Non-communicable diseases (NCDs), also known as chronic diseases of lifestyle, cause the greatest burden of disease globally. The major risk factors for NCDs are hypertension, hyperglycaemia, high cholesterol, tobacco smoking, alcohol abuse, overweight/obesity and physical inactivity. NCDs in South Africa are increasing in black South Africans with the transition from rural to urban areas. The transitions have resulted in a change in lifestyle. Regular moderate intensity physical activity (PA) has many health benefits and decreases the risk for NCDs. PA is often determined by means of questionnaires, motion sensors (pedometers and accelerometers), heart rate and accelerometry combined. Within the South African context PA has traditionally been determined with internationally composed questionnaires adapted for South Africa. In South Africa the relationship between PA and risk factors for NCDs has not been investigated in populations in transition, and limited information on the relationship between change in PA and the change in risk factors in a South African population is available. The objectives of this study was to determine the correlation between the adapted Baecke physical activity questionnaire and the International Physical Activity Questionnaire (short version) (IPAQ-S), the changes in PA and how the changes relate to changes in BMI, and finally the relationship between the changes in PA and the changes in the risk factors for NCDs of black South Africans. The study forms part of the baseline and five year follow-up of the South African leg of the Prospective Urban and Rural Epidemiological (PURE) study. This study is a longitudinal study of which the baseline data was allocated in 2005 and the five year follow-up allocated in 2010. 2 000 participants aged 30 years and older were recruited for the initial study – 1 000 urbanised (from Ikageng), and 1 000 rural black adults (from Ganyesa, Moswana and Tlakgameng). Data, including the PA questionnaires (Baecke & IPAQ-S) were collected by a specialised multidisciplinary team. After signing an informed consent form, questionnaires were completed during individual interviews and conducted by extensively trained fieldworkers in the language of the participants’ choice. The variables used in this study were anthropometric measurements, blood pressure, serum lipids and fasting blood glucose. BMI was calculated from the body weight divided by the height squared. Statistical analysis was performed using SPSS for windows (Version 21.0). Descriptive statistics were performed to determine the characteristics of the participants. The relationship between Baecke and IPAQ-S was determined by means of a partial correlation adjusting for age and BMI. Linear regression analyses were used to determine the relationship between the changes in PA (dependent variable) and BMI (predictor variable) and then adjusted for gender and age. Where a significant relationship was observed (in the case of setting, urban versus rural) separate analyses were performed for the rural and urban participants; likewise the relationship between the changes in PAI (dependant variable) and the change in the risk factors for NCDs (predictor variable) was determined by means of linear regression analysis, and also adjusted for gender, change in age and setting (urban/rural). The results from this study indicated that a weak but significant relationship was found between the Baecke and IPAQ-S (Spearman r = 0.243; p = 0.00) when adjusted for age and BMI. Significant differences were found between rural and urban participants for age and BMI in 2005, where the urban participants where older and reported a higher BMI compared to the rural participants. Rural women gained significantly more weight than the urban women. The PAI in the urban participants increased from 2005 (6.40 ± 1.84) to 2010 (7.50 ± 1.40), but decreased in rural participants from 2005 (8.21 ± 1.48) to 2010 (5.10 ± 1.54). Change in BMI was significantly inverse associated with change in PA for the urban population after adjusting for gender, setting (rural/urban) and change in age (β = -0.10; p = 0.004). Significant differences were found for resting systolic blood pressure (SBP) for the rural (129.72 ± 23.30) and urban (137.33 ± 25.14) participants as well as the diastolic blood pressure (DBP) of rural (86.16 ± 14.48) and urban (89.28 ± 14.46), fasting glucose of rural (4.88 ± 1.23) and urban (5.10 ± 1.86), triglycerides of rural (1.21 ± 0.64) and urban (1.38 ± 0.92) and physical activity index (PAI) of rural (8.21 ± 1.48) and urban (6.40 ± 1.84) in 2005. There were significant changes in the high density lipoprotein cholesterol (HDL-C) and in the low density lipoprotein cholesterol (LDL-C). Although the overall PAI decreased from 2005 (7.30 ± 1.90) to 2010 (6.46 ± 1.85), it increased in urban participants (6.40 ± 1.84 – 7.50 ± 1.40) and decreased in rural participants (8.21 ± 1.48 – 5.10 ± 1.54). A significant negative relationship between changes in PAI and changes in blood pressure (systolic and diastolic), total cholesterol and LDL-cholesterol was found when adjusted for gender. When changes in PA and changes in risk factors were separated according to gender, a significant negative relationship was found between PA and diastolic blood pressure (β -0.63; p 0.02) in the male population, and a significant negative relationship for females between PA and systolic blood pressure (β -1.05; p 0.002), diastolic blood pressure (β -0.59; p 0.003), total cholesterol (β -0.05; p 0.01) and LDL-cholesterol (β -0.07; p 0.00). In conclusion, the study found that the low but significant correlation between PAI assessed with the Baeck questionnaire and IPAQ-S makes both questionnaires applicable for the South African context, however the Baecke questionnaire is based on various domains for PA, while the IPAQ-S report on time spent in physical activity. Over the 5-year period PA decreased in this black South African population with a concomitant increase in BMI. Biological risk factors for NCDs increased from 2005 to 2010. The change in PA was inversely related to changes in total blood pressure. Future in PA interventions would be beneficial in the management of hypertension in the at risk South African black population. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014

