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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Avaliação da qualidade virológica do efluente doméstico tratado e disponibilizado para reúso na cidade de São Paulo. / Evaluation of virological quality of treated wastewater available for urban reuse in Sao Paulo city.

Patricia Garrafa 25 May 2009 (has links)
O objetivo deste estudo foi avaliar a qualidade virológica da água de reúso produzida em uma das estações de tratamento de esgoto da cidade de São Paulo. Para tanto, foram coletadas concomitantemente 177 amostras de esgoto tratado (100L) e bruto (15L) e os vírus concentrados utilizando método Viradel-ultracentrifugação. Em seguida as amostras foram tratadas com Vertrel XF e os ácidos nucléicos extraídos para a detecção de adenovírus (HAdV), rotavírus (RV-A), norovírus e vírus da hepatite A (VHA). A detecção por PCR e/ou RT-PCR evidenciou RV-A (G1-G5), VHA e HAdV incluindo os da espécie F tanto no esgoto bruto quanto no tratado, no entanto norovírus não foram detectados em ambos os efluentes. A infectividade de RV-A e HAdV foi avaliada por cultivo celular e os rotavírus RV-A foram também quantificados por reação de imunoperoxidase direta. PCR em tempo real foi padronizada para quantificação de vírus não cultiváveis ou de difícil cultivo como os VHA. Com base nos resultados obtidos foi verificada a ocorrência e a distribuição anual de cada vírus nas águas de reúso. / The aim of the study was to evaluate the virological quality from one Sewage Treatment Plant in the state of São Paulo. From January/2005 to November/2006, 177 samples (15L) of raw sewage were collected at the entrance and another 177 (100L) at the end of treatment, twice a week. Viruses were concentrated by filtration through positively charged microporous filters, followed by ultracentrifugation. Virus concentrates were treated by using Vertrel-XF and the viral genomes extracted for detection of adenovirus (HAdV), rotavirus (RV-A), norovirus and hepatitis A virus (HAV). PCR and RT-PCR revealed RV-A (G1-G5), HAV and HAdV, including the enteric ones (species F) in sewage and treated wastewater samples. Norovirus was not detected in any samples. The infectivity of HAdV and RV-A was assayed by inoculating onto suitable cell line. Immunoperoxidase assay was used to calculate the rotavirus FFU/L in the samples. Real time-PCR was standardized for enumeration of non-cultivable virus. The occurrence and annual distribution of each virus in reuse water were analyzed.
202

Avaliações econômicas de programas de vacinação: as estimativas de custos em intervenções preventivas / Economic evaluations of vaccination programmes: cost estimates of preventive interventions

