OpenUCT :: Browsing by Author "Engel, Mark E"

Browsing by Author "Engel, Mark E"

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Open Access
AFROStrep (SA): a surveillance system for group A streptococcal infection in South Africa
(2018) Barth, Dylan Dominic; Engel, Mark E; Mayosi, Bongani M
BACKGROUND AND AIMS OF THE THESIS: Group A β-haemolytic Streptococcus (GAS) also known as Streptococcus pyogenes, is responsible for a wide range of invasive and non-invasive GAS diseases. Prevalence and incidence data on GAS from developing countries are largely lacking when compared with industrialised nations. This thesis sought to (1) establish the South African arm of the AFROStrep biorepository and clinical database for patients with invasive and non-invasive GAS infection, (2) identify and summarize all published studies of laboratory-confirmed GAS infection in Africa, (3) describe, from national laboratory data, the incidence of invasive and non-invasive GAS in South Africa and, (4) conduct a prospective, surveillance study in order to determine the molecular epidemiology of GAS in Cape Town, South Africa over a 12-month period. METHODS: A systematic review was conducted on population-based studies reporting on the prevalence of laboratory-confirmed GAS infection among patients living in Africa (Study 1). A retrospective study of the incidence of GAS infection was conducted on data obtained from the National Health Laboratory Service between 2003 – 2015 (Study 2). The AFROStrep registry and biorepository (based in Cape Town) was established and through passive surveillance, laboratory confirmed invasive and non-invasive GAS cases were collected over a 12-month period. The molecular analysis of invasive and non-invasive infection was determined using emm type sequencing to provide insight into vaccine development (Study 3). RESULTS AND DISCUSSION: The pooled prevalence of GAS pharyngitis in Africa was determined to be 21% (95% CI, 17% to 26%). The incidence rates of laboratory-confirmed non-invasive GAS infection in the South African public sector appears to have declined over the last 13 years. Given the possibility that the lower incidence of invasive and non-invasive GAS infection found in our study is due to infrequent submission of specimens for microbiological culture by health practitioners, our findings may be an underestimate of the true burden of disease in South Africa. In our prospective surveillance study, 46 different emm types were identified. The most prevalent emm types were M76 (16% of isolates), M81 (10%), M80 (6%), M43 (6%), and M183 (6%) and were almost evenly distributed between invasive and non-invasive GAS isolates. When compared against the putative 30-valent vaccine under development, four of our most prevalent emm types are not included; vaccine coverage (i.e. vaccine type and non-vaccine type-killing) for non-invasive and invasive GAS infection in our setting was 60% and 59% respectively, notably lower than coverage in developed countries. CONCLUSION: This work provides evidence for a significantly high prevalence of GAS pharyngitis in Africa. While GAS surveillance in South Africa indicates a declining incidence of GAS disease in parts of the country over the last thirteen years, the findings may be an underestimate of the true burden of disease, demonstrating the need for accurate and comprehensive surveillance of GAS in South Africa. Finally, this research showed a low potential vaccine coverage in our setting and thus, emphasises the need for a reworking of the potential vaccine formulation to improve coverage in areas where the burden of disease is high.
Open Access
The burden of antenatal heart disease in South Africa: a systematic review
(BioMed Central Ltd, 2012) Watkins, David; Sebitloane, Motshedisi; Engel, Mark E; Mayosi, Bongani
BACKGROUND: Maternal mortality in South Africa is rising, and heart conditions currently account for 41 per cent of indirect causes of deaths. Little is known about the burden of heart disease in pregnant South Africans. METHODS: We systematically reviewed the contemporary epidemiology and peripartum outcomes of heart disease in South African women attending antenatal care. Searches were performed in PubMed, ISI Web of Science, the EBSCO Africa-Wide database, the South African Union Catalogue, and the Current and Completed Research database (South Africa). References of included articles were also hand-searched. Studies reporting epidemiologic data on antenatal heart disease in South Africa were included. Data on morbidity and mortality were also collected. RESULTS: Seven studies were included in the systematic review. The prevalence of heart disease ranged from 123 to 943 per 100,000 deliveries, with a median prevalence of 616 per 100,000. Rheumatic valvular lesions were the commonest abnormalities, although cardiomyopathies were disproportionately high in comparison with other developing countries. Peripartum case-fatality rates were as high as 9.5 per cent in areas with limited access to care. The most frequent complications were pulmonary oedema, thromboembolism, and major bleeding with warfarin use. Perinatal mortality ranged from 8.9 to 23.8 per cent, whilst mitral lesions were associated with low birth weight. Meta-analysis could not be performed due to clinical and statistical heterogeneity of the included studies. CONCLUSION: Approximately 0.6 per cent of pregnant South Africans have pre-existing cardiac abnormalities, with rheumatic lesions being the commonest. Maternal and perinatal morbidity and mortality continue to be very high. We conclude this review by summarising limitations of the current literature and recommending standard reporting criteria for future reports.
