Introduction Schistosomiasis is one of the most important and widespread diseases of rural poverty. Worldwide, approximately 779 million people are at risk of infection, with 207 million already infected. Infections with Ascaris lumbricoides, hookworms and Trichuris trichiura, collectively known as the soil-transmitted helminths (STHs), are also highly endemic throughout the tropics, particularly in resource-poor settings. An estimated 1 billion people worldwide are estimated to be infected with STHs. Schistosomes and STHs often co-exist in the same epidemiological settings and, given the high prevalence of concurrent multiple species infections (multiparasitism), a combined approach to prevention and control could lead to significant improvements, including reducing costs associated with single-species control programmes. In China, rigorous national schistosomiasis control efforts over the past 60 years have decreased the prevalence by over 90%; however, since 2000 the number of infected individuals has been rising, possibly indicative of a re-emergence. Fishermen, migrant communities and poor households in rural areas may be most at risk of single and multiple-species parasitic infections and the associated morbidity. Objectives This Ph.D. thesis is structured according to four main goals and a number of specific objectives: Firstly, to update estimates of S. japonicum prevalence, intensity and associated morbidity levels in Hunan province, China, according to the third national PES carried out in 2004; Secondly, to investigate existing barriers in access to preventive, diagnostic and treatment services for advanced schistosomiasis; Thirdly, to compare and evaluate direct and proxy methods of measuring household socio-economic position, according to data on income, savings and asset-based estimations of wealth; and Finally, to explore and identify behavioural, demographic, economic, environmental and social risk factors associated with the distribution of S. japonicum, STHs and multiple species infections, in two villages of the Dongting Lake region, Hunan province, China. Methods Firstly, we used data from the third national schistosomiasis periodic epidemiological survey (PES) of 2004. In Hunan province, the PES was carried out in 47 villages of the endemic Dongting lake area. A total of 47144 human serological, 7205 stool, and 3893 clinical examinations were performed. For the reservoir hosts, stools from 874 buffaloes and other domestic animals were examined for schistosomiasis by the miracidial hatching test. Secondly, we conducted an in-depth study involving interviews with 66 schistosomiasis control staff and 79 advanced schistosomiasis patient, and six focus group discussions (FGDs), in the Dongting lake region, between August 2002 and February 2003. Using the Health-Access Livelihood framework we examined availability, accessibility, affordability, adequacy and acceptability of schistosomiasis control in the Dongting lake area. Lastly, we carried out two village-wide parasitological, clinical and questionnaire-based investigations between October and December 2006. Parasitological examinations for the prevalence of S. japonicum and the STHs were performed by the Kato-Katz thick smear method, with repeated sampling of each individual. We took fingerprick blood samples to assess haemoglobin levels, using a B-haemoglobin HemoCue photometer. The household-based questionnaire focused on direct and proxy measurements of household wealth, while the individual-based questionnaire focused on demographic and behavioural factors, treatment history and self-perceived symptoms. Results Human sero-prevalence was 11.9% (range: 1.3-34.9% at village level), and the rate of egg-positive stools was 1.9% (0-10.9%) for the same population. The prevalence of infection among buffaloes was 9.5% (0-66.7%). Extrapolating to the entire population of the Dongting Lake region, an estimated 73225 people and 13973 buffaloes were infected. Most frequently reported symptoms were abdominal pain (6.2%) and bloody stools (2.7%). Accessibility and affordability were major barriers in access to schistosomiasis control. Many of staff interviewed indicated that a majority of patients