No description available.

No description available.

Magister Public Health - MPH / South Africa is undergoing epidemiological transition characterised by large shifts in dietary patterns. Modern societies seem to have adopted a ―Western diet‖ which is high in saturated fats, sugar, salt, refined foods and low in fibre. Poor dietary intake practices are closely linked to the development of non-communicable diseases (NCDs), which are the leading causes of death globally. Among the prevalent NCDs is diabetes, which is closely associated with obesity. South Africa is not spared the widespread increase in diabetes and obesity, in both rural and urban settings. Aim: The aim of this study is to investigate the prevalence and the risk factors of diabetes and obesity, with special focus on dietary intake practices, among black urban South Africans residing in Cape Town, Western Cape, and black rural South Africans residing in Mount Frere, Eastern Cape. Methods: A quantitative, cross-sectional descriptive study design was utilised which involved the analysis of baseline data collected in 2009 and 2010 from the Cape Town cohort of the Prospective Urban and Rural Epidemiological (PURE) study. The study included a total of 2038 black South Africans, men and women, rural and urban, who were from the ages 35 to70 years. The PURE adult questionnaire was used to collect socio-demographic, anthropometric and medical history data. Dietary intake data was also collected using a standardised food frequency questionnaire from the PURE study. Data analysis was done using SPSS (version 25.0) and Stata (version 14.0) statistical programmes. Data on nutrient intake was summarised as means and standard deviations. Pearson correlation and multivariate regression analysis were performed to assess the relationship between dietary intake practices, diabetes, and obesity, and to predict risk.

Magister Scientiae (Nutrition Management) - MSc(NM) / Introduction: Non-communicable diseases (NCDs) are among the leading causes of premature death in South Africa. As is the case with many countries in transition, in South Africa the burden of pre-NCDs such as overweight and obesity is increasing. The aim of this mixed method study was to gain an understanding on the knowledge, attitudes, practices and perceptions and related factors of primary and secondary school teachers in Limpopo Province of South Africa regarding nutrition related non-communicable diseases (NR-NCDs). Methodology: A mixed method approach, parallel convergent study design was used to collect both qualitative and quantitative data from a group of randomly selected public school teachers in Rakwadu Circuit, Limpopo, with due consideration of the ethical issues involved. For the quantitative inquiry, a previously validated structured questionnaire was adapted to collect data from 114 teachers, while 2 Focus Group Discussions (FGDs) were conducted by the researcher to collect the qualitative data. Information collected included teachers‟ dietary practices, physical activity levels and their knowledge, attitudes and perceptions towards nutrition related non-communicable diseases. Each of these variables had a number of questions which were scored and a mean score for each participant was obtained. Anthropometric measurements collected included Body Mass Index (BMI) and waist circumference (WC).