Open Access
Burden of pneumocystis pneumonia in HIV-infected adults in sub-Saharan Africa: a systematic review and meta-analysis
(BioMed Central, 2016-09-09) Wasserman, Sean; Engel, Mark E; Griesel, Rulan; Mendelson, Marc
Abstract Background Seroprevalence data and clinical studies in children suggest that the burden of pneumocystis pneumonia (PCP) in Africa may be underestimated. We performed a systematic review to determine the prevalence and attributable mortality of PCP amongst HIV-infected adults in sub-Saharan Africa. Methods We searched Pubmed, Web of Science, Africa-Wide: NiPAD and CINAHL, from Jan 1 1995 to June 1 2015, for studies that reported the prevalence, mortality or case fatality of PCP in HIV-infected adults living in sub-Saharan African countries. Prevalence data from individual studies were combined by random-effects meta-analysis according to the Mantel-Haenszel method. Data were stratified by clinical setting, diagnostic method, and study year. Results We included 48 unique study populations comprising 6884 individuals from 18 countries in sub-Saharan Africa. The pooled prevalence of PCP among 6018 patients from all clinical settings was 15 · 4 % (95 % CI 12 · 9–18 · 0), and was highest amongst inpatients, 22 · 4 % (95 % CI 17 · 2–27 · 7). More cases were identified by bronchoalveolar lavage, 21 · 0 % (15 · 0–27 · 0), compared with expectorated, 7 · 7 % (4 · 4–11 · 1), or induced sputum, 11 · 7 % (4 · 9–18 · 4). Polymerase chain reaction (PCR) was used in 14 studies (n = 1686). There was a trend of decreasing PCP prevalence amongst inpatients over time, from 28 % (21–34) in the 1990s to 9 % (8–10) after 2005. The case fatality rate was 18 · 8 % (11 · 0–26 · 5), and PCP accounted for 6 · 5 % (3 · 7–9 · 3) of study deaths. Conclusions PCP is an important opportunistic infection amongst HIV-infected adults in sub-Saharan Africa, particularly amongst patients admitted to hospital. Although prevalence appears to be decreasing, improved access to antiretroviral therapy and non-invasive diagnostics, such as PCR, are needed.
Open Access
Burden of pneumocystis pneumonia in HIV-infected adults in sub-Saharan Africa: protocol for a systematic review
(BioMed Central Ltd, 2013) Wasserman, Sean; Engel, Mark E; Mendelson, Marc
BACKGROUND: Reports from Africa have suggested that pneumocystis pneumonia (PCP) is a less important cause of morbidity than in the developed world. However, more recent studies have shown high seroprevalence rates of P. jirovecii in healthy individuals with HIV as well as high rates of clinical disease in African children. This suggests that PCP may be more common in Africa than was previously recognised. Understanding the contribution of PCP to disease in HIV-infected individuals in sub-Saharan Africa (SSA) has important implications for diagnosis, management and resource allocation. We therefore propose to conduct a systematic review and meta-analysis in order to investigate the burden of PCP in this population.METHODS AND DESIGN:We plan to search electronic databases and reference lists of relevant articles published from 1995 to May 2013 using broad terms for pneumocystis, HIV/AIDS and sub-Saharan Africa. Studies will be included if they provide clear diagnostic criteria for PCP and well-defined study populations or mortality data (denominator). A novel quality score assessment tool has been developed to ensure fidelity to inclusion criteria, minimise risk of selection bias between reviewers and to assess quality of outcome ascertainment. This will be applied to eligible full-text articles. We will extract data using a standardised form and perform descriptive and quantitative analysis to assess PCP prevalence, mortality and case fatality, as well as the quality of included studies. This review protocol has been published in the PROSPERO International Prospective Register of systematic reviews, registration number CRD42013005530.DISCUSSION:Our planned review will contribute to the diagnosis and management of community-acquired pneumonia in HIV-infected individuals in SSA by systematically assessing the burden of PCP in this population. We also describe a novel quality assessment tool that may be applied to other prevalence reviews.