who develop advanced schistosomiasis resided in mildly-endemic or non-endemic settings. None of the patients interviewed had any form of health insurance, and most of their health expenses were out-of-pocket payments. Exploratory factor analysis generated internally robust proxy wealth indices, however these were not complementary to direct measures of household wealth, as indicated by low correlation co-efficients. We found wide disparities in household ownership of durable assets, utility and sanitation, within both settings. Pooled data from the rural and peri-urban settings highlighted structural differences in socioeconomic position (SEP), more likely a result of localised urbanization and modernization. We found higher infection prevalences in rural settings, than in peri-urban settings, for schistosomiasis (6.3% and 6.7% respectively), ascariasis (8.3% and 2.2%, respectively) and trichuriasis (5.1% and 0.5%, respectively), but lower for hookworms (0.1% and 1.5% respectively). Multiple species infections (2.6% and 0.2%, respectively) were less prevalent than single species infections (14.5% and 10.4%). There were significant disparities in the prevalence of parasitic infections between poorest and least poor quintiles of the cohort population. Anaemia and other symptoms, especially headache, stomach ache and swollen stomach, were common in both rural and peri-urban village settings. Conclusion The studies conducted within the framework of this Ph.D. thesis document the current situation pertaining to schistosomiasis and the STHs in Hunan province, China. Our findings highlight the need for increased surveillance, monitoring and health education, with relation to schistosomiasis and STHs, in non-endemic or post-transmission control settings. Based upon these results, we call for improved diagnostic tools, particularly in the case of low intensity infections and for hookworm, and propose an extension of the use of available infrastructure, human resources, knowledge and technology by integrating prevention and control of schistosomiasis with that of other intestinal helminths, particularly STHs. In the future, our studies may form a base from which to further examine local needs and priorities for parasitic disease control in the area.

Made available in DSpace on 2015-07-22T20:49:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-05-25 / Introdução: a prevalência de doenças alérgicas tem aumentado no mundo, particularmente nas populações urbanas de países em desenvolvimento. Objetivos: determinar a prevalência de asma e doenças alérgicas, identificar fatores de risco a elas associados, avaliar a relação entre asma e helmintíase, assim como a relação entre a cicatriz vacinal do BCG e sensibilização atópica em escolares ribeirinhos de Ilhas da Amazônia. Métodos: estudo transversal em 400 escolares (5 a 8 anos) cujos pais responderam os questionários escritos (padrão e complementar) do International Study of Asma and Allergies in Childhood, entre 2007 e 2009. As crianças também foram avaliadas quanto a: medição da cicatriz vacinal do BCG, coletas de fezes (parasitológico) e sangue para dosagem de IgE total e específica séricas. Foram utilizados testes não paramétricos e os fatores de risco foram identificados por regressão logística (stepwise forward) tendo-se como nível de significância 5%. Resultados: prevalência de asma atual e rinoconjuntivite atual foram significantemente maiores entre as crianças vivendo na ilha de Outeiro do que nas da Ilha do Combú (30,5% X 16,5%; 18% x 6%, respectivamente). Nas duas ilhas, ter relato de asma ou rinite nos pais, ter antecedentes pessoais de rinite e tosse noturna no último ano estiveram associados à maior expressão de asma. A regressão logística identificou os riscos de ter asma: na ilha do Combú foram antecedente familiar de asma, ter gato na atualidade e tosse noturna no último ano. Na do Outeiro foram: antecedente familiar de asma, antecedente pessoal de eczema, ter dois ou mais irmãos mais velhos e tosse noturna no último ano. Conjuntamente para as duas ilhas os riscos foram: tosse noturna no último ano e antecedente familiar de asma. Não houve diferença significante entre parasitados e não por