Valentim, Joice 14 October 2009 (has links)
Esta tese representa o aprofundamento do estudo das estimativas de custos, componente integrante e determinante das avaliações econômicas, enquanto parte do projeto de pesquisa Estudos de custo-efetividade da incorporação de novas vacinas à rotina do Programa Nacional de Imunizações: Rotavírus, Varicela, Pneumocócica conjugada, Meningocócica C conjugada e Hepatite A desenvolvido por solicitação do Programa Nacional de Imunização/PNI da Secretaria de Vigilância em Saúde/SVS do Ministério da Saúde, a partir de 2005. A tese teve como objetivo analisar as condições de uso, dificuldades e repercussões de diferentes métodos de estimativas de custos em estudos de custo-efetividade de vacinas de duas tecnologias específicas, vacinas contra rotavírus e varicela, assim como a relação entre as estimativas de custos e os resultados. As estimativas de custos estão condicionadas pelas características gerais da doença sob análise (aguda no caso de rotavírus e com seqüela no caso de varicela), assim como por questões metodológicas gerais (escolha teórico-conceitual, métodos e fontes de dados) e especificidades do caso brasileiro. Para esta tese, houve maior detalhamento das estimativas de custos diretos no cuidado da doença, com a inclusão de custos específicos do sistema de saúde suplementar para as duas doenças, inclusão de participação pública na dispensação de medicamentos no caso de rotavírus e inclusão de custos de medicamentos do sistema público de saúde no caso de varicela. Como resultado, houve aumento do custo total da doença estimado de 16% para rotavírus e 11% para varicela, assim como aumento de economia (custo total da doença evitado) de 18% e 16%, respectivamente, com a introdução de cada vacina. Apesar do maior detalhamento das estimativas de custos ter reduzido a razão de custo-efetividade incremental em 20% para rotavírus e 4% para varicela, o nível de custo-efetividade dos dois programas de vacinação não foi alterado. Os resultados das avaliações econômicas de vacinação contra rotavírus e varicela mostraram-se mais sensíveis às estimativas de custos do programa de vacinação, em especial o preço da vacina, apontando a relevância do custo da tecnologia sob análise para incorporação em comparação aos demais custos / This thesis represents a deeper study of the cost estimates, an integrant and determinative component of economic evaluations, as part of the project Costeffectiveness studies of the incorporation of new vaccines into the routine of the National Immunisation Program: Rotavirus, Varicella, Pneumococcal conjugate, Meningococcal C conjugate and Hepatitis A. The project has been developed on the request of the National Immunisation Program/PNI of the Secretary of Sanitary Surveillance/SVS of the Ministry of Health since 2005. The objective of the thesis was to analyse the conditions of use, difficulties and repercussions of different cost estimates methods in the cost-effectiveness studies of two specific technologies, vaccines against rotavirus and varicella, as well as the relationship between the cost estimates and the results. The cost estimates are conditioned by general characteristics of the disease under analysis (acute in the case of rotavirus and with long-term disability in the case of varicella), general methodological issues (theoretical choice, methods and sources of data) and specificities to the Brazilian case. This thesis brings a more detailed estimation of direct medical costs, with the inclusion of specific costs of the private health care system for the two diseases, inclusion of public participation for dispensing drugs in the case of rotavirus and inclusion of drugs costs in the public health care system in the case of varicella. As a result, there was an estimated disease total cost increase of 16% for rotavirus and 11% for varicella, as well as increase of savings (disease total cost avoided) of 18% and 16%, respectively, with the introduction of each vaccine. Although the more detailed cost estimates have reduced the incremental cost-effectiveness ratio by 20% for rotavirus and 4% for varicella, the cost-effectiveness level of the two vaccination programs was not altered. The results of the economic evaluations of vaccination against rotavirus and varicella were more sensitive to the vaccination program cost estimates, especially the vaccine price, pointing out the relevance of the cost of the technology under analysis for incorporation comparatively to the other costs
203

Laboratory Studies of Virus Survival During Aerobic and Anaerobic Digestion of Sewage Sludge

Scheuerman, Phillip R., Farrah, Samuel R., Bitton, Gabriel 01 March 1991 (has links)
The survival of three enteroviruses (polio 1, coxsackie B3 and echo 1) and a rotavirus (SA-11) was studied under laboratory conditions. The effects of temperature, dissolved oxygen, detention time, sludge source and virus type on virus inactivation were determined. Temperature was the single most important factor influencing the rate of virus inactivation. No significant differences were found for virus inactivation rates at dissolved oxygen levels between 0.9 and 5.8 mg/l. However, the inactivation rate of the viruses under aerobic conditions was found to be significantly greater than the inactivation rate under anaerobic conditions (−0.77log10/day vs −0.33 log10/day). Sludge source, detention time and virus type did not significantly influence the rate of virus inactivation.
204

Efecto antiviral del extracto de tegumento de Pattalus mollis (Pepino de Mar) sobre Rotavirus Humano Tipo A