Rift Valley fever (RVF) is a disease endemic to Africa, which has recently spread outside of Africa to the Arabian Peninsula. Rift Valley fever virus (RVFV) is the causative agent of RVF and manifests as severe hepatitis, encephalitis and haemorrhagic fever, resulting in mortality in approximately 1% of human cases. RVFV also affects agriculture as it causes high mortality rates in young ruminants (>90% in new-born lambs) and is associated with high levels of abortions, which results in devastating economic losses. RVFV is a single-stranded RNA virus with a genome comprising of three separate genetic elements referred to as the Large (L), Medium (M) and Small (S) segments. The negative sense L segment encodes an RNA-dependent RNA polymerase (RdRp) while the M segment encodes two glycoproteins, Gn and Gc, and two non-structural proteins, NSm1 and NSm2. The glycoproteins are important for viral entry, genome packaging and mature virion formation as well as being the main antigen for the elicitation of neutralising antibodies by humoral immunity. The NSm proteins are required for mosquito vector transmission and preventing viral-induced apoptosis in host cells. The ambisense S segment encodes in the positive orientation a non-structural (NSs) gene, and in the negative orientation the nucleocapsid (N) gene. NSs is an important virulence factor involved in subverting host defences and the loss of NSs results in a highly attenuated RVFV infection. N is required for RNA synthesis and encapsidation of viral genomes. There are currently very few treatments in the early stages of development and vaccines for RVFV are not readily available. The overall lack of therapeutic strategies for RVFV urges novel therapeutic development such as RNA interference (RNAi). Endogenous RNAi is triggered by dsRNA and is involved in gene regulation through sequence specific suppression of target mRNA. Therapeutic RNAi exploits the RNAi pathway to facilitate targeted degradation of viral genes and has been applied effectively to the inhibition of a number of viruses that cause chronic and acute infections. There are fewer studies that have used RNAi to inhibit highly pathogenic viruses. Efficacy has been demonstrated against Ebola virus, Lassa virus and Dengue fever virus, which suggests applicability to the inhibition of RVFV. In this thesis, short hairpin RNAs (shRNAs) were generated to target the NSs, N and M genes of RVFV, which are important proteins in the viral life cycle. To determine the knockdown efficacy of the shRNAs, HEK293 cells were transiently transfected with the shRNAs and a vector expressing the respective shRNA gene target fused to a luciferase reporter. The reporter levels were assessed using a dual-luciferase assay and several shRNAs were selected for further characterisation as a result of effective target knockdown. Consequently, the shRNAs reduced the levels of expressed FLAG-tagged NSs, N and M encoded proteins, which were detected using western blot analysis. ShRNAs directed against NSs were shown to disrupt this protein’s function to result in alleviation of pathogenic properties. Specifically, NSs was shown to suppress the transcription levels of a luciferase reporter as well as prevent the activation of an IFN-β promoter. When the shRNAs were transiently transfected into HEK293 cells, they were able to reverse NSs-induced suppression in the reporter assays. Furthermore, NSs is cytotoxic as determined by observing cell morphology under transmitted light microscopy, which was quantified using a MTT viability assay and cells that subsequently received anti-NSs shRNAs had improved viability. This class of anti-pathogenic shRNAs should be able to down-regulate NSs in vivo and attenuate RVFV virulence. However, NSs is not essential for viral replication and as a result of the aggressive pathology of haemorrhagic RVF, essential structural genes were targeted to investigate shRNAs with anti-replicative properties. ShRNAs directed against N were transfected 24 hrs prior to infection with RVFV. The inhibition of viral replication was determined by collecting supernatant over 3 days and measuring the levels of N antigen using an ELISA. The shRNAs demonstrated effective suppression of RVFV but N antigen was detected at 72 hrs post-infection, which suggested that the shRNAs were overwhelmed by the virus. A series of shRNAs against M were subsequently tested and the anti-M shRNAs effectively suppressed viral replication in cultured cells over an extended 96 hr experiment, demonstrating that M is a good target for RNAi-mediated inhibition of RVFV. In this thesis, the potential of RNAi-based therapeutics against RVFV was demonstrated and these data contribute to the growing knowledge that RNAi should be developed further as a potential treatment for haemorrhagic fever viruses. Finally, some DNA viruses such as HBV form cellular reservoirs from which new virus can be produced and the DNA is resistant to RNAi-mediated inhibition. RVFV is an RNA virus with an acute infection, which makes it more susceptible to RNAi and an excellent target for this particular therapeutic modality.