Open Access
Conducting a meta-ethnography of qualitative literature: Lessons learnt
(BioMed Central Ltd, 2008) Atkins, Salla; Lewin, Simon; Smith, Helen; Engel, Mark E; Fretheim, Atle; Volmink, Jimmy
BACKGROUND:Qualitative synthesis has become more commonplace in recent years. Meta-ethnography is one of several methods for synthesising qualitative research and is being used increasingly within health care research. However, many aspects of the steps in the process remain ill-defined.DISCUSSION:We utilized the seven stages of the synthesis process to synthesise qualitative research on adherence to tuberculosis treatment. In this paper we discuss the methodological and practical challenges faced; of particular note are the methods used in our synthesis, the additional steps that we found useful in clarifying the process, and the key methodological challenges encountered in implementing the meta-ethnographic approach.The challenges included shaping an appropriate question for the synthesis; identifying relevant studies; assessing the quality of the studies; and synthesising findings across a very large number of primary studies from different contexts and research traditions. We offer suggestions that may assist in undertaking meta-ethnographies in the future.SUMMARY:Meta-ethnography is a useful method for synthesising qualitative research and for developing models that interpret findings across multiple studies. Despite its growing use in health research, further research is needed to address the wide range of methodological and epistemological questions raised by the approach.
Open Access
Consumption of Aloe to improve health outcomes in adults with irritable bowel syndrome: A systematic review and meta-analysis
(2019) Fong, Francisco J; Engel, Mark E; Setshedi, Mashiko
PART A is a research protocol which describes the background and proposed methodology of this systematic review and meta-analysis. This section details the quantitative and qualitative methods to be used when analysing the effect of Aloe in the treatment of patients with irritable bowel syndrome (IBS). PART B is an extended literature review which expands on some of the topics raised in the background section of the protocol. A more in-depth explanation of the epidemiology of IBS, is presented, as well as the strengths and limitations of current treatment options in order to understand the context around the proposed research. PART C presents this research in the form of a journal manuscript in a format suitable for submission to Plos ONE. This manuscript includes a background to the research followed by the results section which is then discussed. Lastly, implications for clinical practice are posited and suggestions for further research are offered.
Open Access
Data-independent acquisition mass spectrometry in severe rheumatic heart disease (RHD) identifies a proteomic signature showing ongoing inflammation and effectively classifying RHD cases
(2022-03-22) Salie, M T; Yang, Jing; Ramírez Medina, Carlos R; Zühlke, Liesl J; Chishala, Chishala; Ntsekhe, Mpiko; Gitura, Bernard; Ogendo, Stephen; Okello, Emmy; Lwabi, Peter; Musuku, John; Mtaja, Agnes; Hugo-Hamman, Christopher; El-Sayed, Ahmed; Damasceno, Albertino; Mocumbi, Ana; Bode-Thomas, Fidelia; Yilgwan, Christopher; Amusa, Ganiyu A; Nkereuwem, Esin; Shaboodien, Gasnat; Da Silva, Rachael; Lee, Dave C H; Frain, Simon; Geifman, Nophar; Whetton, Anthony D; Keavney, Bernard; Engel, Mark E
Background Rheumatic heart disease (RHD) remains a major source of morbidity and mortality in developing countries. A deeper insight into the pathogenetic mechanisms underlying RHD could provide opportunities for drug repurposing, guide recommendations for secondary penicillin prophylaxis, and/or inform development of near-patient diagnostics. Methods We performed quantitative proteomics using Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectrometry (SWATH-MS) to screen protein expression in 215 African patients with severe RHD, and 230 controls. We applied a machine learning (ML) approach to feature selection among the 366 proteins quantifiable in at least 40% of samples, using the Boruta wrapper algorithm. The case–control differences and contribution to Area Under the Receiver Operating Curve (AUC) for each of the 56 proteins identified by the Boruta algorithm were calculated by Logistic Regression adjusted for age, sex and BMI. Biological pathways and functions enriched for proteins were identified using ClueGo pathway analyses. Results Adiponectin, complement component C7 and fibulin-1, a component of heart valve matrix, were significantly higher in cases when compared with controls. Ficolin-3, a protein with calcium-independent lectin activity that activates the complement pathway, was lower in cases than controls. The top six biomarkers from the Boruta analyses conferred an AUC of 0.90 indicating excellent discriminatory capacity between RHD cases and controls. Conclusions These results support the presence of an ongoing inflammatory response in RHD, at a time when severe valve disease has developed, and distant from previous episodes of acute rheumatic fever. This biomarker signature could have potential utility in recognizing different degrees of ongoing inflammation in RHD patients, which may, in turn, be related to prognostic severity.