Garcia Candela, Jose Luis Enrique January 2018 (has links)
Publicación a texto completo no autorizada por el autor / Determina el efecto antiviral de los extractos del tegumento de Pattalus mollis sobre Rotavirus Humano Tipo A (RVH). Se realiza una evaluación citotóxica de los tres tipos de extractos del tegumento, siendo el de pepsina (PPe) el único que presenta toxicidad nula a partir de dosis de 2500 μg/mL. Para determinar el efecto de acción antiviral ejercido por el PPe durante diferentes tiempos de infección de RVH, se aplica el PPe mediante pre tratamiento y post tratamiento antes de la inoculación, mostrando el primero una buena actividad con un porcentaje de inhibición mayor a 99,9%, una CE50 de 96,39 μg/mL y un índice de selectividad (IS) de 280,55; a diferencia del segundo que muestra una nula actividad antiviral. Por otro se evalúa el efecto de acción antiviral ejercido por el PPe en las etapa de fusión viral de RVH mediante la aplicación en conjunto del RVH con el PPe y como control antiviral se usa Ribavirina, mostrando el PPe una buena actividad antiviral mediante la aplicación conjunta, presentando un porcentaje de inhibición mayor de 99,9 %, una CE50 de 64,29 μg/mL y un IS de 420,63 a diferencia de la Ribavirina, la cual presenta un IS de 212,98. El estudio provee un mejor entendimiento sobre actividad antiviral de extractos de tegumento de Pattalus mollis sobre virus sin envoltura y específicamente nos permite concluir que el PPe de Pattalus mollis representa una alternativa prometedora como terapia antiviral contra RVH. / Tesis
205

Methods for Analysis of Disease Associated Genomic Sequence Variation

Lovmar, Lovisa January 2004 (has links)
<p>In Molecular Medicine a wide range of methods are applied to analyze the genome to find genetic predictors of human disease. Apart from predisposing disease, genetic variations may also serve as genetic markers in the search for factors underlying complex diseases. Additionally, they provide a means to distinguish between species, analyze evolutionary relationships and subdivide species into strains. </p><p>The development and improvement of laboratory techniques and computational methods was a spin-off effect of the Human Genome Project. The same techniques for analyzing genomic sequence variations may be used independent of organism or source of DNA or RNA. In this thesis, methods for high-throughput analysis of sequence variations were developed, evaluated and applied. </p><p>The performance of several genotyping assays were investigated prior to genotyping 4000 samples in a co-operative genetic epidemiological study. Sequence variations in the estrogen receptor alpha gene were found to be associated with an increased risk of breast and endometrial cancer in Swedish women.</p><p>Whole genome amplification (WGA) enables large scale genetic analysis of sparse amounts of biobanked DNA samples. The performance of two WGA methods was evaluated using four-color minisequencing on tag-arrays. Our in-house developed assay and “array of arrays” format allow up to 80 samples to be analyzed in parallel on a single microscope slide. Multiple displacement amplification by the Φ29 DNA polymerase gave essentially identical genotyping results as genomic DNA. To facilitate accurate method comparisons, a cluster quality assessment approach was established and applied to assess the performance of four commercially available DNA polymerases in the tag-array minisequencing assay. </p><p>A microarray method for genotyping human group A rotavirus (HRV) was developed and applied to an epidemiological survey of infectious HRV strains in Nicaragua. The method combines specific capture of amplified viral sequences on microarrays with genotype-specific DNA-polymerase mediated extension of capture oligonucleotides with fluorescent dNTPs.</p>
206