Diarrhea is the second leading cause of death in children under-5; it kills more children than HIV/AIDS, measles, and malaria combined. Despite this significant health burden, our ability to anticipate and prepare for diarrhea outbreaks remains limited. Precipitation and temperature variability have been shown to affect diarrhea dynamics and therefore contribute to outbreak predictions, but the observed environment-diarrhea relationships are complex and context-specific, depending on local pathogen distribution, host population behavior, and physical environments. To date, studies in sub-Saharan Africa, where the burden of under-5 diarrhea is particularly high, are limited due to sparse diarrheal disease surveillance data. In this dissertation, we leverage unique under-5 diarrhea incidence data to explore the effects of meteorological variability on childhood diarrhea incidence and develop a real-time forecasting system for diarrheal disease in Botswana, where diarrhea remains an important cause of childhood morbidity and mortality. The study focuses in Chobe District, which has an annual dry (April – September) and wet (October – March) season, during which the Chobe River, the primary source of drinking water in the region, floods. Weekly cases of under-5 diarrhea in Chobe District exhibit strong seasonal dynamics with biannual outbreaks occurring during the wet and the dry season. In Chapter 1, we show that wet season diarrhea incidence is strongly associated with increased rainfall and Escherichia coli concentrations in the Chobe River, while dry season incidence is associated with declines in Chobe River flood height and increased total suspended solids in the river. In Chapter 2, we confirm the existence of an El Niño-Southern Oscillation teleconnection with southern Africa by demonstrating that La Niña conditions are associated with cooler temperatures, increased rainfall, and higher flooding in Chobe District during the wet season. In turn, we show that La Niña conditions lagged 0-5 months are associated with higher than average incidence of under-5 diarrhea in the early wet season (December – February). In Chapter 4, we develop and test an epidemiological forecast model for childhood diarrheal disease in Chobe District. The prediction system uses a compartmental susceptible-infected-recovered-susceptible (SIRS) model coupled with Bayesian data assimilation to infer relevant epidemiological parameter values and generate retrospective forecasts. The model system accurately forecasts diarrhea outbreaks up to six weeks before the predicted peak of the outbreak, and prediction accuracy increases over the progression of the outbreak. Many forecasts generated by the model system are more accurate than predictions made using only historical data trends. This dissertation work is an important step forward in our understanding of the links between proximal and distal climatic variability and childhood diarrhea in arid regions of sub-Saharan Africa. Furthermore, it advances methods for generating accurate long-term and short-term forecasts of under-5 diarrhea. We demonstrates the potential use of ENSO data, which are publicly available, to prepare for and mitigate diarrheal disease outbreaks in a low-resource setting up to 5 months in advance, and develop a model-inference system that can generate accurate predictions during an outbreak. Deaths caused by diarrhea are preventable using low-cost treatments. Hence, accurate predictions of diarrhea outbreak magnitudes could help healthcare providers and public health officials prepare for and mitigate the significant morbidity and mortality resulting from diarrhea outbreaks.

Community-associated methicillin-resistant Staphylococcus aureus has been an increasing public health problem since its emergence in the 1990s and incarcerated populations are at disproportionately high-risk for colonization and infection. However, few studies have investigated why levels of S. aureus remain endemic in correctional settings in the absence of an outbreak. The overall objective of this dissertation was to evaluate S. aureus transmission in two maximum-security prisons using a molecular epidemiologic approach and data collected on over 2,700 inmates from 2009 – 2013. The objective of this dissertation was met using three aims. First, a systematic literature review was conducted to identify studies that used social network analysis (SNA) to evaluate infectious disease transmission via non-sexual/non-injection drug use contact pathways to detect influences of social networks on disease risk. Results of the review demonstrated that SNA approaches in infectious disease epidemiology are flexible and can be used to enhance traditional contact investigations, reveal granular patterns of transmission, evaluate influences of high-risk behaviors and activities, and identify both protective and causal effects resulting from context-specific social interactions. Second, changes in the distribution and diversity of S. aureus isolates with increasing length of incarceration were assessed. The results revealed some evidence for S. aureus transmission based on greater representation of certain strains; however, the genetic diversity of S. aureus was high regardless of length of time served. Third, the influence of social interactions among prison inmates on S. aureus colonization status was examined using SNA. The results showed that S. aureus colonized inmates were more likely to spend time in social groups and that the mechanisms of transmission differed for men and women. For women, the association was driven by being centrally located in the social network and for men it was driven by higher proportions of colonized inmates in close proximity. Overall, the results of this dissertation support the hypothesis that S. aureus is transmitted within prisons as a result of direct skin-to-skin contact and/or exposure to contaminated environmental surfaces. However, the results also demonstrate that, in the absence of an outbreak, S. aureus transmission within prisons is low indicating that endemic levels of S. aureus are primarily maintained by the constant introduction of clones into prisons from jails and the community.

