Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 5 uppsatser.

Errata sheet has been pasted onto the front end-paper. Bibliography: leaves 208-217. Outlines a systematic synthesis and testing of continual sterilization design. Principal aim is to evaluate and develop mathematical models for sterilization, undertake experimental studies for determining thermal inactivation effects on continuous processing of a liquid containing contaminant bacteria and compare the data obtained with those predicted by a selected model.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Nos Ãltimos anos, o Programa Nacional de Controle da HansenÃase tem focado suas aÃÃes em Ãreas geogrÃficas definidas com alta detecÃÃo de casos. Este estudo teve o objetivo de caracterizar padrÃes epidemiolÃgicos, espaciais e temporais da hansenÃase em um agregado de alto risco de transmissÃo, em municÃpios dos estados do MaranhÃo, ParÃ, Tocantins e PiauÃ. Desta forma, foram aplicados diferentes mÃtodos de anÃlise espacial (Descritivo, Abordagem Bayesiana Local, EstatÃstica Scan Espacial) e quantificada a dependÃncia espacial de diversos indicadores epidemiolÃgicos e operacionais da hansenÃase. Em outro estudo, foram identificados o fluxo de pessoas afetadas e os motivos para migraÃÃo apÃs diagnÃstico. No perÃodo de 2001 a 2009, 82.463 casos novos foram detectados no agregado (coeficiente mÃdio de detecÃÃo: 95,9/100mil habitantes ao ano). No resto do Brasil o coeficiente foi 21,0 (RR=4,56, IC 95%: 4,45-4,66; p<0,0001). Houve fluxo direcionado dospacientes com hansenÃase notificados para um municÃpio diferente da sua residÃncia. AraguaÃna, Imperatriz, Marabà e Floriano receberam um nÃmero considerÃvel de casos provenientes dos municÃpios em seu entorno. As capitais SÃo LuÃs, Teresina e BelÃm absorviam tambÃm casos vindos de outros estados. GoiÃnia e BrasÃlia se localizam distante do agregado, mas tÃm destaque pela notificaÃÃo de casos provenientes do agregado. ApÃs o primeiro diagnÃstico, 53,5% dos motivos principais de migraÃÃo foram relacionados a mudanÃas de estilo de vida. AnÃlise Scan Espacial identificou 23 agregados de elevada detecÃÃo de casos novos, a maioria localizados no Parà e MaranhÃo. Estes agregados incluÃram apenas 32% da populaÃÃo, mas 55,4% dos casos novos e 101 (27,1%) municÃpios. TambÃm foram identificados 14 aglomerados significativos para o coeficiente de detecÃÃo em crianÃas e 11 de casos novos com grau 2 de incapacidade/100mil hab. O agregado mais significativo, no centro do MaranhÃo, teve um RR de 2,24 e uma detecÃÃo anual de 10,4 casos com grau 2/100mil hab. O mÃtodo de autocorrelaÃÃo local mostrou superposiÃÃo com Ãreas de alto risco identificadas pelo mÃtodo Bayesiano Local e na anÃlise Scan Espacial. O estudo mostra que a hansenÃase à hiperendÃmica na Ãrea de estudo, sem a perspectiva de exaurir estes casos nos prÃximos anos. AlÃm de diagnÃstico tardio em um nÃmero de casos considerÃvel, houve lacunas na descentralizaÃÃo do atendimento, evidenciado pelo fluxo das pessoas afetadas. A construÃÃo de mapas utilizando outros indicadores, alÃm do coeficiente de detecÃÃo geral, e a sobreposiÃÃo desses mapas pÃde identificar Ãreas desconhecidas em relaÃÃo ao risco de transmissÃo e de detecÃÃo de casos com incapacidades avanÃadas. Essa abordagem poderà ser aplicada em outras Ãreas de risco para assim identificar agregados mais especÃficos de risco elevado para a hansenÃase. / In recent years, the National Leprosy Control has focused its actions on defined geographic areas with high leprosy detection rates. This study aimed to characterize epidemiological, spatial and temporal patterns in a high risk leprosy cluster in municipalities in the states of MaranhÃo, ParÃ, Piauà and Tocantins. Different methods of spatial analysis were applied (Descriptive, Local Bayesian Approach, Spatial Scan Statistics), and the spatial dependence of various epidemiological and operational indicators was quantified. In an additional study, I identified the flow of leprosy-affected individuals, and the reasons for migration after diagnosis. In the period 2001â2009, 82,463 new cases were detected in the endemic cluster (mean detection rate: 95.9/100mil inhabitants per year). In the rest of Brazil, the mean rate was 21.0 (RR=4.56, 95% CI: 4.45 - 4.66; p<0.0001). There was a directed flow of patients who were reported by a municipality other than their residence. AraguaÃna, Imperatriz, Marabà and Floriano notified a considerable number of cases from the municipalities in the proximity. SÃo LuÃs, Teresina and BelÃm received also cases from other states. GoiÃnia and BrasÃlia are distant from the cluster, but reported cases from the cluster. After first diagnosis, in 53.5% of cases migration was related to lifestyle changes. Spatial Scan analysis identified 23 clusters of high detection rates, most of them located in Parà and MaranhÃo. These clusters included only 32% of the population but 55.4% of new cases, and 101 (27.1%) municipalities. There were also 14 significant clusters for high detection rates in children, and 11 clusters of new cases with grade 2 disabilities/100.000 population. The most significant cluster, in the centre of MaranhÃo, had a RR of 2.24 and an annual detection of grade 2 cases of 10.4/100.000 population. The local auto-correlation method showed overlapping with high-risk areas identified by Local Bayesian and Spatial Scan Statistics. The study shows that leprosy is hyperendemic in the study area, without an expected trend of reduced detection rates in the coming years. In addition to late diagnosis in a considerable number of cases, there were shortcomings in the decentralization of the health system, evidenced by the flow of affected people. The use of maps based on other indicators than detection rates and the overlap of these maps highlighted previously unknown risk areas for transmission and for cases with advanced disabilities. This approach can beapplied in other endemic areas to identify clusters of high risk for leprosy.