Methods for Analysis of Disease Associated Genomic Sequence Variation

Lovmar, Lovisa January 2004 (has links)
In Molecular Medicine a wide range of methods are applied to analyze the genome to find genetic predictors of human disease. Apart from predisposing disease, genetic variations may also serve as genetic markers in the search for factors underlying complex diseases. Additionally, they provide a means to distinguish between species, analyze evolutionary relationships and subdivide species into strains. The development and improvement of laboratory techniques and computational methods was a spin-off effect of the Human Genome Project. The same techniques for analyzing genomic sequence variations may be used independent of organism or source of DNA or RNA. In this thesis, methods for high-throughput analysis of sequence variations were developed, evaluated and applied. The performance of several genotyping assays were investigated prior to genotyping 4000 samples in a co-operative genetic epidemiological study. Sequence variations in the estrogen receptor alpha gene were found to be associated with an increased risk of breast and endometrial cancer in Swedish women. Whole genome amplification (WGA) enables large scale genetic analysis of sparse amounts of biobanked DNA samples. The performance of two WGA methods was evaluated using four-color minisequencing on tag-arrays. Our in-house developed assay and “array of arrays” format allow up to 80 samples to be analyzed in parallel on a single microscope slide. Multiple displacement amplification by the Φ29 DNA polymerase gave essentially identical genotyping results as genomic DNA. To facilitate accurate method comparisons, a cluster quality assessment approach was established and applied to assess the performance of four commercially available DNA polymerases in the tag-array minisequencing assay. A microarray method for genotyping human group A rotavirus (HRV) was developed and applied to an epidemiological survey of infectious HRV strains in Nicaragua. The method combines specific capture of amplified viral sequences on microarrays with genotype-specific DNA-polymerase mediated extension of capture oligonucleotides with fluorescent dNTPs.
207

Análise espacial das enteroinfecções em lactentes do município de Laranjeiras/SE após a introdução da vacina contra rotavírus / SPATIAL ANALYSIS OF INFANTS ENTEROINFECÇÕES IN THE COUNTY OF ORANGE / IF AFTER THE INTRODUCTION OF VACCINE ROTAVIRUS.

Santos, Claudimary Bispo dos 27 July 2012 (has links)
Acute diarrhea is the second leading cause of mortality among children under 5 years of age in developing countries. The pathogens most strongly associated with diarrhea is rotavirus followed by enteric pathogens such as bacteria, helminthes and protozoan. Adequate sanitation and water supply contribute to decrease acute diarrhea incidence of most etiologic agents, although vaccination remains the most important intervention to control rotavirus acute diarrhea. This study aimed to describe environmental exposures and spatial analysis associated with acute diarrhea and enteric pathogens among rotavirus vaccinated infants from Laranjeiras, Sergipe, Brazil. The children live in an area covered by Saúde da Família National Program and were 2 to 11 months old at enrollment. All reported children were followed for 12 months. Demographic, socioeconomic and environmental data were obtained from a questionnaire, and immunization data were obtained from children vaccination card. Children stool samples were collected each month in order to run laboratory analyses. The household spatial localization was obtained by using a Global Positioning System (GPS). Spatial analysis was performed using the TerraView computer program and Kernel intensity estimation. A total of 1,113 stool samples were collected, with 80 samples associated to diarrhea episodes. Diarrhea incidence rate was 