Clinical Evaluation of a Line-Probe Assay for Tuberculosis Detection and Drug-Resistance Prediction in Namibia.

Treatment of tuberculosis requires rapid information about Mycobacterium tuberculosis (Mtb) drug susceptibility to ensure effective therapy and optimal outcomes. At the tuberculosis referral hospital in Windhoek, Namibia, a country of high tuberculosis incidence, we evaluated the diagnostic accuracy of a line-probe-assay (LPA), GenID, for the molecular diagnosis of Mtb infection and drug resistance in patients with suspected tuberculosis (cohort 1) and confirmed rifampin (RIF)-resistant tuberculosis (cohort 2). GenID test results were compared to Xpert MTB/RIF and/or Mtb culture and antimicrobial suceptibilty testing. GenID LPA was applied to 79 and 55 samples from patients in cohort 1 and cohort 2, respectively. The overall sensitivity of GenID LPA for the detection of Mtb DNA in sputum from patients with detectable and undetectable acid-fast bacilli by sputum smear microscopy was 93.3% (56/60; 95% confidence interval = 83.8-98.2) and 22.7% (5/22; 7.8-45.4). The sensitivity/specificity for the detection of drug resistance was 84.2% (32/38; 68.7-94.0)/100% (19/19; 82.4-100.0) for RIF, 89.7% (26/29; 72.6-97.8)/91.7% (22/24; 73.0-99.0) for isoniazid, and 85.7% (6/7; 42.1-99.6)/94.7% (18/19; 74.0-99.9) for fluoroquinolones; 23.6% of tests for second-line injectable resistance were invalid despite repeat testing. The diagnosis of tuberculosis by detection of Mtb DNA in sputum by GenID LPA depends strongly on the detection of acid-fast bacilli in sputum specimen. Prediction of drug resistance by GenID did not reach the World Health Organization (WHO) target product profile. IMPORTANCE Mycobacterium tuberculosis (Mtb) drug-resistance detection is crucial for successful control of tuberculosis. Line-probe assays (LPA) are frequently used to detect resistance to rifampin, isoniazid, fluoroquinolones (FQs), and second-line injectables (SLIs). GenID RIF/isoniazid (INH), FQ, and SLI LPA have not been widely tested and used so far. This study tested the diagnostic performance of the GenID LPA in a high-incidence TB/HIV, real-world setting in Namibia. The LPA demonstrates only an acceptable diagnostic performance for Mtb and drug-resistance detection. The diagnostic sensitivity and specificity fall short of the WHO suggested target product profiles for LPA

Evidence for high sugar content of baby foods in South Africa

Background. Early-life exposure to excess sugar affects eating behaviour and creates a predisposition to non-communicable diseases (NCDs). While reducing sugar consumption has been high on the public health agenda, little is known about the sugar content of baby foods.Objectives. To describe and analyse the sugar content of baby foods in South Africa (SA).Methods. A cross-sectional study was conducted to analyse the sugar content of baby foods. The study sample included commercially available baby foods targeted at children aged <12 months, sold in supermarkets and by other major retailers in SA. Primary data were obtained from the packaging, and sugar content was compared with recommended intake guidelines. Bivariate analyses were conducted to determine whether there were any associations between the sugar content, added sugar and the characteristics of foods.Results. Over 70% of products were sweet in taste, with one in four containing added sugars. Sugar content was high in 78% of the foods sampled. Over 80% of cereals and pureed desserts contained added sugar. Fewer than 10% of pureed composite meal and pureed fruit and vege­table categories contained added sugar. Most products adhered to SA labelling standards, but none had front-of-pack nutritional information.Conclusions. The SA baby food market is characterised by products with a high sugar content, promoting an environment that encourages development of sweet-taste preferences and in the long term contributing to the rising burden of NCDs. There is an urgent need for mandatory regulation of sugar in baby foods.