范家偉. / 論文(博士)--香港中文大學歷史學部, 1997. / 附參考文獻. / 中英文摘要. / Available also through the Internet via Dissertations & theses @ Chinese University of Hong Kong. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Fan Jiawei. / Lun wen (Bo shi)--Xianggang Zhong wen da xue li shi xue bu, 1997. / Fu can kao wen xian. / Zhong Ying wen zhai yao.

Submitted by Natalia Vieira (natalia.vieira@famerp.br) on 2016-05-30T21:52:31Z No. of bitstreams: 1 lucianasouzajorge_dissert.pdf: 1193713 bytes, checksum: 87fe8f7c70497cf298249a806a3219b4 (MD5) / Made available in DSpace on 2016-05-30T21:52:31Z (GMT). No. of bitstreams: 1 lucianasouzajorge_dissert.pdf: 1193713 bytes, checksum: 87fe8f7c70497cf298249a806a3219b4 (MD5) Previous issue date: 2005-07-04 / Since the 1970´s Group B Streptococcus (GBS) or Streptococcus agalactiae has been considered the leading cause of early-onset neonatal disease. Even after the adoption of strategies for intrapartum antimicrobial prophylaxis (IAP) in the 1990´s, it has been observed GBS to be responsible for approximately 70% of neonatal mortality. The objective of this study was to establish prevalence of GBS colonization among pregnant women and parturients treated at Hospital de Base de Sao Jose do Rio Preto and the perinatal factors of risk related to maternal colonization. A descriptive and retrospective study was carried out. One hundred and twenty-two patients (pregnant women and parturients) selected for risk factors were submitted to collection of vaginal and rectal swabs which were then inoculated to specific Todd-Hewitt broth used to GBS identification. Statistical analysis of data was performed using logistic regression and Pearson 2 test or Fisher´s test, as appropriated. Prevalence of GBS maternal colonization was 24.6%, revealing statistically significant evidence among women with school education between 8 and 11 years (p=0.029) and those referring having had previous infant born with neonatal disease (p=0.025). The prevalence of GBS colonization of patients admitted at the studied Hospital Obstetrics Department points out the necessity for the institution to have an IAP protocol in order to avoid indiscriminate use of antimicrobial therapy for newborns admitted at the Neonatal Intensive Therapy Unit (NITU) and reduce the rate of neonatal morbidity and mortality. / Desde a década de 70, o Streptococcus do Grupo B (SGB) ou Streptococcus agalactiae é considerado a principal causa de doença neonatal precoce. Mesmo com a padronização de estratégias de profilaxia antimicrobiana intraparto (PAI) nos anos 90, tem sido verificado que o SGB é responsável por aproximadamente 70% de mortalidade neonatal. O objetivo deste estudo foi conhecer a prevalência da colonização por SGB entre gestantes e parturientes atendidas no Hospital de Base de São José do Rio Preto e os fatores de risco perinatais envolvidos na colonização materna. Foi realizado um estudo descritivo e retrospectivo em 122 gestantes ou parturientes incluídas por fatores de risco, as quais foram submetidas à coleta de material vaginal e anal, inseridos posteriormente ao caldo de crescimento específico Todd-Hewitt, que é utilizado para identificação dos SGB. A análise estatística dos dados foi realizada por regressão logística e pelo teste de quiquadrado Pearson ou teste de Fisher, quando recomendado. A prevalência de colonização materna por SGB foi de 24,6%, mostrando evidência estatisticamente significante entre mulheres com grau de escolaridade entre 8 a 11 anos (p=0,029) e que referiram história de filho anterior com doença neonatal (p=0,025). A prevalência da colonização por SGB entre gestantes e parturientes atendidas no serviço de obstetrícia no hospital estudado mostra a necessidade da instituição de um protocolo de PAI, a fim de evitar a utilização indiscriminada de antimicrobianos para recém nascidos admitidos na Unidade de Terapia Intensiva Neonatal (UTIN) e reduzir as taxas de morbidade e mortalidade neonatal.