The ‘ins and outs’ of colonoscopy at Wits Donald Gordon Medical Centre, South Africa: A practice audit of the outpatient endoscopy unit

Background. In South Africa, there are no national guidelines for the conduct or quality assessment of colonoscopy, the gold standard for investigation and diagnosis of bowel pathology.Objectives. To describe the clinical profile of patients and evaluate the practice of colonoscopy using procedural quality indicators at the Wits Donald Gordon Medical Centre (WDGMC) outpatient endoscopy unit (OEU).Methods. We conducted a prospective, clinical practice audit of colonoscopies performed on adults (≥18 years of age). A total of 1 643 patients were included in the study and variables that were collected enabled the assessment of adequacy of bowel preparation, length of withdrawal time and calculation of caecal intubation rate (CIR), polyp detection rate (PDR) and adenoma detection rate (ADR). We stratified PDR and ADR by sex, age, population group, withdrawal time and bowel preparation. CIR, PDR and ADR estimates were compared between patient groups by the χ2 test; Fisher’s exact test was used for 2 × 2 tables. A p-value <0.05 was used. Benchmark recommendations by the American Society for Gastrointestinal Endoscopy (ASGE)/American College of Gastroenterology (ACG) Task Force on Colorectal Cancer (CRC) were used in this audit to assess individual endoscopist performance and that of the endoscopy unit as a whole.Results. The mean age of patients was 55.7 (standard deviation (SD) 14.4; range 18 - 91) years, ~60% were female, and the majority (75.5%) were white. Of the outpatients, 77.6% had adequate bowel preparation (ASGE/ACG benchmark ≥85%). The CIR was 97.0% overall, and screening colonoscopy was 96.3% (ASGE/ACG benchmark ≥90% overall and ≥95% for screening colonoscopies). The median withdrawal time for negative-result screening colonoscopies was 5.7 minutes (interquartile range (IQR) 4.2 - 9.3; range 1.1 - 20.6) (ASGE/ACG benchmark ≥ 6minutes), and PDR and ADR were 27.6% and 15.6%, respectively (ASGE/ACG benchmark ADR ≥25%). We demonstrated a 23.7% increase in PDR and 14.1% increase in ADR between scopes that had mean withdrawal times of ≥6 minutes and <6 minutes, respectively. Although the number of black Africans in the study was relatively small, our results showed that they have similar ADRs and PDRs to the white population group, contradicting popular belief.Conclusions. The WDGMC OEU performed reasonably well against the international guidelines, despite some inadequacy in bowel preparation and lower than recommended median withdrawal times on negative-result colonoscopy. Annual auditing of clinical practice and availability of these data in the public domain will become standard of care, making this audit a baseline for longitudinal observation, assessing the impact of interventions, and contributing to the development of local guidelines

Adult liver transplantation in Johannesburg South Africa 2004 2016: Balancing good outcomes constrained resources and limited donors

