Magister Scientiae Dentium - MSc(Dent) / Introduction: Dental fluorosis is a developmental disturbance of enamel that results from ingestion of high amounts of fluoride during tooth mineralization. Drinking water remains the main source of fluoride. Other sources of fluoride include infant formula, vegetables; canned fish as well as early, improper utilization of fluoridated toothpastes in children. Knowledge of risk factors in the causation of dental fluorosis may improve strategies to prevent dental fluorosis. Objective: To determine the prevalence of dental fluorosis among children aged 12-15 years old in Athi River sub-county, Machakos County, Kenya and assess the level of knowledge on risk factors for dental fluorosis among their parents. Methodology: This was a descriptive study with an analytic component. A total of 281 children aged 12-15 years attending public primary schools within Athi River sub-county, Machakos County were included. A self-administered questionnaire was send to parents for sociodemographic characteristics and oral health practices. Children whose parents consented were examined and dental fluorosis scored according to the Thylstrup and Fejerskov index. Fourty randomly selected children were requested to bring water samples from their homes. Retail stores located in the area were visited for purchase of six different brands of bottled water. These samples were sent to a certified laboratory for fluoride analysis and reported in milligrams of fluoride per litre. Data analysis: Data was entered into SPSS version 20 and analysed for means, ANOVA of means and chi-square test of significance for categorical variables. All tests for significance were set at 95% confidence level (α≤0.05). Results: A total of 314 self-administered questionnaires were send to parents together with consent forms for their children's participation in the study. Two hundred and eighty six responded positively, giving a response rate of 91%. The overall prevalence of dental fluorosis among children aged 12-15 years was 93.4% with only 6.6% (n=19) recording a TFI score of 0. About one quarter 70(24.4%) of children had severe fluorosis with TFI scores of ≥5. The mean TFI score for all children was 3.09 (SD=2.0), with males recording a mean TF score of 3.01 (SD=2.11) and females a mean TF score of 3.16 (SD=1.88). Out of 44 water samples analysed, 29 (65.9%) had a fluoride content of less than 0.6mg/l, 5 (11.4%) had fluoride content of 0.7 - 1.5mg/l while 10 (22.7%) of samples had a fluoride content ≥1.5mg/l. The highest fluoride content recorded was 9.3mg/l, with another sample reflecting 8.9mgF/l. Three of the bottled water samples had a fluoride content of less than 0.6mg/l, while the other half of the bottled water reported 0.7 - 0.8mg/l fluoride. A majority (87.8%) of parents indicated that they had noticed children with brown staining of their permanent teeth in their community. About 80% of parents thought dental fluorosis was caused by salty water, while only 12.9% correctly identified water with high fluoride content as being responsible for the discolored teeth. Conclusion: Although about one in five water sources sampled had fluoride content of ≥1.5mg/l, the prevalence of dental fluorosis in this community was very high. Parental knowledge on the risk factors for dental fluorosis was low. Further research is necessary to identify the water distribution networks to provide sound evidence for engaging with the county authorities on provision of safe drinking water to the community.