0.50 ± 0.99 episodes/child/year. Overall, we observed 5.1% of Ascaris lumbricoides infection, 3.0% of Endolimax nana infection, 2.6% of rotavirus infection and 0.9% of Giardia lamblia infection. We observed rotavirus in 3.75% of stool samples associated with diarrhea but the majority (11.25%) of known diarrhea episodes was associated with helminthes and protozoan infections. There was no influence of environmental exposures on the number of episodes of diarrhea and enteroinfecções suggesting that environmental exposures are similar for the entire study sample. We observed some changes on spatial distribution of intestinal infections and diarrhea episodes along the four evaluated trimesters, especially on the urban center and adjacent areas. In conclusion, the studied infants live equally in poor urban drainage and poor sewerage areas which probably explain the significant rates of helminthes and protozoan infections appearing in early life. The low diarrhea incidence rate in this rotavirus vaccinated population and the low number of symptomatic rotavirus infection compared to asymptomatic infections may highlight the vaccination role as an important prevention strategy of acute diarrhea among young children. / A diarreia aguda é a segunda causa de mortes em crianças menores de 5 anos em vários países em desenvolvimento, sendo a infecção pelo Rotavírus a causa mais comum, seguida das infecções por enterobactérias e enteroparasitos. Medidas de saneamento e boa qualidade da água podem diminuir a ocorrência da doença, mas em relação ao Rotavírus a vacinação específica tem papel fundamental. Este estudo teve o objetivo de conhecer as características ambientais e analisar espacialmente a diarreia aguda e as enteroinfecções em lactentes numa situação de uso ampliado da vacina contra o Rotavírus, no município de Laranjeiras/SE. Os lactentes residiam nas áreas de cobertura das Equipes de Saúde da Família, com a faixa etária entre dois e onze meses de idade e foram acompanhados durante 12 meses. Através de um questionário foram obtidos os dados demográficos, socioeconômicos e ambientais e cobertura vacinal contra rotavírus. Foram coletados mensalmente amostras de fezes para realização de exames parasitológicos, bacteriológicos e presença do rotavírus. Para a localização espacial dos domicílios foi utilizado o Sistema de Posicionamento Global (GPS). A análise espacial foi realizada no programa TerraView, utilizando-se o estimador de intensidade Kernel. Foi coletado um total de 1.113 amostras de fezes, sendo 80 associadas a episódios de diarreia. Obteve-se uma incidência média anual de episódios de diarreia de 0,50 ± 0,99/criança/ano. A presença do rotavírus ocorreu em 3,75% dos casos, enquanto que a maior parte (11,25%) das diarreias agudas com causa conhecida aconteceu na presença de infecções helmínticas e por protozoários. No total de 1113 amostras, foram encontrados: Ascaris lumbricoides (5,1%), Endolimax nana (3,0%), rotavírus (2,6%) e Giardia lamblia (0,9%). Não houve influência das condições ambientais no número de episódios de diarreia e das enteroinfecções. Ocorreram pequenas variações na distribuição espacial das enteroinfecções e dos episódios de diarreia, durante os quatro trimestres, destacando-se o centro urbano e áreas adjacentes com maior intensidade. Conclui-se que as características ambientais demonstram homogeneidade em relação às precárias condições de saneamento básico nas moradias dos lactentes, contribuindo para um significativo número de enteroparasitos, até mesmo nesta faixa etária. O baixo número de episódios de diarreia/criança/ano nesta população com ampla cobertura vacinal contra rotavírus sugere o papel da vacinação como uma importante medida de prevenção. O efeito atenuador da vacina também pode ser demonstrado pelo número de casos de infecção por rotavírus assintomáticos em maior número em comparação com os casos sintomáticos.
208