helmintos em relação à expressão da asma, exceto ter diagnóstico médico de asma, mais frequente entre as crianças parasitadas. Níveis séricos de IgE total e de IgE específica a A.lumbricoides foram mais elevados nas crianças parasitadas. Correlação entre os níveis séricos de IgE sérica total e as específicas aos alérgenos mostrou significância para Periplaneta americana e A.lumbricoides entre os parasitados e entre os não parasitados foi com B.germanica e B.tropicalis. Correlação entre o diâmetro médio da pápula induzida pelos aerolérgenos e o nível de IgE sérica específica para D.pteronyssinus e B.tropicalis foi significante entre os não parasitados. Diâmetro médio da cicatriz vacinal do BCG das crianças com asma não diferiu das sem. Não houve correlação significante entre os níveis séricos de IgE total e específica e o diâmetro médio da cicatriz vacinal do BCG. Conclusões: houve variação na prevalência de asma e rinite entre as ilhas, sendo mais elevada na do Outeiro, que possui características de zona urbana. Os fatores de risco de ter asma foram diferentes para as duas ilhas refletindo as características individuais de cada ilha e conjuntamente foi o antecedente familiar de asma, enfatizando a participação da genética como importante fator de risco. Os helmintos não foram associados à expressão da asma nem da sensibilização alérgica. É importante criar medidas preventivas mais apropriadas contra o desenvolvimento de asma para cada uma das ilhas. Mais estudos são necessários para clarificar o papel dos helmintos sobre a asma e doenças alérgicas. / Background: epidemiological studies have focused on possible association between helminth infection and the development of asthma and/or allergies. Objectives: to evaluate the association between helminth infection and asthma and its relation to serum levels of total and specific IgE for A. lumbricoides and aeroallergens, besides evaluating possible relation between BCG scar and allergic sensitization. Methods: cross sectional study in 400 schoolchildren from two Amazon Islands. A standardized written questionnaire (asthma module) from International Study of Asthma, Allergies in Childhood protocol was administered and asthmatic children were those with current wheezing. The following procedures were done: skin prick test (positive test with papule mean diameter > 3mm); blood samples for assessment of serum levels of total and specific IgE for A. lumbricoides and aeroallergens (positive those with levels > 0.36 kU/L); feces samples for helminths examination (positive = infected with at least one helminth); mean diameter of BCG vaccine scar measurement. Analyses were assessed for both islands together and non-parametric tests were applied obtaining 5% of significance level. Results: there was no significant difference between infected and non-infected children with helminths related to asthma expression, save for having physician-diagnosed asthma that was more frequent in helminths infected children. Serum levels of total and specific IgE for A. lumbricoides were higher in infected children. Significant correlations between serum levels of total and specific IgE for aeroallergens to Periplaneta americana and Ascaris lumbricoides among those infected and among those non-infected was for B. germanica e B. tropicalis. Significant correlation between papule mean diameter and serum level of specific IgE for D. pteronyssinus e B. tropicalis among those not infected. Mean diameter of BCG vaccine wasn´t different among children with asthma and those without, as well as there was no correlation between serum levels of total and specific IgE. Conclusions: parasite infections are not associated with either asthma expression or to allergic sensitization, but positive association was verified between physician-diagnosed asthma and helminth infection. More studies are necessary to clarify helminth infection role on asthma and allergic diseases. / TEDE / BV UNIFESP: Teses e dissertações