O primeiro surto de melioidose no Brasil ocorreu quando quatro adolescentes apresentaram forma grave da doenÃa, com pneumonia e sepse, numa pequena comunidade rural do Nordeste do Brasil, em fevereiro de 2003. Burkolderia pseudomallei foi identificada, em cultura de sangue em um caso, inicialmente por mÃtodos convencionais e confirmado por amplificaÃÃo de Ãcido nuclÃico (PCR). O diagnÃstico foi presumÃvel nos outros trÃs casos. A investigaÃÃo epidemiolÃgica preliminar identificou os possÃveis fatores contribuintes: inÃcio dos sintomas durante perÃodo chuvoso,exposiÃÃo dos casos a solo e Ãgua em atividades de lazer, presenÃa de barragem de um rio prÃximo ao domicÃlio, Ãrea ao redor do domicÃlio exposta a grande chuva dois dias antes dos sintomas e casa com piso de terra. O fato das crianÃas adoecerem no mesmo dia aponta para uma possÃvel exposiÃÃo comum e simultÃnea. A barragem foi identificada como o local mais provÃvel da contaminaÃÃo e o mecanismo de transmissÃo possivelmente pode ter ocorrido por aspiraÃÃo, inalaÃÃo ou ingestÃo de Ãgua da barragem. O recente surto levanta o questionamento sobre a existÃncia da doenÃa no Brasil e mostra a necessidade de estudo ambiental detalhado para compreender sua ocorrÃncia. / The first melioidosis outbreak in Brazil happened when four adolescents presented a severe case of the disease, with pneumonia and sepsis, in a small rural community in the Northeast of Brazil, in February 2003. Burkolderia pseudomallei were identified through blood culture in one case, firstly using conventional methods and then confirmed by PCR. The diagnosis was presumptive in the other three cases. The preliminary epidemiological investigation identified the possible contributing factors: onset of the symptoms during the rainy season, exposure of the cases to the soil and water in leisure activities, presence of a river dam close to the residence, the area around the house had been exposed to heavy rain two days before the symptoms, and the house had dirt floor. The fact that the children got sick on the same day, points to a possible common and simultaneous exposure. The dam was identified as the most probable place of contamination, and the transmission mechanism might have happened through aspiration, inhalation or ingestion of water from the dam. The recent outbreak rises the important questioning about the existence of the disease in Brazil, and shows the need of a detailed environmental study to understand its occurrence.

A model was formulated to estimate tree component weight by geometrically describing the tree with basic tree parameters such as diameter, height, crown width, and crown length and the shape equations that relate them. The stem is divided into three sections with shape equations to describe the wood and bark in each section. The crown is divided into three sections with three equations. The main branch stems are described in three sections by six equations as in the stem. The shapes and their defining parameters provide a volume estimate for the tree components. The density of the wood and bark in each section of the stem and branches is estimated as a random variable. The density of the crown is defined by estimates of interwhorl distances and numbers of branches per whorl, both of which are random variables. The length of the branches also Influences the density of the crown because the weight of the needles and branchlets is a function of branch length. The density and volume of the components combine to give estimates of the weight of the components. In addition to this indirect calculation of tree component weight, the model calculates-the weight of individual tree components with equations having specific tree parameters as independent variables. The estimates of weight are used to calculate the quantity of slash per tree and the center of mass of each major tree component. The weights of the stump and the unmerchantable top are also calculated in conjunction with the slash calculations. The weights and centers of mass are produced in tabular form. The accuracy of the model is limited by the accuracy of the input data. The model was verified for Douglas-fir, western hemlock, and western redcedar. The verification procedure included manual calculations and comparison with other estimates of weight. The model in its present form can aid in understanding the quantitative effects on the tree of variation in the parameters which describe the tree. Because the weight and volume of the tree components influence their combustibility, the model can aid in describing the tree component of the forest fuel complex. New data and further analyses would be needed to determine the full potential and practical utility of the model described herein. / Forestry, Faculty of / Graduate