Open Access
Does direct observation of antiretroviral therapy improve outcomes for HIV/AIDS patients compared to non-observed therapy?: A systematic review and meta-analysis of randomized-controlled trials
(2009) Ford, Nathan; Engel, Mark E
Highly active antiretroviral therapy (HAART) has dramatically affected the course of HIV disease, resulting in a significant reduction in AIDS-related morbidity and mortality in both developed and developing countries.
Open Access
The effect of distance to health facility on the maintenance of INR therapeutic ranges in rheumatic heart disease patients from Cape Town
(2013) Barth, Dylan Dominic; Engel, Mark E; Mayosi, Bongani
Part A: is the research protocol which outlines the background and the process of this research. This study is a population-based observational study nested within the Groote Schuur Hospital (GSH) cohort of a global study, REMEDY which is a prospective, multicentre, hopital-based registry for rheumatic heart disease (RHD). This study made use of geographical information systems (GIS) as a tool to investigate the effect of distance on the maintenance of INR therapeutic ranges in RHD patients. Part B: elaborates on the background and highlights the importance of this research by exploring the existing theoretical and empirical literature relevant to the topic. It describes the importance of the maintenance of the INR therapeutic range and how geographical factors can influence patient adherence to medication, and how it can act as a barrier to access health care. It provides examples of how GIS has been used to investigate the effect of distance on adherence in other studies. This literature review aimed to establish whether the maintenance of therapeutic ranges in RHD patients on anticoagulant therapy is correlated with the distance travelled from patient's residence to the clinic where INR monitoring takes place. Part C: presents the entire project in a format suitable for journal submission. The background of this research project is summarised and the results are presented and discussed.
Open Access
Effect of distance to health facility on the maintenance of INR therapeutic ranges in rheumatic heart disease patients from Cape Town: No evidence for an association
(BioMed Central, 2015-06-01) Barth, Dylan Dominic; Zühlke, Liesl; Joachim, Alexia; Hoegger, Tyler; Mayosi, Bongani M; Engel, Mark E
Background: Lack of adherence to international normalised ratio (INR) monitoring in rheumatic heart disease (RHD) patients is a contributor to cardio-embolic complications. This population-based observational study investigated whether the distance between home and an INR clinic affects the maintenance of therapeutic INR in RHD patients on warfarin. Methods: Residential addresses, INR clinics, and INR results of patients with RHD were extracted from the Cape Town component of the Global Rheumatic Heart Disease Registry (REMEDY) database. Addresses of homes and INR clinics were converted to geographical coordinates and verified in ArcGIS 10®. ArcGIS 10® and Google Maps® were used for spatial mapping and obtaining shortest road distances respectively. The travel distance between the home and INR clinic was correlated with time within therapeutic range (TTR) using the Rosendaal linear interpolation method, and with the fraction of INR within range, based on an average of three INR readings of patients and compared with recommended therapeutic ranges. Results: RHD patients (n=133) resided between 0.2 km and 50.8 km (median distance, 3.60 km) from one of 33 INR clinics. There was no significant difference in the achievement of the therapeutic INR between patients who travelled a shorter distance compared to those who travelled a longer distance (in range = 3.50 km versus out of range = 3.75 km, p=0.78). This finding was the same for patients with mechanical valve replacement (n=105) (3.50 km versus 3.90 km, p=0.81), and native valves (3.45 km versus 2.75 km, p=0.84). Conclusions: There is no association between the maintenance of INR within therapeutic range amongst RHD patients in Cape Town and distance from patients’ residence to the INR clinic.