Magister Scientiae (Physiotherapy) - MSc(Physio) / Soccer is the most popular sport in the world with 270 million active soccer players. Among all sports, soccer causes many injuries in high school players. Soccer injuries are due to the influence of intrinsic risk factors like age, the immature musculoskeletal system, previous injuries, overuse injuries, inadequate rehabilitation, aerobic fitness, body size, limb dominance, flexibility, muscle strength, muscle imbalance and reaction time, level of competition, skill level and extrinsic risk factors like use of protective equipment, playing surface and shoes type. Information on soccer injuries can help in preparing proper preventing programs in high schools. Despite the importance in providing enough information, no study has been done on soccer related injuries in Rwandan high schools. The aim of this study was to determine the epidemiology of, and risk factors to soccer related injuries among male high school student soccer players in Kigali, Rwanda. A cross-sectional retrospective quantitative study design using quantitative method is used. Among 30 high schools identified in Kigali only 12 had male soccer teams. All 12 teams participated in this study with 336 soccer players. A self-administered questionnaire using closed-ended questions was used. SPSS software program 19.0 version was used for data analysis. Descriptive statistics were used to analyze the data. Inferential statistics such as cross-tabulations were used to test for significant risk factors contributing to injuries. Chi-square test was used to test for significant relationship between risk factors and injuries at level of significance p-value<0.05. Permission and ethical clearance was requested from Senate Research Grant and Study Leave Committee (UWC) and the Ministry of Education. Informed consent were signed by participants and the parents of those who were under 18 years. Participation was voluntary and participants could withdraw from the study at any time. The injury prevalence was high during matches (77.5%) compared to training (32.5%).The ankle was the most affected joint (26.6%). Defenders were the most affected players (22.6%). The majority of injuries were the result of collision (24.2%). The majority of participants did not perform warming-up and cooling-down exercise during training (71.2%) and during matches (56.3%). Most of participants did not wear protective equipment (61.6%). Of those who did, only 7% wore it always. A significant number of injuries occurred because no protective equipment was worn. Only 33.7% soccer players received professional injury management. Of the 33.7% that received professional management, only 39% were medically cleared to return to play. The results of the study confirm that many Rwandan high school soccer players sustain more injuries during match sessions. The poor performance of warm-up and cooling-down, starting age, surface condition and not using protective equipment are significant risk factors for injury in male soccer players in high school. The study highlighted the need to start prevention efforts at club level in order to curtail the high injury prevalence at provincial and national levels.

Background: The cholera epidemic experienced in the province of KwaZulu-¬Natal between August 2000 and July 2001 resulted in 105, 000 reported cases of cholera and 220 human deaths. Objectives: The primary objective of this study was to make comparison between districts with cholera and districts with no cholera in rural KwaZulu-Natal on the basis of known risk factors for cholera and diarrhoeal diseases. Comparison was made with regards to key factors such as the prevalence of diarrhoeal diseases, the provision of safe water supply, ownership and effective utilization of sanitary facilities, knowledge and practice on water purification and prevention of cholera. Methods and materials: This was a descriptive, cross- sectional, ecological and comparative study among households of KwaZulu-Natal. The communities were stratified into two groups. One group had cholera (Group 1) and the other group (Group 2) had no cholera. Thirty communities were selected by systematic random selection from each of the two groups. From each community, eligible households were selected using simple random sampling technique. Trained field workers used a pre-tested questionnaire to collect data during the months of November and December 2001. Statistical procedures such as two-sample tests on means and proportions, Pearson's chi-square tests of association, odds ratios, binary logistic regression analysis, sensitivity tests, specificity tests and ROC (receiver of characteristics) analysis were used for data analysis. Results: A total of 1420 households from both groups were included in the study. The response rate for Group 1 and Group 2 was 84%,92%. Female respondents (70%) predominated male respondents (30%). Tap water supply was less common in Group 1 (54%) than in Group 2 (72%), (p< 0.05). A higher percentage of households in Group 1 (27%) used dam or river water compared to Group 2 (20%) (p<0.05). Household knowledge on water purification by boiling was (71%) in Group 1 and (87%) (p<0.05) in Group 2.38% of households in Group 1 practiced water purification by using disinfectant JIK. The corresponding figure for Group 2 was 50% (p<0.05). Groups 1 and 2 were similar with respect to ownership of toilets (84% and 85% respectively). Groups 1 and 2 showed a marked difference with respect to utilization of toilet facilities by all family members (70% and 89% respectively). The prevalence of diarrhoeal diseases for Group 1 was higher (14.3%) (p<0.05) than the Group 2 was (11.1%). Factors found to be helpful for protection against diarrhoeal diseases were the boiling of water (OR=0.41, 95% CI, 0.19-0.90) and the use of disinfectant JIK (OR=0.45, 95% CI, 0.19-0.94). The study also showed that the use of dam or river water was significantly associated with diarrhoeal diseases (OR=2.92, 95% CI, 1.06-7.80). Conclusion: The results showed that there was significant difference between the two groups of households in regards to basic provision of safe water, knowledge and practice of good hygiene, ownership and effective utilization of sanitary facilities. Findings from this study could be useful as baseline information for future planning, monitoring and evaluation of ongoing programmes. / Dissertation (MSc(Epidemiology))--University of Pretoria, 2005. / School of Health Systems and Public Health (SHSPH) / unrestricted

