Over the past 20 years there has been a clear shift in Peru’s mortality profile towards non-communicable diseases. As part of this transition, childhood overweight and obesity (O&O) has become a growing public health concern. In order to address this challenge, context-specific information is needed concerning prevalence, associated factors and culturally appropriate interventions. To this end, I conducted a mixed methods study using a socio-ecological framework to investigate childhood overweight and obesity in Peru. This study found a prevalence of 19.2% overweight and 8.6% obesity among children aged seven to eight in a pro-poor cohort in Peru. Factors associated with being overweight in this cohort included: a high socioeconomic status, living in metropolitan Lima, an O&O mother, being male and being an only child or having only one sibling. The quantitative analysis highlighted the prevalence in O&O in this population and revealed a number of relationships explored in more depth via interviews and focus group discussions. The qualitative component of this research explored these associations amongst a sub-sample of children, parents and teachers in three distinct geographical regions in Peru. My qualitative research showed that parents, teachers and children are aware of the health implications of childhood overweight and obesity and that they have a sophisticated understanding of the many factors that influence its aetiology. Participants also had many suggestions for ways to address this issue in their community. This information was complemented by a systematic review and meta-analysis of the evidence of childhood O&O interventions that took place in Latin America published between 1990 and 2011. A combination of diet, physical activity and pharmaceutical strategies have shown modest effect on BMI reduction in O&O children, but more evidence is needed for effective population-level prevention strategies. The findings highlight the need for comprehensive, multi-level interventions. Notable intervention components include: kiosco reform, junk food taxation, creation of recreational space and enhancement of school-based physical activity programmes. To accomplish this, communities need to be mobilised and work together with school administration, municipal and national government.

Multiple sclerosis is a complex immune mediated condition of the central nervous system characterized by myelin loss and progressive neurodegeneration. The risk of developing MS is influenced by both genetic and environmental agents and, among them, several lines of evidence support a role for vitamin D deficiency, Epstein-Barr virus (EBV) infection and smoking in the aetiology of this disease. The aim of this work was to further elucidate how nature and nurture act in the causal cascade leading to MS. In chapter 1, I show that the main genetic factor in adult MS (the HLA-DRB1*1501 allele) plays an equally important role in paediatric cases of MS (PMS) and that EBV negative PMS patients represent a separate entity characterized by lower age at disease onset, lower female to male ratio and a trend towards a lower frequency of the HLA-DRB1*1501 allele. In chapter 2, I provide evidence in support of month of birth having a role on MS risk and T cell production and that vitamin D may underlie this effect. In chapter 3 I demonstrate the presence of a link between vitamin D deficiency and the immune response against EBV, whereby the proportion of EBV seropositive MS patients and controls increases with increasing latitude and high dose vitamin D supplementation appears to reduce the level of antibodies against this virus. In chapter 4, I show that MS associated genetic variants are located in genomic regions that exert a regulatory function and are active in immune cell types. In chapter 5, I illustrate how vitamin D receptor binding is also located within active regulatory regions in immune cells and that this is particularly evident near MS associated genes. Finally, in chapter 6, I use chromatin data on more than 100 different cell types and conclude that MS associated genetic variants are particularly active in T helper, T cytotoxic and B cells. Further work is needed to elucidate how genetic and environmental agents play a role in the cause of MS and to develop effective strategies for disease treatment and prevention.

Submitted in partial compliance with the requirements of the Master’s Degree in Technology: Chiropractic, Durban University of Technology, Durban, South Africa, 2016. / Background Headaches affect different proportions of many populations and are experienced by any age, gender or ethnicity group. There is a paucity of data on the prevalence of headaches in South Africa, particularly amongst the university student population. Previous studies have suggested that headaches impact on daily activities as well as family and/or social activities. Studies on the impact of headaches on students are limited. Aim of Study The aim of this research study was to determine the prevalence and impact of primary headaches amongst students at the Durban University of Technology (DUT). Methodology A quantitative descriptive cross sectional survey was used to determine the prevalence of primary headaches in the student population at DUT. A minimum sample size of 384 was calculated using a confidence level of 95% and confidence interval of five percent. All six faculties were included. The course programmes and levels were chosen by multi-stage sampling. Each willing participant was required to sign a written consent form prior to enrolment in the study. Subsequently a self-administered questionnaire was filled out. The International Classification of Headache Disorder Criteria was used to classify primary headaches. All data was captured on an Excel spreadsheet and subsequently analysed using SPSS version 23.0. Results The total of 471 completed questionnaires was received. The prevalence of primary and secondary headaches was similar (50.2%; n = 222 versus 49.8%; n = 220, p = 0.92). More participants suffered from tension type (68.5%; n = 152) headaches compared to migraines (16.2%, n = 36) and mixed migraine and tension type headaches (15.3%, n = 34; p < 0.001). None of the study participants suffered from cluster headaches. Poor vision and stress increased the risk of a headache occurrence. The main relieving factor identified was the use of medication. Other relieving factors reported were sleep and relaxation. There was no correlation between suffering from headaches across the different faculties (p = 0.65), age of the participant (p = 0.77), ethnicity (p = 0.40), marital status (p = 0.84) and gender (p = 0.35). Headaches had a negative impact on the academic activities of the affected participants, including limited concentration and a complete halt to studies. Conclusion Tension type headaches were more prevalent amongst the study population. The impact of headaches limited concentration during tests and examination periods. An increased frequency and intensity of headaches was reported during this period. Family, social or leisure activities were also neglected when a headache occurred. This study adds to the current literature on headache prevalence in the student population. It also highlights that chiropractors are not consulted for headaches by students in the South African context. The chiropractic profession can benefit by tapping into this population. / M