Open Access
The effectiveness of community-based rehabilitation for providing services to people with stroke with functional limitations and participation restriction : a systematic review and implications
(2010) Naidoo, Lionel Edmund; Engel, Mark E; Maart, Soraya
We conducted a systematic review and meta-analysis of randomised and quasi-randomised trials to determine the effectiveness of community-based rehabilitation versus hospital/institution based rehabilitation in providing rehabilitative services to people with stroke with functional limitations and participation restriction. Data sources: Using a highly sensitive search strategy, duplicate searches were conducted for the following databases from January 1976 to May 2010: MEDLINE via PubMed, African Wide Information via EBSCO, Academic Search Premier via EBSCO, Cochrane CENTRAL, CINAHL, PsycInfo, PEDro. Review methods: Abstracts were scanned in duplicate for all randomised and quasi-randomised trials comparing the effectiveness of community-based rehabilitation with hospital/institution based rehabilitation in providing rehabiliative service to people with stroke with functional limitations and participation restriction. For this review, the primary outcome was functional independence while secondary outcomes included quality of life, physical, psychological and social functioning and, community participation of people with stroke and their caregivers. Results: Twelve randomised controlled trials with 2707 people with stroke were included. Percentage of males included in studies ranged from 42% to 75% and the participants ranged in age from a mean or median of 52 years to 78 years for those receiving the intervention and 55 years to 80 years for control participants. The treatment duration of community-based rehabilitation programmes ranged from three weeks to six months. Overall the meta-analysis found no evidence for the effectiveness of community-based rehabilitation as compared with hospital/institution based rehabilitation with respect to functional outcome (Standardised Mean Difference (SMD) 0.09; 95% Confidence Interval (CI) -0.08 to 0.26) or quality of life (Mean Difference (MD) 1.32; 95% CI -4.30 to 6.93) or carer strain (MD 0.76; 95% CI -0.19 to 1.77). Subgroup analyses at three months showed a significant effect for community-based rehabilitation over hospital/institution based rehabilitation on quality of life (MD 5.00; 95% CI 0.82 to 9.18); however, this effect was not maintained at six months. Cost-effectiveness tended towards a cost reduction associated with community-based rehabilitation.Conclusion: Use of community-based rehabilitation may be associated with positive and negative effects. However, there is currently insufficient supporting evidence to justify the implementation of community-based rehabilitation for stroke rehabilitation. A stronger evidence base is required to adequately inform health policy decisions and guide methods of service delivery to effectively improve stroke patient outcomes.
Open Access
Effectiveness of control measures to prevent occupational tuberculosis infection in health care workers: a systematic review
(BioMed Central, 2018-05-25) Schmidt, Bey-Marrié; Engel, Mark E; Abdullahi, Leila; Ehrlich, Rodney
Background A number of guideline documents have been published over the past decades on preventing occupational transmission of tuberculosis (TB) infection in health care workers (HCWs). However, direct evidence for the effectiveness of these controls is limited particularly in low-and middle-income (LMIC) countries. Thus, we sought to evaluate whether recommended administrative, environmental and personal protective measures are effective in preventing tuberculin skin test conversion among HCWs, and whether there has been recent research appropriate to LMIC needs. Methods Using inclusion criteria that included tuberculin skin test (TST) conversion as the outcome and longitudinal study design, we searched a number of electronic databases, complemented by hand-searching of reference lists and contacting experts. Reviewers independently selected studies, extracted data and assessed study quality using recommended criteria and overall evidence quality using GRADE criteria. Results Ten before-after studies were found, including two from upper middle income countries. All reported a decline in TST conversion frequency after the intervention. Among five studies that provided rates, the size of the decline varied, ranging from 35 to 100%. Since all were observational studies assessed as having high or unclear risk of bias on at least some criteria, the overall quality of evidence was rated as low using GRADE criteria. Conclusion We found consistent but low quality of evidence for the effectiveness of combined control measures in reducing TB infection transmission in HCWs in both high-income and upper-middle income country settings. However, research is needed in low-income high TB burden, including non-hospital, settings, and on contextual factors determining implementation of recommended control measures. Explicit attention to the reporting of methodological quality is recommended. Trial registration This systematic review was registered with PROSPERO in 2014 and its registration number is CRD42014009087 .