Background: This study identified, addressed and validated risk factors that can be measured in the peri-traumatic period which may eventually be used in predicting the development of traumatic stress. Many people in South Africa possibly suffer from Posttraumatic Stress Disorder (PTSD) if we consider the extent of trauma exposures that is apparent within the South African population. Traumatised individuals are at risk but may remain undiagnosed and untreated. It makes sense for first line and primary health care practitioners (i.e., not highly qualified psychological practitioners) to screen for risk since they have the initial contact with trauma individuals. A relatively easy screening instrument that can be administered time efficiently would be useful in this regard. The principles of this instrument are that it needs to be objectively measurable, quick and easy to administer. No consistent measure geared towards identifying risk factors in such a manner immediately post trauma currently exists in South Africa. Objectives: The overall aim was to start a process of designing a psychometric instrument that is valid in predicting the development of traumatic stress. Since this is the initial stage of constructing a new measure, content validity was of utmost importance. It became imperative to ensure that items were not only relevant and appropriate, but also accurate and capable in identifying at-risk individuals. The proposed end goal is to develop effective identification strategies in South Africa geared towards helping victims of traumatic events. Method: A pilot psychometric questionnaire was compiled using three major international reviews, South African research on known risk factors, and literature on PTSD risk assessment considerations. This preliminary assembled item pool was used as a departure point and evaluated quantitatively as well as qualitatively by expert reviewers who have research and/or clinical experience with PTSD in a South African context. Their feedback resulted in either the omission or the modification of certain items; for some items, further exploration was recommended. The questionnaire was further scrutinised and modified accordingly after qualitative interviews with and critical feedback from the intended administrators or primary health care professionals, namely Registered Counsellors (RCs) and/or nursing staff from a participating general government hospital and a non-government organisation. Findings: Expert reviewers did not agree consistently across all the items. At times they rated certain items as relevant according to the necessity of the information rather than with regards to the relevance of the content of the item – in terms of prediction of PTSD. It was also observed that intended administrators did not always agree with expert reviewers.

Background - Current guidelines suggest that all cancer patients with venous thrombosis be treated with long-term low molecular weight heparin. Whether treatment strategies should vary according to clinical characteristics remains unknown. // Systematic review - A systematic review was performed to determine current understanding of the association between malignancy characteristics in patients with cancer-associated VTE and the risk of VTE recurrence. Four retrospective and 6 prospective studies were included. They suggest that lung cancer, metastases, and adenocarcinomas confer an increased the risk of recurrence and breast cancer a low risk. // Survey - I performed survey to evaluate thrombosis experts’ opinion about the low risk of VTE recurrence they would consider acceptable for patients with cancer- associated thrombosis 103 specialists participated. 80% of respondents agreed that a risk of recurrent VTE during anticoagulation below 7% is low enough. 92% agreed that a CPR that categorizes risk of recurrence is relevant. // Retrospective Study - I performed a single retrospective cohort study to assess the feasibility of derivation of a CPR that stratifies VTE recurrence risk in patients with cancer–associated thrombosis. The study included 543 patients. A multivariate analysis selected female, lung cancer and prior history of VTE as high risk predictors and breast cancer and stage I disease as low risk. // Conclusion - Patients with cancer-associated thrombosis do have varying risks of recurrent VTE depending on clinical characteristics.