A thesis submitted to Faculty of Health Sciences, University of the Witwatersrand, in fulfillment of the requirements for the degree of Doctor of Philosophy Johannesburg, March 2014 / The ability to induce a broadly neutralizing antibody (bNAb) response following vaccination is regarded as a crucial aspect in developing an effective vaccine targeting the human immunodeficiency virus type 1 (HIV-1). The bNAbs target the HIV-1 envelope glycoprotein (Env) which is exposed on the surface of the virion, thereby preventing cell entry. Previous work in our laboratory focused on the generation of a 2dCD4S60C molecule (a variant of the CD4 primary Env receptor) with higher affinity for HIV-1 Env through targeted disulphide exchange. This study reports on the design and construction of an HIV-1 subtype C founder virus consensus Env immunogen derived from newly transmitted/founder virus sequences, and the ability of the purified recombinant Env proteins (2dCD4S60C-liganded and unliganded) to induce a broadly neutralizing antibody response in small animals. A total of 1894 founder sequences from 80 HIV-1 subtype C infected patients were available and downloaded from the databases. A consensus sequence was generated for each of the patients, and this alignment was subsequently used to generate a founder virus consensus env sequence. The env sequence was used to create codon-optimized constructs encoding monomeric (gp120FVCm), dimeric (gp120FVCGCN4d) and trimeric (gp140FVCGCN4t(+) and gp140FVCGCN4t(-) founder virus conformations cloned into the pcDNA3.1(-) mammalian expression vector. All four Env constructs were successfully expressed in HEK293T mammalian cell culture. The 2dCD4S60C was expressed in E. coli BL21 (DE3) and purified by nickel affinity chromatography. Large scale expression and purification of the gp120, gp120GCN4 and gp140GCN4 +/- in the unliganded or 2dCD4S60C liganded state were purified by lectin affinity chromatography, followed by conformation and complex purification using size exclusion chromatography. Immunogens/immune complexes were evaluated by ELISA, SDS-PAGE, native PAGE and surface plasmon resonance, and confirmed they were functional and conformationally intact. Immunogenicity of each conformation alone or complexed to 2dCD4S60C was evaluated in rabbits. Breadth and potency of the rabbit sera was tested against 12 pseudoviruses (Tiers 1-3), derived from HIV-1 subtype B and C Env, using the PhenoSense Neutralizing antibody assay (Monogram Bioscience, Inc.). Minimal neutralizing breadth was obtained from animals immunized exclusively with Env conformations. However, animals that received the Env/2dCD4S60C complex showed extensive neutralizing capacity against all 12 viruses tested, including the tier 2 and 3 virus strains. End-point ELISA titer results revealed that the rabbits that were immunized with Env/2dCD4S60C produced both Env and 2dCD4S60C specific titers, but those directed towards 2dCD4 were on average 10x lower than the 2dCD4S60C control group. This implies a proportion of the NAb activity is directed towards conserved epitopes exposed on the Env/2dCD4S60C immunogens. Overall, these results show that the use of founder Env/2dCD4S60C complexes as vaccine immunogens dramatically improves the antibody neutralization breadth and magnitude as compared to founder Env or 2dCD4S60C alone. This level of broad neutralization has not been previously reported in the literature, and these results provide encouraging data to inform us of the best envelope vaccine immunogen to include in a preventative vaccine.

Dietary starch that escapes digestion in the small intestine may be quantitatively more important than dietary fibre as substrate for fermentation. The products of fermentation have important implications in the pathogenesis of colorectal cancer and other diseases of the large bowel which are uncommon in Africans, but have a high prevalence in Western populations. Maize porridge is a staple of most Blacks in South Africa. Stale maize porridge (high resistant starch - HRS) seems to induce greater fermentation in the large bowel than fresh maize porridge (low resistant starch - LRS). In the present study, healthy colostomy subjects fed stale maize porridge had significantly more production of SCFA (short chain fatty acids) (mean SCFA - HRS = 182,6; mean SCFA - LRS = 116,1; p<0,05) in their colostomy effluent together with a significant drop in stool pH (mean pH - HRS = 5,91; mean pH - LRS = 6,70; p<0.G01). The SCFA butyrate tmean - HRS = 35,1; mean - LRS - LRS = 17,6; p<0,05) and acetate (mean - HRS = 93,9; mean - LRS = 65,8; p <0,05) were significantly elevated on the stale maize porridge diet when compared with consumption of fresh maize porridge. SCFA, propionate (mean - HRS = 43,1; mean - LRS = 24,8; p=G,Q5), also increased with stale maize porridge, but was not statistically significant. A high resistant starch diet and its resultant increase in fermentation products may be partly responsible in protecting the Black population against colorectal cancers and other large bowel diseases.