Open Access
The Effects of Angiotensin Converting Enzyme Inhibitors (ACE-I) on Human N-Acetyl-Seryl-Aspartyl-Lysyl-Proline (Ac-SDKP) Levels: A Systematic Review and Meta-Analysis
(Public Library of Science, 2015) Mnguni, Ayanda Trevor; Engel, Mark E; Borkum, Megan S; Mayosi, Bongani M
BACKGROUND: Tuberculous pericardial effusion is a pro-fibrotic condition that is complicated by constrictive pericarditis in 4% to 8% of cases. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a ubiquitous tetrapeptide with anti-fibrotic properties that is low in tuberculous pericardial effusion, thus providing a potential mechanism for the heightened fibrotic state. Angiotensin-converting enzyme inhibitors (ACE-I), which increase Ac-SDKP levels with anti-fibrotic effects in animal models, are candidate drugs for preventing constrictive pericarditis if they can be shown to have similar effects on Ac-SDKP and fibrosis in human tissues. Objective To systematically review the effects of ACE-Is on Ac-SDKP levels in human tissues. METHODS: We searched five electronic databases (1996 to 2014) and conference abstracts with no language restrictions. Two reviewers independently selected studies, extracted data and assessed methodological quality. The protocol was registered in PROSPERO. RESULTS: Four studies with a total of 206 participants met the inclusion criteria. Three studies (106 participants) assessed the change in plasma levels of Ac-SDKP following ACE-I administration in healthy humans. The administration of an ACE-I was associated with an increase in Ac-SDKP levels (mean difference (MD) 5.07 pmol/ml (95% confidence intervals (CI) 0.64 pmol/ml to 9.51 pmol/ml)). Two studies with 100 participants further assessed the change in Ac-SDKP level in humans with renal failure using ACE-I. The administration of an ACE-I was associated with a significant increase in Ac-SDKP levels (MD 8.94 pmol/ml; 95% CI 2.55 to 15.33; I 2 = 44%). CONCLUSION: ACE-I increased Ac-SDKP levels in human plasma. These findings provide the rationale for testing the impact of ACE-I on Ac-SDKP levels and fibrosis in tuberculous pericarditis.
Open Access
The effects of angiotensin converting enzyme inhibitors (ACEI) on human N-acetylseryl-aspartyl-lysyl-proline (AcSDKP) levels : a systematic review
(2015) Mnguni, Ayanda Trevor; Engel, Mark E; Mayosi, Bongani M
Background: Tuberculous pericardial effusion is a pro-fibrotic condition that is complicated by constrictive pericarditis in 4-8% of cases. N-acetyl-seryl-aspartyl-lysylproline (Ac-SDKP) is a ubiquitous tetrapeptide with antifibrotic properties that is low in tuberculous pericardial effusion, thus providing a potential mechanism for the heightened fibrotic state. Angiotensin converting enzyme inhibitors (ACEI), which increase Ac-SDKP levels with antifibrotic effects in animal models, are candidate drugs for preventing constrictive pericarditis if they can be shown to have similar effects on AcSDKP and fibrosis in human tissues. Objective: To systematically review the effects of ACEIs on Ac-SDKP levels in human tissues. Methods: We searched five electronic databases (1996-2014) and conference abstracts with no language restrictions. Two reviewers independently selected studies, extracted data and assessed methodological quality. The protocol was registered in PROSPERO.