The classification of chronic osteomyelitis

As a result of the heterogeneous nature of chronic osteomyelitis and the complexity of management strategy formulation, more than ten classification systems have been published over the past 40 years. Historical systems, used in the classification of chronic osteomyelitis, remain useful in terms of the description of the nature and origin of the disease. They fail, however, to provide the user with sufficient information in order to select the appropriate treatment strategy. As a result, more comprehensive classifications have subsequently been proposed. Accurate host stratification, in particular, is considered to be essential. The physiological status of the host serves as the primary indicator of the patient’s ability to effect healing of bone and soft tissues, as well as their ability to launch an effective immune response in conjunction with antibiotic therapy. Despite the development of more comprehensive classification systems, many shortcomings remain within the domain of disease classification and host stratification.http://www.scielo.org.za/scielo.php?script=sci_serial&pid=1681-150X&lng=pt&nrm=isoam201

The management of chronic osteomyelitis : Part I – Diagnostic work-up and surgical principles

To date, no evidence-based guidelines for the treatment of chronic osteomyelitis exist. Owing to certain similarities, treatment philosophies applicable to musculoskeletal tumour surgery may be applied in the management of chronic osteomyelitis. This novel approach not only reinforces certain important treatment principles, but may also allow for improved patient selection as surgical margins may be customised according to relevant host factors. When distilled to its most elementary level, management is based on a choice between either a palliative or curative approach. Unfortunately there are currently no objective criteria to guide selection of the most appropriate treatment pathway. The pre-operative diagnostic work-up should be tailored according to the relevant objective, albeit confirming the clinical suspicion of the presence of infection, host stratification, anatomical disease classification, pre-operative planning or post-operative follow-up. MRI and PET-CT are emerging as the imaging modalities of choice. Interleukin-6, in combination with CRP, has been shown to have excellent sensitivity in the diagnosis of implant-associated infection. Molecular methods are growing rapidly as the method of choice in pathogen detection. Chronic osteomyelitis, as is the case with musculoskeletal tumours, can only be eradicated through complete resection of all infected bone. Chemotherapy, in the form of antibiotics, only plays an adjuvant role. Dead space management is essential following debridement, and the appropriate strategy should be selected according to the anatomical nature of the disease. Provision of adequate bony stability is crucial as it promotes revascularisation and maximisation of the host’s immune response. Although there is currently a variety of fixation options available, external fixation is generally preferred.South African Orthopaedic Associationhttp://www.saoa.org.za/publications/saojam201

Tuberculous arthritis of native joints – a systematic review and European Bone and Joint Infection Society workgroup report

Introduction: The aim of this systematic review was to assess the existing published data on the diagnosis and management of tuberculosis (TB) arthritis involving native joints in adults aged 18 years and older. Methods: This study was performed in accordance with the guidelines provided in the Preferred Reporting Items for Systematic reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR). Results: The systematic review of the literature yielded 20 data sources involving 573 patients from nine countries. There was considerable variation amongst the studies in terms of the approach to diagnosis and management. The diagnosis was mostly made by microbiological tissue culture. Medical management involved a median of 12 months of anti-tubercular treatment (interquartile range, IQR, of 8–16; range of 4–18 months). The duration of preoperative treatment ranged from 2 to 12 weeks. Surgery was performed on 87 % of patients and varied from arthroscopic debridement to complete synovectomies combined with total joint arthroplasty. The mean follow-up time of all studies was 26 months (range of 3–112 months). Recurrence rates were reported in most studies, with an overall average recurrence rate of approximately 7.4 % (35 of 475 cases). Conclusions: The current literature on TB arthritis highlights the need for the establishment of standardized guidelines for the confirmation of the diagnosis. Further research is needed to define the optimal approach to medical and surgical treatment. The role of early debridement in active TB arthritis needs to be explored further. Specifically, comparative studies are required to address questions around the use of medical treatment alone vs. in combination with surgical intervention.</p

Recombination dynamics of a human Y-chromosomal palindrome:rapid GC-biased gene conversion, multi-kilobase conversion tracts, and rare inversions