The association between pain and depression is well documented across various populations, but not in puerperal women. This study examined the association of childbirth pain with postpartum depression (PPD) in a nationally representative sample of Canadian women. Data from the Canadian Maternity Experiences Survey (n=6421) was used. Multivariate logistic regressions and partial proportional odds models were fitted and included socio-demographic, obstetric, health, psychological, and psychosocial factors. Chronic pain sufferers at mean 7.3 months postpartum had adjusted odds of PPD of 2.4 (95% CI: 1.6, 3.6) compared to women without pain. Adjusted odds of PPD increased with the number of areas of chronic pain, reaching 4.2 (95% C.I.: 0.7, 25.0) for 3 or more areas. Immigration, obesity, cesarean section and social support increased the strength of the association while smoking and the use of pain relief were protective effect modifiers. Persistent postpartum pain is a major risk factor for PPD.

In exploring current responses to crime, particularly youth involvement in gangs, this thesis examines two approaches: Crime Prevention through Social Development (CPSD) and risk-based prevention. The former is associated with the provision of socially-designed measures to address and eliminate the risk factor associated with persistent offending. The latter, however, refers to the implementation of risk management and statistical assessment to manage the risk factor associated with persistent offending. In light of these two approaches, this thesis examines a debate which purported that crime prevention practices has wholly shifted away from an emphasis on CPSD towards risk-based prevention. This thesis also examines the opposing debate which explains that CPSD and risk-based prevention have emerged into a balanced approach. Taking into account 19 youth gang prevention projects in Canada, the above debates are investigated. Drawing from the analysed project, this thesis concludes that, the crime prevention practices of the analyzed projects significantly rely on risk-based prevention. As a result, the approaches of CPSD still exist in rhetoric and in practice however, its influence on crime prevention initiatives is very limited. Hence, current approaches neither reflect a total shift away from CPSD nor a balanced approach.

Vector-borne diseases, such as those transmitted by mosquitoes, pose a significant public health concern in many countries worldwide. In this thesis, I explored the role of a number of risk factors defined at multiple scales on vector-borne disease prevalence, focusing on malaria and arboviral infections in several regions of North-Eastern Tanzania, with the principal aim of improving the overall diagnosis of febrile illness in this region. First, I investigated the influence of household-wealth on prevalence of malaria and arboviral infections using principal component analysis (PCA), and then described the methodological challenges associated with this statistical technique when used to compute indices from smaller datasets. I then employed a multilevel modelling approach to simultaneously incorporate household-level anthropogenic factors and village-level environmental characteristics to investigate key determinants of Anopheles malaria vector density among rural households. These analyses provided methodologically rigorous approaches to studying vector-borne diseases at a very fine-scale and also have significant public health relevance as the research findings can assist in guiding policy decisions regarding surveillance efforts as well as inform where and when to prioritize interventions.

In this work the topic of breast cancer treated more generally and mainly focused on risk factors for the development. The theoretical part describes the general knowledge about breast cancer as a stage or treatment. The practical part is to have clarified the risk factors that have some bearing on the diagnosis of breast cancer. What level are involved in the probability of occurrence? Can we eliminate them? As a comparison of risk factors examined in the Czech Republic, England, Australia and the United States.

Magister Scientiae (Physiotherapy) - MSc(Physio) / Physical inactivity is one of the leading risk factors for major non-communicable diseases, which contribute substantially to the global burden of chronic diseases, disability and death. The burden of disability, morbidity and mortality, attributable to non-communicable diseases, is currently enormous in the developed countries and is increasingly growing in the developing countries. The purpose of this study was to investigate the relationship between participation in physical activity and health risk behaviours among high school students in the Mtwara region, Tanzania. The objectives of this study were to identify the physical activity levels among high school students in Mtwara region, Tanzania, to identify health risk behaviours among the above mentioned high school students, to identify the factors that influenced them to engage in health risk behaviours and to establish the relationship between physical activity and health risk behaviours. / South Africa