Avaliações econômicas de programas de vacinação: as estimativas de custos em intervenções preventivas / Economic evaluations of vaccination programmes: cost estimates of preventive interventions

Joice Valentim 14 October 2009 (has links)
Esta tese representa o aprofundamento do estudo das estimativas de custos, componente integrante e determinante das avaliações econômicas, enquanto parte do projeto de pesquisa Estudos de custo-efetividade da incorporação de novas vacinas à rotina do Programa Nacional de Imunizações: Rotavírus, Varicela, Pneumocócica conjugada, Meningocócica C conjugada e Hepatite A desenvolvido por solicitação do Programa Nacional de Imunização/PNI da Secretaria de Vigilância em Saúde/SVS do Ministério da Saúde, a partir de 2005. A tese teve como objetivo analisar as condições de uso, dificuldades e repercussões de diferentes métodos de estimativas de custos em estudos de custo-efetividade de vacinas de duas tecnologias específicas, vacinas contra rotavírus e varicela, assim como a relação entre as estimativas de custos e os resultados. As estimativas de custos estão condicionadas pelas características gerais da doença sob análise (aguda no caso de rotavírus e com seqüela no caso de varicela), assim como por questões metodológicas gerais (escolha teórico-conceitual, métodos e fontes de dados) e especificidades do caso brasileiro. Para esta tese, houve maior detalhamento das estimativas de custos diretos no cuidado da doença, com a inclusão de custos específicos do sistema de saúde suplementar para as duas doenças, inclusão de participação pública na dispensação de medicamentos no caso de rotavírus e inclusão de custos de medicamentos do sistema público de saúde no caso de varicela. Como resultado, houve aumento do custo total da doença estimado de 16% para rotavírus e 11% para varicela, assim como aumento de economia (custo total da doença evitado) de 18% e 16%, respectivamente, com a introdução de cada vacina. Apesar do maior detalhamento das estimativas de custos ter reduzido a razão de custo-efetividade incremental em 20% para rotavírus e 4% para varicela, o nível de custo-efetividade dos dois programas de vacinação não foi alterado. Os resultados das avaliações econômicas de vacinação contra rotavírus e varicela mostraram-se mais sensíveis às estimativas de custos do programa de vacinação, em especial o preço da vacina, apontando a relevância do custo da tecnologia sob análise para incorporação em comparação aos demais custos / This thesis represents a deeper study of the cost estimates, an integrant and determinative component of economic evaluations, as part of the project Costeffectiveness studies of the incorporation of new vaccines into the routine of the National Immunisation Program: Rotavirus, Varicella, Pneumococcal conjugate, Meningococcal C conjugate and Hepatitis A. The project has been developed on the request of the National Immunisation Program/PNI of the Secretary of Sanitary Surveillance/SVS of the Ministry of Health since 2005. The objective of the thesis was to analyse the conditions of use, difficulties and repercussions of different cost estimates methods in the cost-effectiveness studies of two specific technologies, vaccines against rotavirus and varicella, as well as the relationship between the cost estimates and the results. The cost estimates are conditioned by general characteristics of the disease under analysis (acute in the case of rotavirus and with long-term disability in the case of varicella), general methodological issues (theoretical choice, methods and sources of data) and specificities to the Brazilian case. This thesis brings a more detailed estimation of direct medical costs, with the inclusion of specific costs of the private health care system for the two diseases, inclusion of public participation for dispensing drugs in the case of rotavirus and inclusion of drugs costs in the public health care system in the case of varicella. As a result, there was an estimated disease total cost increase of 16% for rotavirus and 11% for varicella, as well as increase of savings (disease total cost avoided) of 18% and 16%, respectively, with the introduction of each vaccine. Although the more detailed cost estimates have reduced the incremental cost-effectiveness ratio by 20% for rotavirus and 4% for varicella, the cost-effectiveness level of the two vaccination programs was not altered. The results of the economic evaluations of vaccination against rotavirus and varicella were more sensitive to the vaccination program cost estimates, especially the vaccine price, pointing out the relevance of the cost of the technology under analysis for incorporation comparatively to the other costs
209

Production of recombinant Immunoglobulin A in plants for passive immunotherapy

Juárez Ortega, Paloma 14 April 2014 (has links)
Mucosal passive immunization is the transfer of active antibodies from one organism to the mucosal surfaces of another organism for preventing or treating infectious diseases. Mucosal passive immunization has a great potential for the prevention and treatment of enteric infections like Rotavirus, which causes more than 114 million episodes of diarrhoea annually with a death toll of more than 450.000 per year. However, the high cost of recombinant antibodies with the current manufacturing systems based on mammalian cells hampers the production of the high antibody quantities required for passive immunization strategies. Alternative expression platforms such as plants could provide higher scalability and reduced costs. Moreover, the use of edible plant organs, which are Generally¿Regarded¿As¿ Safe (GRAS), could reduce manufacturing costs even further by easing the requirements for antibody purification. We analyze here the feasibility of utilizing fruits as inexpensive biofactories of human antibodies that can be orally delivered as crude extracts or partially purified formulations in mucosal passive immunization strategies. In the first section of this thesis, the construction of tomato plants producing a model human Immunoglobulin A (IgA) against rotavirus in their fruits is described. As a result, an elite homozygous line was obtained whose fruits produced on average 41 ¿g of IgA per gram of fresh weigh, equivalent to 0.69 mg IgA per gram of dry tomato powder. Minimally processed products derived from IgA¿expressing tomatoes were shown to strongly inhibit virus infection in an in vitro neutralization assay. Moreover, in order to make IgA¿expressing tomatoes easily distinguishable from wild¿type tomatoes, they were sexually crossed with a transgenic tomato line expressing the genes encoding Antirrhinum majus Rosea1 and Delila transcription factors, which confer purple colour to the fruit. The resulting transgenically¿labelled purple tomatoes contained not only high levels of recombinant neutralizing human IgA but also increased amounts of anthocyanins. In the second section of the thesis the composition of IgA¿expressing tomatoes was analyzed in search of possible unintended effects that could compromise the GRAS status of the final product. To this end, transgenic IgA¿tomatoes were compared with wild type tomatoes and also commercial tomato varieties using proteomic and metabolomic approaches. 2D¿DIGE gels coupled with LC¿MSMS for protein identification showed that all the uptrend differential proteins detected corresponded only to immunoglobulin chains or antibody fragments. On the other hand, non¿targeted metabolite data obtained by UPLC¿MS / Juárez Ortega, P. (2014). Production of recombinant Immunoglobulin A in plants for passive immunotherapy [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37015 / TESIS
210