Background Sport parachuting is a dangerous recreational activity for which available literature appears unsatisfactory to form a basis for injury prevention.  Aim Overall: Explore some risk factors in sport parachuting. Study I: Identify fatal incident and injury mechanisms for skydiving (sport parachuting from aircraft). Study II: Identify fatal incident and injury mechanisms for BASE jumping (sport parachuting from fixed objects) for each of the four fixed object types B-A-S-E (building, antenna, span, earth). Study III: Identify non-fatal incident and injury mechanisms for skydiving. Study IV: Evaluate the validity of a compulsory reporting system among active skydivers. Study V: Explore some aspects of the Swedish skydiving culture and its relation to injury risks and injury reporting. Study VI: Describe the mechanism of incident and injury for a free fall shoulder dislocation. Methods Descriptive epidemiological studies of (I) fatal injury events in Swedish skydiving, (II) fatal injury events in BASE jumping worldwide, and (III) non-fatal injury events in Swedish skydiving. Self-report survey of (IV) Swedish skydivers to measure: Sensitivity, as the proportion of injury events fulfilling the reporting criterion that were actually reported; Specificity, as the proportion of false positives in relation to the defined gold standard. Content analysis of (V) Swedish skydiving participant narratives. First-person narrative and free fall video recordings (VI) of one case. Results Overall: Risk factors associated with “free fall” flight of the human body and recreational usage of parachutes were described. Study I: Fatal risk factors in skydiving included student instability in free fall, leading to unstable parachute activation with subsequent line entanglement or parachute activation failure. Unintentional water landings also contributed to fatalities. Every fourth skydiving fatality survived impact and died during transports or in hospitals. Study II: Fatal risk factors in BASE jumping included parachutist free fall instability, miscalculation of free fall acrobatics, deployment failure by the parachutist, pilot chute malfunction and parachute malfunction. In cliff jumping (BASE object type E), parachute opening towards the object jumped with subsequent collision was a frequent factor. Poor visibility, strong or turbulent winds, cold and water also contributed to BASE jumping fatalities. Study III: Non-fatal risk factors in skydiving included experience level and type of student-training system. The lower extremities, spine and shoulders were important regions of injury. The most serious injuries were seen in experienced skydivers. Study IV: The overall sensitivity of the skydiving injury reporting system was 0.37 (95% confidence interval (CI) 0.24-0.51). With non-minor injuries as the target for reporting, the sensitivity was 0.67 (95% CI 0.43-0.85). No significant effect on reporting was found for gender, age, license level, years in the sport, total number of jumps or club affiliation. The specificity was 0.91 (95% CI 0.83-0.95). Study V: It is suggested that Swedish skydiving culture is carried by the local club; not the national association. Skydiving culture at the local drop zone and formal and informal hierarchical structures among skydivers may be what really decides how rules are enforced, risk-taking behavior is seen, and if incidents and injuries are reported. Study VI: The free fall airstream forces were in this case strong enough to dislocate a shoulder joint, which has safety implications that should be considered by participants and medical doctors performing precourse examinations. Conclusion A number of risk factors in sport parachuting are described. Some technological, training and regulatory interventions are suggested to increase safety.

Thesis (MScPhysio (Interdisciplinary Health Sciences. Physiotherapy))--University of Stellenobosch, 2010. / Background: Low back pain (LBP) has a high prevalence worldwide. LBP is significantly associated with a range of poor socio-demographic circumstances which should be addressed in preventive programs. Despite this there is a dearth of information about the prevalence and associated factors among low-income communities in South Africa. It is speculated that the burden of LBP may be most significant in these underprivileged communities. Objective: The objective of this study was to assess the prevalence of LBP among the lowincome communities in the Cape Town Metropole and to establish associated factors in order to make recommendations for management. Study design: A cross-sectional study was conducted among the visitors of eight community health centres (CHCs) in the Cape Town Metropole. Methodology: A new measurement tool was developed based on existing validated outcome measures and initial testing of the psychometric properties of the questionnaire was conducted. The questionnaire was administered to 489 eligible subjects. Descriptive analysis was used to describe the sample and logistic regression analytical techniques were applied to determine associated factors. Main findings: Lifetime prevalence for LBP was 76.49% (n=358). About 37% (n=133) suffered from chronic LBP. LBP was significantly associated with belonging to the black ethnic group, any co-morbidity, poor perceived general health, and any type of pain medication. Lifting weights > 20 kg and kneeling and squatting were physical factors significantly associated with LBP. Severe psychological distress was significantly associated with acute and chronic LBP. Having a better or same perceived general health compared to a year ago, was protective for LBP. Conclusion: LBP has a high prevalence among the low income communities, visiting the CHCs, in the Cape Town Metropole. Multiple factors were associated with LBP, which imply that a tailormade multidisciplinary program addressing lifestyle issues, self management strategies, medication use, chronic diseases and psychosocial factors may be required for this population to combat LBP.

published_or_final_version / abstract / toc / Community Medicine / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Community Medicine / Master / Master of Public Health

published_or_final_version / Community Medicine / Master / Master of Public Health

published_or_final_version / Community Medicine / Master / Master of Public Health

published_or_final_version / Diagnostic Radiology / Master / Master of Philosophy