Open Access
The effects of parent training interventions on parental self-efficacy for parents with young children with an autism spectrum disorder or other developmental disabilities : a systematic review
(2016) Hohlfeld, Ameer Steven-Jörg; Harty, Michal; Engel, Mark E
Background: A leading research priority worldwide is the need to improve the lives of those with disabilities through the effective development of interventions that can be carried out by non-specialists. Recent research has indicated that parent training interventions have shown to benefit both children with, and parents of children with disabilities. Aims: This systematic review sought to assess the effectiveness of interventions aimed at increasing parental self-efficacy levels in parents of young children with developmental disabilities. Methods and Procedures: We conducted a broad literature search across a number of databases to identify all relevant prospective studies meeting our study objective. Articles were selected using predefined criteria and data were extracted onto a purposely-designed data extracted form.
Open Access
Epidemiology of pharyngitis as reported by Zambian school children and their families: implications for demand-side interventions to prevent rheumatic heart disease
(BioMed Central, 2017-07-06) Musuku, John; Lungu, Joyce C; Machila, Elizabeth; Jones, Catherine; Colin, Laurence; Schwaninger, Sherri; Musonda, Patrick; Tadmor, Brigitta; Spector, Jonathan M; Engel, Mark E; Zühlke, Liesl J
Background: Prompt and appropriate treatment of streptococcal pharyngitis decreases the risk of acute rheumatic fever and rheumatic heart disease (RHD). Understanding public perceptions and behaviors related to sore throat is fundamental to inform health programs aimed at eliminating new cases of RHD in endemic regions. We sought to describe the epidemiology of pediatric pharyngitis and its treatment, as reported by children and their parents or guardians in Lusaka, Zambia. Methods: This was a cross-sectional investigation using interviews and written surveys, nested in a school-based RHD prevalence study. Students and their parents were asked to report number of sore throats in the previous 12 months, treatment received, and type and place of treatment. A focused history and physical examination to detect pharyngitis was conducted and children were referred for follow-up as indicated. Results: A total of 3462 students from 47 schools participated in the study, along with their parents or guardians. Six hundred and fifty eight (19%) parents/guardians reported their child had at least one sore throat in the previous year, and 835 (24%) of students reported at least one sore throat in the same time period. Girls were reported to have pharyngitis 50% more often than boys, and also made up two-thirds of the total students treated. Approximately two-thirds of children who had at least one episode of pharyngitis during the previous year were also reported to have received some form of treatment. The majority of treatments were received in government clinics (36.6%) and at home (26.3%). Half of treatments included an antibiotic. Nineteen students (0.5%) had clinically-apparent pharyngitis at screening. Conclusion: Pharyngitis is common among school-aged children and adolescents in Zambia, with females reporting significantly more sore throat episodes than males. Parents/guardians have variable knowledge about the frequency of sore throat in their children, and management of pharyngitis may be suboptimal for many children since more than a quarter were reported to have received treatment without skilled assessment. These results provide insight into current perceptions and practices related to sore throat in Zambia and will be used to design public awareness activities aimed at reducing RHD.
Open Access
Factors associated with patient and health system delay in diagnosis and commencement of treatment for pulmonary tuberculosis in the Middle East and North Africa (MENA): systematic review
(2016) Eltayeb, Dalya; Abdullahi, Leila H; Engel, Mark E
This MPH dissertation undertakes a systematic review on factors associated with patient and health system delay in diagnosing and commencing treatment for pulmonary tuberculosis in Middle East and North Africa (MENA). The dissertation is composed of three main parts: namely parts A, B and C. Part A is the research protocol, which give brief background to research topic and the process of this review. This systematic review aims to assess factors associated with patient and health system delay for diagnosis and initiation of treatment of pulmonary tuberculosis in Middle East and North Africa (MENA). Part B elaborates on the background and highlights the importance of this research by examining the existing theoretical and empirical literature relevant to the topic. Part C presents the entire research project in a format suitable for PLOS journal submission. The background of this research project is summarized and the results are presented and discussed.