Background. Liver transplantation is the standard of care for the treatment of liver failure worldwide, yet millions of people living in sub-Saharan Africa remain without access to these services. South Africa (SA) has two liver transplant centres, one in Cape Town and the other in Johannesburg, where Wits Donald Gordon Medical Centre (WDGMC) started an adult liver transplant programme in 2004.Objectives. To describe the outcomes of the adult liver transplant programme at WDGMC.Methods. This was a retrospective review of all adult orthotopic liver transplants performed at WDGMC from 16 August 2004 to 30 June 2016 with a minimum follow-up of 6 months. The primary outcome was recipient and graft survival and the effect of covariates on survival. Kaplan-Meier survival analysis included all adults who underwent their first transplant for end-stage liver disease (ESLD) (N=275). Proportional hazards regression analysis using hazard ratios (HRs) was conducted to determine which covariates were associated with a significantly increased risk of mortality.Results. A total of 297 deceased-donor liver transplants were performed during the study period; 19/297 (6.4%) were for acute liver failure (ALF) and the remainder were for ESLD. The median age of recipients was 51 years (interquartile range 41 - 59), and two-thirds were male. The most common cause of ESLD was primary sclerosing cholangitis. The median follow-up was 3.2 years, and recipient survival was characterised in the following intervals: 90 days = 87.6% (95% confidence interval (CI) 83.1 - 91.0), 1 year = 81.7% (95% CI 76.6 - 85.8), and 5 years = 71.0% (95% CI 64.5 - 76.5). Allograft survival was similar: 90 days = 85.8% (95% CI 81.1 - 89.4), 1 year = 81.0% (95% CI 75.8 - 85.2), and 5 years = 69.1% (95% CI 62.6 - 74.7). The most significant covariates that impacted on mortality were postoperative biliary leaks (HR 2.0 (95% CI 1.05 - 3.80)), recipient age >60 years at time of transplant (HR 2.06 (95% CI 1.06 - 3.99)), theatre time >8  hours (HR 3.13 (95% CI 1.79 - 5.48)), and hepatic artery thrombosis (HR 5.58 (95% CI 3.09 - 10.08)). The most common infectious cause of death was invasive fungal infection.Conclusions. This study demonstrates that outcomes of the adult orthotopic liver transplant programme at WDGMC are comparable with international transplant centres. Management of biliary complications, early hepatic artery thrombosis and post-transplant infections needs to be improved. Access to liver transplantation services is still extremely limited, but can be improved by addressing the national shortage of deceased donors and establishing a national regulatory body for solid-organ transplantation in SA.Â

Adult liver transplantation in Johannesburg, South Africa (2004 - 2016): Balancing good outcomes, constrained resources and limited donors

Background. Liver transplantation is the standard of care for the treatment of liver failure worldwide, yet millions of people living in sub-Saharan Africa remain without access to these services. South Africa (SA) has two liver transplant centres, one in Cape Town and the other in Johannesburg, where Wits Donald Gordon Medical Centre (WDGMC) started an adult liver transplant programme in 2004.Objectives. To describe the outcomes of the adult liver transplant programme at WDGMC.Methods. This was a retrospective review of all adult orthotopic liver transplants performed at WDGMC from 16 August 2004 to 30 June 2016 with a minimum follow-up of 6 months. The primary outcome was recipient and graft survival and the effect of covariates on survival. Kaplan-Meier survival analysis included all adults who underwent their first transplant for end-stage liver disease (ESLD) (N=275). Proportional hazards regression analysis using hazard ratios (HRs) was conducted to determine which covariates were associated with a significantly increased risk of mortality.Results. A total of 297 deceased-donor liver transplants were performed during the study period; 19/297 (6.4%) were for acute liver failure (ALF) and the remainder were for ESLD. The median age of recipients was 51 years (interquartile range 41 - 59), and two-thirds were male. The most common cause of ESLD was primary sclerosing cholangitis. The median follow-up was 3.2 years, and recipient survival was characterised in the following intervals: 90 days = 87.6% (95% confidence interval (CI) 83.1 - 91.0), 1 year = 81.7% (95% CI 76.6 - 85.8), and 5 years = 71.0% (95% CI 64.5 - 76.5). Allograft survival was similar: 90 days = 85.8% (95% CI 81.1 - 89.4), 1 year = 81.0% (95% CI 75.8 - 85.2), and 5 years = 69.1% (95% CI 62.6 - 74.7). The most significant covariates that impacted on mortality were postoperative biliary leaks (HR 2.0 (95% CI 1.05 - 3.80)), recipient age >60 years at time of transplant (HR 2.06 (95% CI 1.06 - 3.99)), theatre time >8  hours (HR 3.13 (95% CI 1.79 - 5.48)), and hepatic artery thrombosis (HR 5.58 (95% CI 3.09 - 10.08)). The most common infectious cause of death was invasive fungal infection.Conclusions. This study demonstrates that outcomes of the adult orthotopic liver transplant programme at WDGMC are comparable with international transplant centres. Management of biliary complications, early hepatic artery thrombosis and post-transplant infections needs to be improved. Access to liver transplantation services is still extremely limited, but can be improved by addressing the national shortage of deceased donors and establishing a national regulatory body for solid-organ transplantation in SA.

