Mark E Engel

University of Cape Town | UCT · Department of Medicine

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. Met...

Invasive group A streptococcal (Strep A) infections occur when Streptococcus pyogenes, also known as beta-hemolytic group A Streptococcus, invades a normally sterile site in the body. This article provides guidelines for establishing surveillance for invasive Strep A infections. The primary objective of invasive Strep A surveillance is to monitor t...

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.We performed qua...

Background: Integrase strand transfer inhibitors (InSTIs) decrease HIV plasma viral load faster than other antiretroviral classes. More rapid viral load decline has been associated with higher risk of immune reconstitution inflammatory syndrome (IRIS). There are conflicting reports on the association between InSTI and IRIS. We performed a systemat...

Background Our study aimed to systematically identify RHD stakeholders and categories of stakeholders to consider when developing a scorecard that reflects a broad stakeholder input. Method We used the Schiller et al.(2013) framework to identify RHD stakeholders and stakeholder categories in Tanzania and Uganda. The process involved identifying st...

Background: This article aims to explain the rationale and design for developing an evidence-based scorecard to monitor country-level implementation of the 71st World Health Assembly resolution on rheumatic fever and rheumatic heart disease (RHD) in Africa. Rationale: A scorecard provides a simple and reliable tool for tracking progress over tim...

Introduction: Peripartum cardiomyopathy (PPCM) remains a major contributor to maternal morbidity and mortality worldwide. The disease is associated with various complications, which occur predominantly during the early stages of the disease. Adverse outcomes include decompensated heart failure, thromboembolic complications, arrhythmias and death....

Introduction: Human papillomavirus (HPV) is an established risk factor for oropharyngeal squamous cell carcinoma, regardless of a history of other known risk factors such as alcohol and tobacco. While cases of HPV-related oral squamous cell carcinoma (OSSC) are increasing in the USA, Europe and South Central Asian countries, little is known about t...

Importance Rheumatic heart disease (RHD), a sequela of rheumatic fever characterized by permanent heart valve damage, is the leading cause of cardiac surgery in Africa. However, its pathophysiologic characteristics and genetics are poorly understood. Understanding genetic susceptibility may aid in prevention, control, and interventions to eliminate...

Objectives This systematic review evaluated the evidence for the effectiveness of Photodynamic therapy (PDT) in treating oral fungal infections, as an alternative to conventional antifungal medications. Methods Five randomized control trials (168 participants) comparing the treatment of oral fungal infections using met with our inclusion criteria....

Background Group A Streptococcus (Strep A) is an important cause of mortality and morbidity globally. This bacterium is responsible for a range of different infections and post-infectious sequelae. Summarising the current knowledge of Strep A transmission to humans will address gaps in the evidence and inform prevention and control strategies. The...

Background Androgenetic alopecia (AGA) is the most common form of non‐scarring alopecia in humans. Several studies have used different laboratory models to study the pathogenesis and interventions for AGA. These study models have proved beneficial and have led to the approval of two drugs. However, the need to build on existing knowledge remains by...

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are preventable complications of group A streptococcus (GAS) infection that is endemic in many countries. Prevention of ARF/RHD can be initiated at primordial, primary, and secondary levels. There has been a recent reappraisal of the role of primary prevention targeting early diagnosis a...

Background Group A streptococcal (GAS) pharyngitis has traditionally been considered the sole precursor of acute rheumatic fever (ARF). Evidence from Australia, however, suggests that GAS skin infections may contribute to the pathogenesis of ARF. A missing piece of evidence is the incidence of sore throat and GAS pharyngitis in this setting. We con...

Objective: To summarise the accuracy of handheld echocardiography (HAND) which, if shown to be sufficiently similar to that of standard echocardiography (STAND), could usher in a new age of rheumatic heart disease (RHD) screening in endemic areas. Design: Systematic review and meta-analysis. Data sources: PubMed, Scopus, EBSCOHost and ISI Web...

Background: National and international political commitments have been made recently on rheumatic heart disease (RHD), a preventable heart condition that is endemic in low-resource countries. To inform best practice and identify evidence gaps, we assessed the effectiveness of RHD prevention and control programmes and the extent and nature of their...

Background: An effective vaccine against Bordetella pertussis was introduced into the Expanded Programme on Immunisation (EPI) by WHO in 1974, leading to a substantial global reduction in pertussis morbidity and mortality. In low- and middle-income countries (LMICs), however, the epidemiology of pertussis remains largely unknown. This impacts nega...

Low vaccine coverage is of grave public health concern, particularly in developing countries where epidemiological data are often absent. To inform vaccine development for group A Streptococcus (GAS), we report on the epidemiology of the M protein emm clusters from GAS infections in Africa, where GAS-related illnesses and their sequelae, including...

Objective: Community-based peer and community health worker-led diabetes self-management programs (COMP-DSMP) can benefit diabetes care, but the supporting evidence has been inadequately assessed. This systematic review explores the nature of COMP-DSMP in low- and middle-income countries' (LMIC) primary care settings and evaluates implementation s...