The male-specific region of the human Y chromosome (MSY) includes eight large inverted repeats (palindromes) in which arm-to-arm similarity exceeds 99.9%, due to gene conversion activity. Here, we studied one of these palindromes, P6, in order to illuminate the dynamics of the gene conversion process. We genotyped ten paralogous sequence variants (PSVs) within the arms of P6 in 378 Y chromosomes whose evolutionary relationships within the SNP-defined Y phylogeny are known. This allowed the identification of 146 historical gene conversion events involving individual PSVs, occurring at a rate of 2.9-8.4×10(-4) events per generation. A consideration of the nature of nucleotide change and the ancestral state of each PSV showed that the conversion process was significantly biased towards the fixation of G or C nucleotides (GC-biased), and also towards the ancestral state. Determination of haplotypes by long-PCR allowed likely co-conversion of PSVs to be identified, and suggested that conversion tract lengths are large, with a mean of 2068 bp, and a maximum in excess of 9 kb. Despite the frequent formation of recombination intermediates implied by the rapid observed gene conversion activity, resolution via crossover is rare: only three inversions within P6 were detected in the sample. An analysis of chimpanzee and gorilla P6 orthologs showed that the ancestral state bias has existed in all three species, and comparison of human and chimpanzee sequences with the gorilla outgroup confirmed that GC bias of the conversion process has apparently been active in both the human and chimpanzee lineages

South African dyslipidaemia guideline consensus statement

The European Society of Cardiology together with the European Atherosclerosis Society published updated dyslipidaemia guidelines in 2011. SA Heart and the Lipid and Atherosclerosis Society of Southern Africa officially adopt these guidelines. This statement adapts aspects of the guidelines to the South African situation. Using the updated Framingham risk charts, interventional strategies are based according to the cardiovascular risk score and low-density lipoprotein cholesterol (LDL-C) levels. The Framingham risk score refers to the 10-year risk of any cardiovascular event, and includes four categories of risk. Treatment targets are those of the European guidelines. The LDL-C goal is 1.8mmol/l for the very high-risk group (&gt;30%), 2.5mmol/l for the high-risk group (15 - 30%), and 3mmol/l for those below 15% risk. Intensive management of dyslipidaemia in South Africa will significantly reduce the cardiovascular disease health burden

QuantiFERON®-TB gold in-tube performance for diagnosing active tuberculosis in children and adults in a high burden setting.

To determine whether QuantiFERON®-TB Gold In-Tube (QFT) can contribute to the diagnosis of active tuberculosis (TB) in children in a high-burden setting and to assess the performance of QFT and tuberculin skin test (TST) in a prospective cohort of TB suspect children compared to adults with confirmed TB in Tanzania. Sensitivity and specificity of QFT and TST for diagnosing active TB as well as indeterminate QFT rates and IFN-γ levels were assessed in 211 TB suspect children in a Tanzanian district hospital and contrasted in 90 adults with confirmed pulmonary TB. Sensitivity of QFT and TST in children with confirmed TB was 19% (5/27) and 6% (2/31) respectively. In adults sensitivity of QFT and TST was 84% (73/87) and 85% (63/74). The QFT indeterminate rate in children and adults was 27% and 3%. Median levels of IFN-γ were lower in children than adults, particularly children <2 years and HIV infected. An indeterminate result was associated with age <2 years but not malnutrition or HIV status. Overall childhood mortality was 19% and associated with an indeterminate QFT result at baseline. QFT and TST showed poor performance and a surprisingly low sensitivity in children. In contrast the performance in Tanzanian adults was good and comparable to performance in high-income countries. Indeterminate results in children were associated with young age and increased mortality. Neither test can be recommended for diagnosing active TB in children with immature or impaired immunity in a high-burden setting

South African Dyslipidaemia Guideline Consensus Statement: A joint statement from the South African Heart Association (SA Heart) and the Lipid and Atherosclerosis Society of Southern Africa (LASSA)

The European Society of Cardiology together with the European Atherosclerosis Society published updated dyslipidaemia guidelines in 2011. SA Heart and the Lipid and Atherosclerosis Society of Southern Africa officially adopt these guidelines. This statement adapts aspects of the guidelines to the South African situation. Using the updated Framingham risk charts, interventional strategies are based according to the cardiovascular risk score and low-density lipoprotein cholesterol (LDL-C) levels. The Framingham risk score refers to the 10-year risk of any cardiovascular event, and includes four categories of risk. Treatment targets are those of the European guidelines. The LDL-C goal is 1.8 mmol/l for the very high-risk group (&gt;30%), 2.5 mmol/l for the high-risk group (15 - 30%), and 3 mmol/l for those below 15% risk. Intensive management of dyslipidaemia in South Africa will significantly reduce the cardiovascular disease health burden