Made available in DSpace on 2015-03-26T13:46:53Z (GMT). No. of bitstreams: 1 texto completo.pdf: 289107 bytes, checksum: 35ee72e2a4506163a5f402f0961d85fc (MD5) Previous issue date: 2004-05-19 / The viability of a formulation of the fungus Monacrosporium thaumasium (Drechsler, 1937) was evaluated for the biological control of bovine gastrointestinal nematode parasites. Two groups of seven female calves each, holstein x zebu crossbred, four to six months of age, were placed in Cynodon dactylon pastures. In group A, each animal received 20g of pellets of M. thaumasium orally twice a week during a four-month period that began with the onset of the rainy season (October, 2001). In group B (control), the calves did not receive any fungal treatment. The counts of eggs per gram of faeces (EPG) for anima1s of the group B were significantly greater (P< 0.05) than those for animaIs of the group A and the difference of the EPG between the animals of group A and B at the end of the study period was 88,8%. The nematodes of the Cooperia genus were the most prevalent in the both pastures. It is concluded that use of this dose and periodicity of application of M. thaumasium pellets were efficient in the control of bovine gastrointestinal nematode parasites. / A viabilidade de uma formulação do fungo Monacrosporium thaumasium (Drechsler, 1937) foi avaliada no controle biológico de nematóides parasitos gastrintestinais de bovinos. Dois grupos de sete bezerras cada, mestiças holandês x zebu, de quatro a seis meses de idade, foram colocados em pastagens de Cynodon dactylon. No grupo A, cada animal recebeu 20 g de péletes (formulação granulada) de M. thaumasium via oral, duas vezes por semana, durante quatro meses, com início na estação chuvosa (outubro de 2001). No grupo B (controle), os bezerros não receberam nenhum tratamento fúngico. As contagens de ovos por grama de fezes (OPG) dos animais e das larvas infectantes encontradas na pastagem do grupo B foram significativamente maiores (P< 0,05) do que as dos animais do grupo A, e a diferença entre o OPG dos animais do grupo A e o do grupo B, no final do experimento, foi de 88,8%. Os nematóides do gênero Cooperia foram os mais prevalentes em ambas as pastagens. Concluiu-se que a aplicação de péletes de M. thaumasium na dosagem e periodicidade de aplicação usadas foi eficiente no controle de nematóides parasitos gastrintestinais de bovinos.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Schistosomiasis and geo-helminthiasis are parasitic diseases considered as a serious public health problem, both related to poverty, lack of adequate sanitation and hygiene. The municipality of Malhador-SE join the campaign against geo-helminths and S. mansoni since 2013 and is engaged in the Program of Control of Schistosomiasis aiming the elimination of schistosomiasis and the reduction of the parasitic burden of geo-helminths. The purpose of this study was to compare the prevalences of S. mansoni and geo-helminths and socio-environmental conditions in schoolchildren in the municipality of Malhador / SE. An epidemiological, descriptive and cross - sectional study was carried out. The sampling took place in February 2016. The study involved schoolchildren between 5 and 14 years in two municipal schools located in an urban school (Pacheco School) and another in the rural area (Barrocão School). The prevalence of children with S. mansoni and / or geo-helminths was determined using the Kato-Katz method, and compared to the socio-environmental conditions of the students. The positive cases found in the communities were georeferenced with the aid of a GPS receiver and to analyze and visualize the pattern of the distribution and density of the cases the kernel estimator was applied. Of the 337 fecal samples collected, 48.7% resulted in positive samples. The prevalence of infection was 17.6% for S. mansoni, 23.7% for A. lumbricoides, 4% for T. trichiura and 0.4% for E. vermicularis in the urban area (Pacheco School). On the other hand, in the rural area (Barrocão School) were 55.9% for S. mansoni and 28.8% for A. lumbricoides. The highest frequency of S. mansoni was found in the rural area and in male children, whereas the cases of geo-helminths had similar prevalence in both zones. In the rural area, the parasitic burden prevailed in mild (87.9%) and moderate (12.1%) and in urban areas, mild (65.3%), moderate (28.6%) and severe (6.1%). Regarding the environmental and sanitary