Congenital heart disease (CHD) is the most common birth defect globally and coarctation of the aorta (CoA) is one of the commoner CHD conditions, affecting around 1/1800 live births. CoA is considered a CHD of critical severity. Unfortunately, the prognosis for a child born in a low and lower-middle income country (LLMICs) with CoA is far worse tha...

Background An emm -cluster based system was proposed as a standard typing scheme to facilitate and enhance future studies of Group A Streptococcus (Strep A) epidemiological surveillance, M protein function and vaccine development strategies. We provide an evidence-based distribution of Strep A emm clusters in Africa and assess the potential coverag...

Background: Political instability, economic sanctions and substandard quality of health care negatively affect tuberculosis (TB) control in the Middle East and North Africa (MENA) region. Aims: We aimed to elucidate factors contributing to delays in TB diagnosis and treatment in MENA countries. Methods: Two reviewers independently appraised el...

Hypertension and obesity are the most important modifiable risk factors for cardiovascular diseases, but their association is not well characterized in Africa. We investigated regional patterns and association of obesity with hypertension among 30 044 continental Africans. We harmonized data on hypertension (defined as previous diagnosis/use of ant...

Genetic association studies in rheumatic heart disease (RHD) have the potential to contribute toward our understanding of the pathogenetic mechanism, and may shed light on controversies about RHD etiology. Furthermore, genetic association studies may uncover biomarkers that can be used to identify susceptible individuals, and contribute toward deve...

Objectives: Group A β-hemolytic streptococcus (GAS), also known as Streptococcus pyogenes, is responsible for an annual 600 million cases of acute pharyngitis globally, with 92% of those infections occurring in low-resource settings. Further knowledge of the acute streptococcal pharyngitis burden in low resource settings is essential if serious po...

Objectives It remains unclear whether computer-assisted instruction (CAI) is more effective than other teaching methods in acquiring and retaining ECG competence among medical students and residents. Design This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data s...

Background: The prevalence of group A streptococcal (GAS) disease is estimated at >18.1 million cases with an incidence of >1.78 million cases per year. While a significant cause of mortality and morbidity on the global scale, the burden of GAS disease in Africa is unknown. We conducted a systematic review on the prevalence of GAS disease among ch...

The development of a vaccine for group A streptococcus (GAS) is of paramount importance given that GAS infections cause more than 500,000 deaths annually across the world. This prospective passive surveillance laboratory study evaluated the potential coverage of the M protein-based vaccine currently under development. While a number of GAS strains...

Introduction: A common concern in African genomic research is that such work may cause, or increase, stigma associated with particular diseases or population groups. While there is some evidence suggesting that genetic attribution of disease might impact stigma, there exists no evidence for the situation in African populations. With increasing gen...

Objective The aim of this study was to summarise the results from existing studies reporting on the effectiveness of the introduction of violence and injury observatories (VIOs). Design This is a systematic review and meta-analysis study. Data sources We searched multiple electronic databases including but not limited to PubMed, PsycINFO, SCOPUS,...

A systematic review (PROSPERO 2018 CRD42018117037 Available from: http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018117037 Review) addressing the question: 'What is the prevalence of, and factors associated with the prevalence of extensively drug resistant tuberculosis in Africa as reported from January 2006 to May 2018?'

Introduction Rheumatic heart disease (RHD) is a preventable chronic condition affecting the valves of the heart. RHD prevention and care programmes have historically originated in more developed countries, implemented in a targeted (or vertical) manner and evaluated using non-controlled approaches. Taking a broad view of the integration of RHD acti...

Background Globally, rheumatic heart disease (RHD) is a major contributor to the burden of cardiovascular disease. Major gaps in RHD prevention and treatment have been documented at all levels of health systems in low- and middle-income countries. Task sharing is an approach that could prove effective in remediating bottlenecks in RHD-related care....

Background: An increasing body of empirical evidence suggests that early intervention has positive outcomes for parents of children with neurodevelopmental disabilities. Parental self-efficacy has been used as an outcome measure in some empirical studies; however, there is a lack of evidence of the impact of parent training programmes on parenting...

Objective Digoxin is widely used in patients with rheumatic heart disease (RHD) despite a lack of data on its impact on clinical outcomes. We aimed to determine the association of digoxin use on clinical outcomes in patients with RHD. Methods We performed a retrospective analysis of the association of digoxin use with mortality at 2 years in a lar...

Background: The large global burden of rheumatic heart disease (RHD) has come to light in recent years following robust epidemiologic studies. As an operational research component of a broad program aimed at primary and secondary prevention of RHD, we sought to determine the current prevalence of RHD in the country's capital, Lusaka, using a moder...

Objectives: To evaluate the major risk factors for adverse short and long term outcomes in patients with active native valve infective endocarditis needing cardiac surgery and to validate the EuroSCORE II in our cohort of patients. Methods: We retrospectively studied 149 patients who underwent native valve surgery for infective endocarditis in Jun...

