Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-10-04T12:34:05Z No. of bitstreams: 1 izabelladeoliveirapinheiro.pdf: 2789735 bytes, checksum: 88fd51d57fe8e1982bbacbad4e1341dc (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-10-04T12:39:56Z (GMT) No. of bitstreams: 1 izabelladeoliveirapinheiro.pdf: 2789735 bytes, checksum: 88fd51d57fe8e1982bbacbad4e1341dc (MD5) / Made available in DSpace on 2016-10-04T12:39:56Z (GMT). No. of bitstreams: 1 izabelladeoliveirapinheiro.pdf: 2789735 bytes, checksum: 88fd51d57fe8e1982bbacbad4e1341dc (MD5) Previous issue date: 2010-07-13 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Doenças tropicais negligenciadas (DTNs), assim classificadas pela Organização Mundial de Saúde, constituem um grupo de infecções praticamente eliminadas no mundo desenvolvido, mas que persistem em áreas pobres de países de baixa renda. Dentre elas estão a ascaridíase, a tricuríase e a ancilostomíase, cujos agentes etiológicos têm parte de seu ciclo evolutivo passando pelo solo, e são, por isso, denominadas de geohelmintoses. Recentemente, a giardíase também foi incluída como DTN, uma vez que sua forma de transmissão pode ser associada com falta de saneamento. Este estudo transversal de base populacional visou à investigação da ocorrência dessas parasitoses em três municípios do sudeste de Minas Gerais. Para tanto, 2367 indivíduos foram selecionados aleatoriamente. Os dados foram obtidos por meio de um questionário estruturado acerca das condições socioeconômicas, ambientais e culturais da população amostral e do exame de uma única amostra fecal de cada participante, pelo método de sedimentação espontânea (HPJ). Para cada amostra fecal foram examinadas cinco lâminas, e concluiu-se que o exame de três lâminas por amostra expressou a melhor relação custo-benefício para o SUS. A análise dos resultados mostrou que 6,1% (n=145) da população amostral estava infectada com uma ou duas DTNs. Dentre os indivíduos infectados, as prevalências observadas para ancilostomídeos, G. lamblia, T. trichiura e A. lumbricoides foram 47,3%, 27,3%, 16,0% e 9,3%, respectivamente. Na análise bivariada dos dados (p<0,05; IC 95%), o teste do Qui-quadrado de Pearson foi usado para avaliar a força das possíveis associações entre as variáveis independentes e o desfecho. Na análise de regressão logística, quatro variáveis permaneceram estatisticamente significantes, sugerindo serem os possíveis fatores de risco para as DTNs nos municípios: o destino inadequado do esgoto (p<0,001), o hábito de beber água não potável (p<0,001), a falta de instalação sanitária adequada (p=0,015) e pertencer ao sexo masculino (p<0,001). Os resultados encontrados neste estudo nos permitem concluir que DTNs estão presentes mesmo em regiões mais desenvolvidas do Brasil. O número de pessoas parasitadas confirma a área como de baixa endemicidade para geohelmintoses e giardíase em relação a outras regiões do Estado, e justifica estudos que avancem no conhecimento do perfil epidemiológico da região e subsidiem o desenvolvimento de políticas públicas locais. / Neglected tropical diseases (NTDs), so classified by the World Health Organization, are a group of infections that have been eliminated in the developed world, but still persist in poor areas of low-income countries. Among them, ascariasis, trichuriasis, and hookworm infection are soil-transmitted helminthiasis. Recently, and despite its worldwide distribution, giardiasis was also included in the WHO list, due to its way of transmission, which can be associated with lack of sanitation. This population-based cross-sectional survey aimed at investigating the occurrence of such infections in three municipalities of southeastern Minas Gerais state. A total of 2,367 individuals randomly chosen provided one single fecal sample. The baseline data consisted of a questionnaire and parasitological coproscopy using the HPJ method. Five slides were examined from each fecal sample, allowing us to conclude that, regarding this method, the examination of three slides per sample presented a satisfactory sensitivity and the best cost-effectiveness for the SUS. The results showed that 6.1% (n=145) of the population sample was infected with either one or two NTDs, of which the prevalences observed for hookworms, G. lamblia, T. trichiura, and A. lumbricoides were 47.3%, 27.3%, 16.0% e 9.3%, respectively. In the bivariate analysis (p<0.05; CI 95%), Pearson Qui-square tests were used to assess the strength of the associations. Multivariate analysis was run with all significant variables. Four variables remained significant in the logistic regression, as the possible risk factors for the installation and spread of the infections in the municipalities: inadequate sewage discharge (p<0.001), the habit of drinking unsafe water (p<0.001), lack of adequate sanitary infrastructure in the household (p=0.015), and masculine sex of the individual (p<0.001). Our findings allow us to conclude that NTDs occur even in more developed areas of Brazil. Our numbers confirm the study area as low endemic for giardiasis and soil-transmitted helminthiasis, and justify surveys in order to get more information on the epidemiological profile of the Zona da Mata Mineira region, aiming at giving support to the development of local health policies.

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.