A research report submitted to the Faculty of Health Sciences (School of Public Health), University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master in Public Health in the field of Social and Behaviour Change Communication 4 June 2019, Johannesburg / Introduction HIV Testing Services (HTS) represents a critical entry point for reducing HIV risk through personalised counselling and testing (Colpin, 2006, Denison et al., 2008; Fonner, 2014). Despite the significant uptake of HTS since 2010, personal risk perception among South Africans remains low, with individuals continuing to engage in risky sexual behaviour (Statistics South Africa, 2017). This raises concerns about the quality and effectiveness of HTS in reducing HIV risk among HTS clients. In seeking to understand how best to strengthen HTS, lay counsellors who work at the forefront of HTS provision are primary targets for inquiry. This study sought to explore the experiences and perceptions of community-based HTS lay counsellors of providing HTS, the strategies they use to reduce HIV risk among diverse clients, and their perceptions of HTS training and supervision. Methods Qualitative semi-structured interviews were conducted with 12 community-based HTS counsellors at three government-accredited HTS sites in Gauteng and North West provinces. Ethical clearance was obtained in April 2015 and the interviews were conducted from July- October 2015. Interviews were audio-recorded, professionally transcribed, and coded using MaxQDA. Inductive and deductive thematic analysis was used to meet the study objectives. Results The HTS lay counsellors came from diverse personal and educational backgrounds. Their HTS training was not standardised, differing in scope, depth, and duration. Their sector influenced their scope of practice, remuneration and relationship with the Department of Health. HTS Counsellors tended to follow a client-centred approach to HIV counselling; balancing general HIV education with more tailored prevention counselling. Gender norms appeared to influence risk-reduction counselling, in which counsellors advised men to use condoms and women to be faithful to their partners. Counsellors resisted the notion of differential risk among HTS clients, and offered generic, simplified prevention messages tailored to clients‘ age and gender. Counsellors seldom explored known risk factors for HIV infection, such as alcohol and drug abuse, anal sex, and gender-based violence with clients. They prioritised post-test counselling for HIV-positive clients and tended to neglect post-test counselling for HIV-negative clients. . Counsellors recommended regular in-service training, enhanced supervision and debriefing, and formal recognition of the field through establishing standardised guidelines, career paths and a professional body. Discussion This study confirms previous research on the sub-optimal quality of risk-reduction counselling, which varies between sites and counsellors. Although HTS counsellors follow the nationally prescribed, client-centred approach, there is limited evidence that this approach effectively reduces HIV risk (Peltzer et al., 2013). In contrast, theory-based approaches, such as Motivational Behavioural Interviewing, which has effectively reduced unprotected sex, alcohol use before sex, number of sexual partners, and transactional sex among high risk groups globally and in South Africa (Petersen et al., 2014, Simbayi et al., 2004).were largely absent in HTS programmes covered in this study. The HTS lay counsellors in this study are among those who have contributed significantly to the rapid scale up of HTS in South Africa. However, they identified structural challenges detrimental to their work performance and motivation. HTS counsellors are not formally recognised or included within national human resources for health plans, and their job profiles and remuneration are not standardised. The inconsistent management and unfair treatment described by counsellors in this study has been reported across the country (Medecins Sans Frontieres, 2015). Conclusions The major recommendations that emerged from this study include the need for the government to create a supportive legal and policy framework to guide the integration of HTS counsellors into the formal health care system. This could happen by establishing a professional body for HTS counsellors and updating the minimum standards for HTS. Quality could be improved by training counsellors on use of individual and social theories of behaviour change (Petersen et al., 2014) and standardising HTS training curricula at national levels. Strengthening HTS vsupervision to ensure quality HTS counselling and testing nationally is also needed. Overall, this study confirmed that further research is needed to improve the quality of risk reduction interventions in HTS and develop a coherent framework for the integration of lay counsellors into the South African health and social service sectors. / E.K. 2019

No description available.

there is a growing body of research on men who have sex with men (MSM) and risk factors for HIV in South Africa. However, in order to develop more appropriate and relevant interventions to reduce the transmission of HIV amongst MSM and MSMW, there was a need to deepen our understanding of sexual risk behaviour and protective practices. The aim of the study was to explore the sexual risk and protective behaviour of men who have sex with men and women in Soweto, South Africa.