Natural and Vaccine-Mediated Immunity to Salmonella Typhimurium is Impaired by the Helminth Nippostrongylus brasiliensis

The impact of exposure to multiple pathogens concurrently or consecutively on immune function is unclear. Here, immune responses induced by combinations of the bacterium Salmonella Typhimurium (STm) and the helminth Nippostrongylus brasiliensis (Nb), which causes a murine hookworm infection and an experimental porin protein vaccine against STm, were examined. Mice infected with both STm and Nb induced similar numbers of Th1 and Th2 lymphocytes compared with singly infected mice, as determined by flow cytometry, although lower levels of secreted Th2, but not Th1 cytokines were detected by ELISA after re-stimulation of splenocytes. Furthermore, the density of FoxP3+ T cells in the T zone of co-infected mice was lower compared to mice that only received Nb, but was greater than those that received STm. This reflected the intermediate levels of IL-10 detected from splenocytes. Co-infection compromised clearance of both pathogens, with worms still detectable in mice weeks after they were cleared in the control group. Despite altered control of bacterial and helminth colonization in co-infected mice, robust extrafollicular Th1 and Th2-reflecting immunoglobulin-switching profiles were detected, with IgG2a, IgG1 and IgE plasma cells all detected in parallel. Whilst extrafollicular antibody responses were maintained in the first weeks after co-infection, the GC response was less than that in mice infected with Nb only. Nb infection resulted in some abrogation of the longer-term development of anti-STm IgG responses. This suggested that prior Nb infection may modulate the induction of protective antibody responses to vaccination. To assess this we immunized mice with porins, which confer protection in an antibody-dependent manner, before challenging with STm. Mice that had resolved a Nb infection prior to immunization induced less anti-porin IgG and had compromised protection against infection. These findings demonstrate that co-infection can radically alter the development of protective immunity during natural infection and in response to immunization

Zinc or Multiple Micronutrient Supplementation to Reduce Diarrhea and Respiratory Disease in South African Children: A Randomized Controlled Trial

Prophylactic zinc supplementation has been shown to reduce diarrhea and respiratory illness in children in many developing countries, but its efficacy in children in Africa is uncertain.To determine if zinc, or zinc plus multiple micronutrients, reduces diarrhea and respiratory disease prevalence.Randomized, double-blind, controlled trial.Rural community in South Africa.THREE COHORTS: 32 HIV-infected children; 154 HIV-uninfected children born to HIV-infected mothers; and 187 HIV-uninfected children born to HIV-uninfected mothers.Children received either 1250 IU of vitamin A; vitamin A and 10 mg of zinc; or vitamin A, zinc, vitamins B1, B2, B6, B12, C, D, E, and K and copper, iodine, iron, and niacin starting at 6 months and continuing to 24 months of age. Homes were visited weekly.Primary outcome was percentage of days of diarrhea per child by study arm within each of the three cohorts. Secondary outcomes were prevalence of upper respiratory symptoms and percentage of children who ever had pneumonia by maternal report, or confirmed by the field worker.Among HIV-uninfected children born to HIV-infected mothers, median percentage of days with diarrhea was 2.3% for 49 children allocated to vitamin A; 2.5% in 47 children allocated to receive vitamin A and zinc; and 2.2% for 46 children allocated to multiple micronutrients (P = 0.852). Among HIV-uninfected children born to HIV-uninfected mothers, median percentage of days of diarrhea was 2.4% in 56 children in the vitamin A group; 1.8% in 57 children in the vitamin A and zinc group; and 2.7% in 52 children in the multiple micronutrient group (P = 0.857). Only 32 HIV-infected children were enrolled, and there were no differences between treatment arms in the prevalence of diarrhea. The prevalence of upper respiratory symptoms or incidence of pneumonia did not differ by treatment arms in any of the cohorts.When compared with vitamin A alone, supplementation with zinc, or with zinc and multiple micronutrients, did not reduce diarrhea and respiratory morbidity in rural South African children.ClinicalTrials.gov NCT00156832