Hygiene Aspects of Greywater and Greywater Reuse

Ottosson, Jakob January 2003 (has links)
Greywater is domestic household wastewater without inputfrom the toilet, i.e. wastewater from sinks, the shower,washing machine and dishwasher in a home. Source separation ofgreywater can be a strategy to enhance recirculation of plantnutrients and/or improve water use. The risk for transmissionof disease when reusing greywater is largely dependent on thecross-contamination by faeces. High levels of faecalindicators, mainly thermotolerant coliform bacteria, have beenreported in greywater, indicating substantial faecal pollution.However, growth of indicator bacteria within the system leadsto an overestimation of thefaecal input and thus the hygienerisk. The faecal input of the greywater in Vibyåsen,Sollentuna, North of Stockholm, was estimated to be 0.04 ±0.02 g faeces person-1 day-1 from the quantification of thefaecal sterol coprostanol, compared to 65 g, 5.2 g and 0.22 gp-1 d-1 using E. coli, enterococci and cholesterolrespectively. Prevalence of pathogens in the population and the faecalload based on coprostanol concentrations were used to form thebasis of a screening-level quantitative microbial riskassessment (QMRA) that was undertaken for rotavirus, Salmonellatyphimurium, Campylobacter jejuni, Giardia intestinalis andCryptosporidium parvum, looking at the treatment required to bebelow an acceptable level of risk (10-3) for reuse or dischargeof the greywater. The different exposure scenarios simulated–groundwater recharge, direct contact, irrigation andrecreational water–showed that a reduction of 0.7–3.7 log was needed for rotavirus, with the measured level offaecal load in Vibyåsen. The other pathogen of concern wasCampylobacter, where a 2.2 log reduction was needed forgroundwater recharge. The infectious dose of Salmonella is highand the excretion numbers of Giardia cysts and Cryptosporidiumoocysts low, resulting in no treatment requirements for theseorganisms under these circumstances. Pathogen input fromcontaminated food via the kitchen sink had a minor effect onthe microbiological quality of the greywater. Studies on virusoccurrence in greywater as well as validation of the faecalload of greywater at another site would give valuable input forfuture QMRAs. Greywater treatment efficiency studies, especially on virusremoval, are scarce and more investigations are warranted.Active sludge may not be a suitable technique for greywater dueto the low carbon content in this flow. Chemical precipitationhas the advantage of removing phosphorus as well as virusesefficiently and it is suggested as one possible method fortreating greywater. Otherwise the most common practice forgreywater treatment in Sweden is soil infiltration. However, itis suggested that the recommendations for wastewaterinfiltration also be observed for greywater, despite the lowfaecal load, due to the simulated results on virus reductionneeded. <b>Key words:</b>greywater, greywater reuse, greywatertreatment, microbial risk assessment, groundwater recharge,irrigation, recreational water, faecal contamination, indicatorbacteria, index organisms, faecal sterols, bacteriophages,enteric pathogens, rotavirus, Salmonella, Campylobacter,Giardia, Cryptosporidium, Legionella / NR 20140805

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