patients (aged <16 yrs) undergoing surgery in 43 government-funded hospitals in South Africa. The primary outcome was the incidence of in-hospital postoperative complications. RESULTS : We recruited 2024 patients at 43 hospitals. The overall incidence of postoperative complications was 9.7% [95% confidence interval (CI): 8.4–11.0]. The most common postoperative complications were infective (7.3%; 95% CI: 6.2–8.4%). In-hospital mortality rate was 1.1% (95% CI: 0.6–1.5), of which nine of the deaths (41%) were in ASA physical status 1 and 2 patients. The preoperative risk factors independently associated with postoperative complications were ASA physcial status, urgency of surgery, severity of surgery, and an infective indication for surgery. CONCLUSIONS : The risk factors, frequency, and type of complications after paediatric surgery differ between LMICs and high-income countries. The in-hospital mortality is 10 times greater than in high-income countries. These findings should be used to develop strategies to improve paediatric surgical outcomes in LMICs, and support the need for larger prospective, observational paediatric surgical outcomes research in LMICs. CLINICAL TRIAL REGISTRATION : NCT03367832.Jan Pretorius Research Fund; Discipline of Anaesthesiology and Critical Care, Nelson R Mandela School of Medicine, University of KwaZulu-Natal; Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital and University of Cape Town; Department of Anaesthesia, University of the Witwatersrand; and the Paediatric Anaesthesia Community of South Africa (PACSA).https://bjanaesthesia.org2020-02-01gl2019Anaesthesiolog

    Determination of the Levels of Heavy Metals and Formaldehyde in Baby Clothes in South Africa: A Case Study of Stores in the Greater Cape Town Region

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    Herein, we report on the determination of formaldehyde, pH, and heavy metals (Pb, As, Co, Cr, Ni, and Cd) in various baby apparel (cotton, polyester, nylon, elastane, and polyethylene) of different colours (light, medium, and dark) purchased from both high-end and low-end market stores. The concentrations of the heavy metals were determined by inductively coupled plasma (ICP) after wet digestion and also after extraction using artificial sweat for a selected range of skin-contact baby apparel. The relative standard deviation for the determination of all heavy metals was less than 5% except for nickel which was 10.49%. The concentrations of the heavy metals in wet digested samples were found to be in the following range: Pb (0.02–23.662 mg/kg), As (0.009–0.033 mg/kg), Co (0.001–1.053 mg/kg), Cr (0.053–6.373 mg/kg), Ni (0.039–36.715 mg/kg), and Cd (0.001–0.914 mg/kg), whereas the concentrations in artificial sweat extracted samples were in the following range: Pb (0.006–1.658 mg/kg), As (not detected), Co (0.001–1.05 mg/kg), Cr (0.112–0.371 mg/kg), Ni (0.062–0.121 mg/kg), and Cd (0.001–0.018 mg/kg). The highest concentrations of Pb, Cr, and Co after wet digestion were found in baby apparel purchased from low-end market stores, whereas for As, Ni, and Cd were from high-end market stores. All the samples had a formaldehyde concentration within the acceptable limits recommended by Oeko-Tex. Out of the thirty-four samples analysed, fifteen samples were found to have a pH higher than Oeko-Tex limits. The pH values for the samples that exceeded the Oeko-Tex limits were in the alkali region, and the highest was 11.31 which exceeded by 3.81

    A phase II study of the sterilising activities of ofloxacin, gatifloxacin and moxifloxacin in pulmonary tuberculosis

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    SETTING: Current treatment for pulmonary tuberculosis (TB) might be shortened by the incorporation of fluoroquinolones (FQs). OBJECTIVES: A Phase II study aimed to assess the sterilising activities of three novel regimens containing FQs before a Phase III trial of a 4-month regimen containing gatifloxacin (GFX). DESIGN: A total of 217 newly diagnosed smear-positive patients were randomly allocated to one of four regimens: isoniazid (INH), pyrazinamide and rifampicin (RMP) with either ethambutol, GFX, moxifloxacin (MFX) or ofloxacin (OFX) for 2 months. At the end of the study, RMP and INH were given for 4 months. The rates of elimination of Mycobacterium tuberculosis were compared in the regimens using non-linear mixed effects modelling of the serial sputum colony counts (SSCC) during the first 8 weeks. RESULTS: After adjustment for covariates, MFX substitution appeared superior during the early phase of a biexponential fall in colony counts, but significant and similar acceleration of bacillary elimination during the late phase occurred with both GFX and MFX (P = 0.002). Substitution of OFX had no effect. These findings were supported by estimates of time to conversion, using Cox regression, but there were no significant differences in proportions culture-negative at 8 weeks. CONCLUSIONS: GFX and MFX improve the sterilising activity of regimens and might shorten treatment; their progression into Phase III trials therefore seems warranted. © 2008 The Union.Articl
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