Severe morbidity and mortality in untreated HIV-infected children in a paediatric care programme in Abidjan, Côte d'Ivoire, 2004-2009

<p>Abstract</p> <p>Background</p> <p>Clinical evolution of HIV-infected children who have not yet initiated antiretroviral treatment (ART) is poorly understood in Africa. We describe severe morbidity and mortality of untreated HIV-infected children.</p> <p>Methods</p> <p>All HIV-infected children enrolled from 2004-2009 in a prospective HIV programme in two health facilities in Abidjan, Côte d'Ivoire, were eligible from their time of inclusion. Risks of severe morbidity (the first clinical event leading to death or hospitalisation) and mortality were documented retrospectively and estimated using cumulative incidence functions. Associations with baseline characteristics were assessed by competing risk regression models between outcomes and antiretroviral initiation.</p> <p>Results</p> <p>405 children were included at a median age of 4.5 years; at baseline, 66.9% were receiving cotrimoxazole prophylaxis, and 27.7% met the 2006 WHO criteria for immunodeficiency by age. The risk of developing a severe morbid event was 14% (95%CI: 10.7 - 17.8) at 18 months; this risk was lower in children previously exposed to any prevention of mother-to-child-transmission (PMTCT) intervention (adjusted subdistribution hazard ratio [sHR]: 0.16, 95% CI: 0.04 - 0.71) versus those without known exposure. Cumulative mortality reached 5.5% (95%CI: 3.5 - 8.1) at 18 months. Mortality was associated with immunodeficiency (sHR: 6.02, 95% CI: 1.28-28.42).</p> <p>Conclusions</p> <p>Having benefited from early access to care minimizes the severe morbidity risk for children who acquire HIV. Despite the receipt of cotrimoxazole prophylaxis, the risk of severe morbidity and mortality remains high in untreated HIV-infected children. Such evidence adds arguments to promote earlier access to ART in HIV-infected children in Africa and improve care interventions in a context where treatment is still not available to all.</p

What zinc supplementation does and does not achieve in diarrhea prevention: a systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Prevention of diarrhea has presented indomitable challenges. A preventive strategy that has received significant interest is zinc supplementation. Existing literature including quantitative meta-analyses and systematic reviews tend to show that zinc supplementation is beneficial however evidence to the contrary is augmenting. We therefore conducted an updated and comprehensive meta-analytical synthesis of the existing literature on the effect of zinc supplementation in prevention of diarrhea.</p> <p>Methods</p> <p>EMBASE^®, MEDLINE ^®and CINAHL^®databases were searched for published reviews and meta-analyses on the use of zinc supplementation for the prevention childhood diarrhea. Additional RCTs published following the meta-analyses were also sought. Effect of zinc supplementation on the following five outcomes was studied: incidence of diarrhea, prevalence of diarrhea, incidence of persistent diarrhea, incidence of dysentery and incidence of mortality. The published RCTs were combined using random-effects meta-analyses, subgroup meta-analyses, meta-regression, cumulative meta-analyses and restricted meta-analyses to quantify and characterize the role of zinc supplementation with the afore stated outcomes.</p> <p>Results</p> <p>We found that zinc supplementation has a modest beneficial association (9% reduction) with incidence of diarrhea, a stronger beneficial association (19% reduction) with prevalence of diarrhea and occurrence of multiple diarrheal episodes (28% reduction) but there was significant unexplained heterogeneity across the studies for these associations. Age, continent of study origin, zinc salt and risk of bias contributed significantly to between studies heterogeneity. Zinc supplementation did not show statistically significant benefit in reducing the incidence of persistent diarrhea, dysentery or mortality. In most instances, the 95% prediction intervals for summary relative risk estimates straddled unity.</p> <p>Conclusions</p> <p>Demonstrable benefit of preventive zinc supplementation was observed against two of the five diarrhea-related outcomes but the prediction intervals straddled unity. Thus the evidence for a preventive benefit of zinc against diarrhea is inconclusive. Continued efforts are needed to better understand the sources of heterogeneity. The outcomes of zinc supplementation may be improved by identifying subgroups that need zinc supplementation.</p