conditions, the children in the rural area had more "contact with water" (90.5%), being associated with the occurrence of S. mansoni in the demographic areas (p = 0.0394). Likewise, the variables "sanitary installation, waste disposal, water supply and waste destination" also showed an association between the "occurrence of S. mansoni and geo-helminths" (p <0.001). Of the hygiene habits, 100% of rural schoolchildren consume untreated water (p <0.001). The analysis of the spatial distribution of the positive cases of S. mansoni and geo-helminths allowed us to visualize that in the urban area the specialization was revealed homogeneously, whereas in the rural zone it was heterogeneous and that through the Kernel estimator, the agglomeration of these cases is located in the west of Malhador in the urban and rural areas are located to the west and east of the municipality. The present study showed that Malhador is a municipality endemic to S. mansoni and that inadequate sanitary and hygiene conditions favored a high prevalence of parasitic diseases in the schoolchildren of the localities. / A esquistossomose e as geo-helmintíases são doenças parasitárias consideradas como um grave problema de saúde pública, ambas, relacionadas com a pobreza, a falta de saneamento adequado e de higiene. O município de Malhador-SE participa da campanha contra geo-helmintos e S mansoni desde 2013 e trabalha com o Programa de Controle da Esquistossomose com o objetivo de alcançar a meta de eliminação da esquistossomose e redução da carga parasitária de geo-helmintos. O objetivo desse estudo foi analisar, comparativamente, as prevalências de S. mansoni e geo-helmintos e condições sócio-ambientais em escolares do município de Malhador/SE. Foi realizado um estudo epidemiológico, descritivo e de corte transversal. A obtenção das amostras ocorreu no período de fevereiro a junho de 2016. O estudo envolveu escolares entre 5 e 14 anos em duas escolas municipais localizadas uma na zona urbana (Escola Pacheco) e outra na zona rural (Escola Barrocão). Foram identificadas as prevalências de crianças com S. mansoni e/ou geo-helmintos através do método Kato-Katz, e comparadas às condições sócio-ambientais dos escolares. Os casos positivos encontrados nas comunidades foram georreferenciados com o auxílio de um receptor GPS e para analisar e visualizar o padrão da distribuição e densidade dos casos foi aplicado o estimador de Kernel. Das 337 amostras de fezes coletadas, 48,7% resultou em positivas. As prevalências de infecção foram de 17,6% para S. mansoni, 23,7% para A. lumbricoides, 4% para T. trichiura e 0,4% para E. vermiculares na zona urbana (escola Pacheco), enquanto que, na área rural (escola Barrocão) foram de 55,9% para S. mansoni e 28,8% para A. lumbricoides. A maior frequência de S. mansoni foi encontrada na zona rural e em crianças do gênero masculino, enquanto que os casos de geo-helmintos tiveram prevalências semelhantes em ambas as zonas. Na zona rural prevaleceram as cargas parasitárias leve (87,9%) e moderada (12,1%) e na urbana, prevaleceram a leve (65,3%), moderada (28,6%) e grave (6,1%). Em relação às condições ambientais e sanitárias as crianças da zona rural tiveram maior “contato com água” (90,5%) estando associado com a ocorrência de S. mansoni nas áreas demográficas (p=0,0394). Da mesma forma, as variáveis “instalação sanitária, destino dos dejetos, abastecimento de água e destino do lixo” também mostraram associação entre a “ocorrência de S. mansoni e geo-helmintos” (p<0,001). Dos hábitos de higiene, 100% dos escolares da área rural consomem água não tratada (p<0,001). A análise da distribuição espacial dos casos positivos de S. mansoni e geo-helmintos permitiu visualizar que na área urbana a espacialização foi revelada de forma homogênea, enquanto que na zona rural apresentou-se heterogênea e que através do estimador de Kernel, a aglomeração desses casos está localizada a oeste de Malhador na zona urbana e na rural estão localizados a oeste e a leste do município. O atual estudo mostrou que Malhador é um município endêmico para S. mansoni e que as condições sanitárias e de higiene inadequadas favoreceram a elevada prevalência das parasitoses nos escolares das localidades.