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 whe...

Background: The burden of disease caused by group A streptococcus (GAS) in Africa is largely unknown. The aim of this study was to determine the incidence of invasive (iGAS) and non-invasive GAS (non-iGAS) infections in patients attending the public health sector of South Africa. Methods: iGAS and non-iGAS infection was defined as GAS isolated in...

Background: Rheumatic heart disease (RHD) is a major public health problem in low- and middle-income countries (LIMCs), with a paucity of high-quality trial data to improve patient outcomes. Investigators felt that involvement in a recent large, observational RHD study impacted positively on their practice, but this was poorly defined. Aim: The...

Introduction Rheumatic heart disease (RHD) is a preventable and treatable chronic condition which persists in many developing countries largely affecting impoverished populations. Handheld echocardiography presents an opportunity to address the need for more cost-effective methods of diagnosing RHD in developing countries, where the disease continu...

Introduction Rheumatic heart disease (RHD) remains an important cause of cardiovascular morbidity and mortality globally due to weak health systems in many countries. RHD can be effectively prevented and managed; however, RHD-related interventions have not been widely adopted in countries with severe human resource constraints. Task sharing is a re...

Introduction Although ECG interpretation is an essential skill in clinical medicine, medical students and residents often lack ECG competence. Novel teaching methods are increasingly being implemented and investigated to improve ECG training. Computer-assisted instruction is one such method under investigation; however, its ef cacy in achieving bet...

The establishment of violence and injury observatories elsewhere has been found to reduce the burden within a relatively short period. Currently no integrated system exists in South Africa to provide collated data on violence, to allow for targeted interventions and routine monitoring and evaluation.This research seeks to identify if bringing multi...

Background: The burden of disease caused by group A streptococcus (GAS) in Africa is largely unknown. The aim of this study was to determine the incidence of invasive (iGAS) and non-invasive GAS (non-iGAS) infections in patients attending the public health sector of South Africa. Methods: iGAS and non-iGAS infection was defined as GAS isolated in c...

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 epi...

Introduction Latent tuberculosis infection (LTBI) remains a major public health problem and one of the major contributors to the pool of active tuberculosis cases. The true burden of LTBI in Africa is not known. Early modelling studies estimate that over 33% of the world’s population is infected with latent tuberculosis. We propose conducting a sys...

Background: Reported long-term outcome measures vary greatly between studies in Fontan patients making comprehensive appraisal of mortality hazard challenging. We sought to create a clinical risk score to assist monitoring of Fontan patients in the outpatient setting. Methods: A systematic review was conducted to evaluate risk factors for long-t...

Opinion statement Early recognition of group A streptococcal pharyngitis and appropriate management with benzathine penicillin using local clinical prediction rules together with validated rapi-strep testing when available should be incorporated in primary health care. A directed approach to the differential diagnosis of acute rheumatic fever now i...

Background: Rheumatic heart disease (RHD) is an important and preventable cause of cardiovascular disease. Objectives: As part of a recent RHD initiative in Uganda and Tanzania, we systematically reviewed group A streptococcal disease (GAS), acute rheumatic fever (ARF), and RHD in these countries. Methods: Using a systematic review and meta-an...

Rheumatic heart disease (RHD) is an important cause of disability and death in low- and middle-income countries. However, evidence-based interventions have not been implemented systematically in many countries. We present a RHD Needs Assessment Tool (NAT) that can be used at country or regional levels to systematically develop and plan comprehensiv...

Background Despite an ageing Fontan population, data on late outcomes are still scarce. Reported outcome measures and determinants vary greatly between studies making comprehensive appraisal of mortality hazard challenging. Methods We conducted a systematic review to evaluate causes and factors associated with late mortality in patients with Fonta...

Background: Existing clinical decision rules (CDR) to diagnose group A streptococcal (GAS) pharyngitis have not been validated in sub-Saharan Africa. We developed a locally applicable CDR while evaluating existing CDRs for diagnosing GAS pharyngitis in South African children. Methods: We conducted a prospective cohort study and enrolled 997 chil...

Background: There are few contemporary data on the mortality and morbidity associated with rheumatic heart disease or information on their predictors. We report the 2-year follow-up of individuals with rheumatic heart disease from 14 low- and middle-income countries in Africa and Asia. Methods: Between January 2010 and November 2012, we enrolled...

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, Af...

When new evidence comes to light, it compels us to contemplate the implications of such evidence for health policy and practice. This article examines recent research evidence on the prevalence of asymptomatic rheumatic heart disease (RHD) in South Africa and considers the implications for the Integrated School Health Programme (ISHP). RHD is still...

Rheumatic fever is caused by an abnormal immune reaction to group A streptococcal infection. Secondary prophylaxis with antibiotics is recommended for people after their initial episode of rheumatic fever to prevent recurrent group A streptococcal infections, recurrences of rheumatic fever and progression to rheumatic heart disease. This secondary...