Open Access
Genetic susceptibility to acute rheumatic fever: a systematic review and meta-analysis of twin studies
(Public Library of Science, 2011) Engel, Mark E; Stander, Raphaella; Vogel, Jonathan; Adeyemo, Adebowale A; Mayosi, Bongani M
BACKGROUND: Acute rheumatic fever is considered to be a heritable condition, but the magnitude of the genetic effect is unknown. The objective of this study was to conduct a systematic review and meta-analysis of twin studies of concordance of acute rheumatic fever in order to derive quantitative estimates of the size of the genetic effect. METHODS: We searched PubMed/MEDLINE, ISI Web of Science, EMBASE, and Google Scholar from their inception to 31 January 2011, and bibliographies of retrieved articles, for twin studies of the concordance for acute rheumatic fever or rheumatic heart disease in monozygotic versus dizygotic twins that used accepted diagnostic criteria for acute rheumatic fever and zygosity without age, gender or language restrictions. Twin similarity was measured by probandwise concordance rate and odds ratio (OR), and aggregate probandwise concordance risk was calculated by combining raw data from each study. ORs from separate studies were combined by random-effects meta-analysis to evaluate association between zygosity status and concordance. Heritability was estimated by fitting a variance components model to the data. RESULTS: 435 twin pairs from six independent studies met the inclusion criteria. The pooled probandwise concordance risk for acute rheumatic fever was 44% in monozygotic twins and 12% in dizygotic twins, and the association between zygosity and concordance was strong (OR 6.39; 95% confidence interval, 3.39 to 12.06; P<0.001), with no significant study heterogeneity (P = 0.768). The estimated heritability across all the studies was 60%. CONCLUSIONS: Acute rheumatic fever is an autoimmune disorder with a high heritability. The discovery of all genetic susceptibility loci through whole genome scanning may provide a clinically useful genetic risk prediction tool for acute rheumatic fever and its sequel, rheumatic heart disease.
Open Access
Health education interventions to raise awareness of rheumatic fever: a systematic review protocol
(BioMed Central Ltd, 2013) Ramsey, Laura; Watkins, Lauren; Engel, Mark E
BACKGROUND:There is a significant global health burden associated with acute rheumatic fever (ARF) and rheumatic heart disease (RHD), especially in developing countries. ARF and RHD most often strike children and young adults living in impoverished settings, where unhygienic conditions and lack of awareness and knowledge of streptococcal infection progression are common. Secondary prophylactic measures have been recommended in the past, but primary prevention measures have been gaining more attention from researchers frustrated by the perpetual prevalence of ARF and RHD in developing countries. Health education aims to empower people to take responsibility for their own well-being by gaining control over the underlying factors that influence health. We therefore conducted a review of the current best evidence for the use of health education interventions to increase awareness and knowledge of streptococcal pharyngitis and ARF.METHODS AND DESIGN:This article describes the protocol for a systematic review of the effectiveness of health education interventions aimed at increasing awareness and knowledge of the symptoms, causes and consequences of streptococcal pharyngitis, rheumatic fever and/or rheumatic heart disease. Studies will be selected in which the effect of an intervention is compared with either a pre-intervention or a control, targeting all possible audience types. Primary and secondary outcomes of interest are pre-specified. Randomized controlled trials, quasi-randomized trials, controlled before-after studies and controlled clinical trials will be considered. We will search several bibliographic databases (for example, PubMed, EMBASE, World Health Organization Library databases, Google Scholar) and search sources for gray literature. We will meta-analyze included studies. We will conduct subgroup analyses according to intervention subtypes: printed versus audiovisual and mass media versus training workshops.DISCUSSION:This review will provide evidence for the effectiveness of educational components in health promotion interventions in raising public awareness in regard to the symptoms, causes and consequences of streptococcal pharyngitis, ARF and/or RHD. Our results may provide guidance in the development of future intervention studies and programs.
Open Access
Integrating the prevention and control of rheumatic heart disease into country health systems: a systemic review
(2018) Abrams, Jessica; Engel, Mark E; Zühlke, Liesl; Watkins, David A; Abdullahi, Leila
Part A is a research protocol which describes the background and proposed methodology of this systematic review. This section contains the details of quantitative and qualitative methods to be used when analysing rheumatic heart disease (RHD) prevention and care programmes. Part B is a literature review which expands on the protocol. An in-depth explanation of the disease process is presented in order to understand the multiple opportunities for preventing RHD and its precursors. The importance of this research then is highlighted by contextualising RHD programmes within the health system and integrated care. Part C presents the research as a journal manuscript according the BMJ’s instructions for authors. The manuscript includes a brief introduction to the research followed by a summary of the methods and presentation of the results which are then discussed.