MSc (Applied Mathematics) / Department of Mathematics and Applied Mathematics / In this study, we develop a multiscale model of soil transmitted helminths in humans with a special reference to hookworm infection. Firstly, we develop a single scale model that comprises of five between host scale populations namely; susceptible humans, infected humans, eggs in the physical environment, noninfective worms in the physical environment and infective worms in the physical environment. Secondly, we extend the single scale model to incorporate within-host scales namely; infective larvae within-host, immature worms in small intestine, mature worm population and within-host egg population which resulted to a multiscale model. The models are analysed both numerically and analytically. The models are epidemiologically and mathematically well posed. Numerical simulation results show that there is a bidirectional relationship between the between-host and within-host scales. This is in agreement with the sensitivity analysis results, we noted that the same parameters that reduce reproductive number R0 are the same parameters that reduce the infective worms endemic equilibrium point. From the comparative effectiveness of hookworm interventions analysis results, we notice that any intervention combination that include wearing shoes controls and reduces the spread of the infection. The modelling framework developed in this study is vigorous to be applicable to other soil transmitted helminths infections / NRF

Traditional medicine in South Africa is part of the culture of the people and has been in existence for a long-time. Although animal components form part of the ingredients used, plant material constitutes the major component. South Africa is endowed with vast resources of medicinal and aromatic plants which have been employed for treatment against various diseases for decades. A large number of South Africans still depend on traditional medicine for their healthcare needs due to its affordability, accessibility and cultural importance. Helminth infections are among the variety of diseases treated by traditional healers. These infections are regarded as neglected tropical diseases (NTDs) due to their high prevalence among the economically disadvantaged living in rural areas in different regions of the world. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

MPH / Department of Public Health

<p>Studies were performed on methodological issues on vitamin A intake, status and improvement in three Asian countries, to improve the dietary approach recommended by FAO/WHO to alleviate vitamin A deficiency in low-income countries.</p><p>The reliability of the practical 24-hour dietary recall method to assess individual intake of vitamin A during pregnancy was investigated in Central Java, Indonesia. The usual mean intake of vitamin A can be reliably measured, but data on attenuation of simple regression coefficients suggest that it is difficult to establish associations between vitamin A intake and some health outcome. The majority of women was below the recommended daily intake of vitamin A in all three trimesters and strategies to improve vitamin A intake in all women are thus needed.</p><p>The applicability of the simplified "Helen Keller International Food Frequency Method" to assess community risk of vitamin A deficiency in South Asia, even though it excludes breastmilk and animal milk, was tested in rural Bangladesh and rural India. Breast milk was found to be an important source of vitamin A even in the second and third years of life in rural areas of Bangladesh. Similarly, animal milk is likely to be an important source of vitamin A among preschoolers in certain areas of India. The method should be revalidated to make it a useful tool even in settings where breastmilk and animal milk are common in the diets of preschool children.</p><p>Whether it is possible to improve vitamin A status with dark green leafy vegetables in children free of <i>Ascaris lumbricoides</i> was investigated in northern Bangladesh. A substantial increase in serum β-carotene was seen after supplementary feeding of these vegetables for 6 weeks. The impact on serum retinol concentrations was less substantial.</p>

Studies were performed on methodological issues on vitamin A intake, status and improvement in three Asian countries, to improve the dietary approach recommended by FAO/WHO to alleviate vitamin A deficiency in low-income countries. The reliability of the practical 24-hour dietary recall method to assess individual intake of vitamin A during pregnancy was investigated in Central Java, Indonesia. The usual mean intake of vitamin A can be reliably measured, but data on attenuation of simple regression coefficients suggest that it is difficult to establish associations between vitamin A intake and some health outcome. The majority of women was below the recommended daily intake of vitamin A in all three trimesters and strategies to improve vitamin A intake in all women are thus needed. The applicability of the simplified "Helen Keller International Food Frequency Method" to assess community risk of vitamin A deficiency in South Asia, even though it excludes breastmilk and animal milk, was tested in rural Bangladesh and rural India. Breast milk was found to be an important source of vitamin A even in the second and third years of life in rural areas of Bangladesh. Similarly, animal milk is likely to be an important source of vitamin A among preschoolers in certain areas of India. The method should be revalidated to make it a useful tool even in settings where breastmilk and animal milk are common in the diets of preschool children. Whether it is possible to improve vitamin A status with dark green leafy vegetables in children free of Ascaris lumbricoides was investigated in northern Bangladesh. A substantial increase in serum β-carotene was seen after supplementary feeding of these vegetables for 6 weeks. The impact on serum retinol concentrations was less substantial.