Trace elements in hemodialysis patients: a systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Hemodialysis patients are at risk for deficiency of essential trace elements and excess of toxic trace elements, both of which can affect health. We conducted a systematic review to summarize existing literature on trace element status in hemodialysis patients.</p> <p>Methods</p> <p>All studies which reported relevant data for chronic hemodialysis patients and a healthy control population were eligible, regardless of language or publication status. We included studies which measured at least one of the following elements in whole blood, serum, or plasma: antimony, arsenic, boron, cadmium, chromium, cobalt, copper, fluorine, iodine, lead, manganese, mercury, molybdenum, nickel, selenium, tellurium, thallium, vanadium, and zinc. We calculated differences between hemodialysis patients and controls using the differences in mean trace element level, divided by the pooled standard deviation.</p> <p>Results</p> <p>We identified 128 eligible studies. Available data suggested that levels of cadmium, chromium, copper, lead, and vanadium were higher and that levels of selenium, zinc and manganese were lower in hemodialysis patients, compared with controls. Pooled standard mean differences exceeded 0.8 standard deviation units (a large difference) higher than controls for cadmium, chromium, vanadium, and lower than controls for selenium, zinc, and manganese. No studies reported data on antimony, iodine, tellurium, and thallium concentrations.</p> <p>Conclusion</p> <p>Average blood levels of biologically important trace elements were substantially different in hemodialysis patients, compared with healthy controls. Since both deficiency and excess of trace elements are potentially harmful yet amenable to therapy, the hypothesis that trace element status influences the risk of adverse clinical outcomes is worthy of investigation.</p

A systematic review of the reporting of Data Monitoring Committees' roles, interim analysis and early termination in pediatric clinical trials

<p>Abstract</p> <p>Background</p> <p>Decisions about interim analysis and early stopping of clinical trials, as based on recommendations of Data Monitoring Committees (DMCs), have far reaching consequences for the scientific validity and clinical impact of a trial. Our aim was to evaluate the frequency and quality of the reporting on DMC composition and roles, interim analysis and early termination in pediatric trials.</p> <p>Methods</p> <p>We conducted a systematic review of randomized controlled clinical trials published from 2005 to 2007 in a sample of four general and four pediatric journals. We used full-text databases to identify trials which reported on DMCs, interim analysis or early termination, and included children or adolescents. Information was extracted on general trial characteristics, risk of bias, and a set of parameters regarding DMC composition and roles, interim analysis and early termination.</p> <p>Results</p> <p>110 of the 648 pediatric trials in this sample (17%) reported on DMC or interim analysis or early stopping, and were included; 68 from general and 42 from pediatric journals. The presence of DMCs was reported in 89 of the 110 included trials (81%); 62 papers, including 46 of the 89 that reported on DMCs (52%), also presented information about interim analysis. No paper adequately reported all DMC parameters, and nine (15%) reported all interim analysis details. Of 32 trials which terminated early, 22 (69%) did not report predefined stopping guidelines and 15 (47%) did not provide information on statistical monitoring methods.</p> <p>Conclusions</p> <p>Reporting on DMC composition and roles, on interim analysis results and on early termination of pediatric trials is incomplete and heterogeneous. We propose a minimal set of reporting parameters that will allow the reader to assess the validity of trial results.</p