Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Water-borne infections have been a menace in many countries around the globe, claiming millions of lives. Cholera in particular has spread to all continents and now on its seventh epidemic. Although control measures have been continually developed through sanitation, vaccination and rehydration, the infection still devastates populations whenever there is an outbreak. In this research work, mathematical models for cholera transmission dynamics with focus on the impact of sanitation and hygiene, metapopulation spread, optimal control and biological control using a bacteriophage specific for pathogenic Vibrio cholerae are constructed and analysed. Vital analyses for the models are precisely given as well as numerical results depicting long term behaviour and the evolution of populations over time. The results of our analysis indicate that; improved sanitation and hand-hygiene are vital in reducing cholera infections; the spread of disease across metapopulations characterised by exchange of individuals and no cross community infection is associated with synchronous fluctuation of populations in both adjacent communities; during control of cholera, the control measures/efforts ought to be optimal especially at the beginning of the epidemic where the outbreak is often explosive in nature; and biological control if well implemented would avert many potential infections by lowering the concentration of pathogenic vibrios in the aquatic environment to values lower than the infectious dose. / AFRIKAANSE OPSOMMING: Water-infeksies is ’n bedreiging in baie lande regoor die wêreld en eis miljoene lewens. Cholera in die besonder, het op sy sewende epidemie na alle kontinente versprei. Hoewel beheermaatreëls voortdurend ontwikkel word deur middel van higiëne, inentings en rehidrasie, vernietig die infeksie steeds bevolkings wanneer daar ’n uitbraak voorkom. In hierdie navorsingswerk, word wiskundige modelle vir cholera-oordrag dinamika met die fokus op die impak van higiëne, metabevolking verspreiding, optimale beheer en biologiese beheer met behulp van ’n bakteriofaag spesifiek vir patogene Vibrio cholerae gebou en ontleed. Noodsaaklike ontledings vir die modelle is gegee sowel as numeriese resultate wat die langtermyn gedrag uitbeeld en die ontwikkeling van die bevolking oor tyd. Die resultate van ons ontleding dui daarop dat; verbeterde higiëne is noodsaaklik in die vermindering van cholera infeksies; die verspreiding van die siekte oor metapopulaties gekenmerk deur die uitruil van individue en geen kruis gemeenskap infeksie wat verband houmet sinchrone skommeling van bevolkings in beide aangrensende gemeenskappe; tydens die beheer van cholera,behoort die beheermaatreëls/pogings optimaal te wees veral aan die begin van die epidemie waar die uitbreking dikwels plofbaar in die natuur is; en biologiese beheer, indien dit goed geïmplementeer word, kan baie potensiële infeksies voorkom deur ’n vermindering in die konsentrasie van patogene vibrio in die water tot waardes laer as die aansteeklike dosis.

Little is known regarding the impact excessive waterborne metals, like copper (Cu), have on tropical freshwater species. Zebrafish (Dania rerio) only recently became popular as a tool for environmental monitoring, due to their fully sequenced genome. Despite this, little was known regarding the ionoregulatory physiology of zebrafish. I first examined the impact softwater acclimation has on the ionoregulatory capacity of zebrafish, and identified a high degree of phenotypic plasticity associated with changes in both gene and protein expression, which highlighted the need for proper experimental design for studies involving pre-acclimation to softwater. I then examined the acute and chronic effects of waterborne Cu exposure under the influence of both softwater conditions and the addition of protective ions (Na+ & Ca2+) . On an acute timeframe, I found that Na+ provided a greater protective effect than Ca2+ in reducing Cu uptake, which was mimicked during chronic exposure, although the transcriptional effects were not as clear cut. I found that although Na+ and Ca2+ provided protective effects from Cu accumulation, there were still tissue specific and global changes at the transcript level, as determined by microarray analysis. Furthemore, this set of experiments identified the metal- and stress- induced transcriptional effects due to Cu exposure, which is key to identifying gene endpoints of chronic Cu exposure. A final experiment went further and looked at the effects of mixed metal contamination, examining chronic waterborne Cu exposure with interactive effects of elevated dietary Fe on gene expression and tissue metal accumulation. Not only did this experiment highlight that gene expression is not necessarily reflected in protein abundance/activity, but also demonstrated that high dietary Fe can significantly alter the transcriptional expression pattern of Cu transporters in the gill, liver, and gastrointestinal tract. This thesis has made significant steps in identifying viable gene endpoints of Cu toxicity. / Thesis / Doctor of Philosophy (PhD)

No description available.

To protect public health, drinking water systems are monitored for indicator organisms that correlate with fecal contamination and suggest the presence of human pathogens. Total coliforms, fecal coliforms, and E. coli are the most commonly used indicator organisms. These bacteria generally colocate with fecal pollution, but some limitations exist. In particular, the ability of indicator bacteria to predict the presence of enteric viruses is questionable because of distinct transport and survival characteristics of bacteria and viruses. Although viral indicators of enteric viruses have been proposed, none have been implemented into the current regulatory framework. In this thesis, the correlation of bacteria and viruses in drinking water sources and treatment systems is reviewed, and the potential of Torque Teno virus (TTV) to qualify as an indicator virus is discussed. TTV is unique among enteric viruses as it infects approximately 80% of healthy individuals worldwide, is transmitted by the fecal-oral route, causes no observable illness, and lacks seasonal fluctuations.

Made available in DSpace on 2016-04-27T18:15:45Z (GMT). No. of bitstreams: 1 Andre Veloso de Melo.pdf: 11528174 bytes, checksum: af1410179b57da5cd87d5d37825318e7 (MD5) Previous issue date: 2014-10-27 / This study aims to analyze the conditions of water resources; sanitation and occurrence of waterborne diseases in districts of Águas Negras and Paracuri in Belém do Pará. As part of this study, the literature survey was conducted to benchmark theoretical, the Geography of Health, the importance of water resources for humans, sanitation of waterborne and location of the study area diseases. For the preparation of statistical data relating to sanitation and waterborne diseases in Brazil, in the state of Pará in Belém and information from official bodies such as the Brazilian Institute of Geography and Statistics (IBGE), Ministry of Health and were collected Department of Public Health (SESPA). The application of fifty questionnaires found that the socio economic, sanitation and waterborne diseases conditions, with residents was also conducted. It is concluded that the basic sanitation in Brazil is still very poor, especially in the North and Northeast; it directly influences the number of notifications of waterborne diseases in the country. In the neighborhoods of Paracuri and blackwater, by analyzing the interviews that there is a lack of sewage collection and treatment, regular water connections incidence of waterborne diseases causing large number of hospitalizations / de veiculação hídrica e da localização da área de estudo. Foram também analisados os dados estatísticos referentes ao saneamento básico e das doenças de veiculação hídrica no Brasil, no Estado do Pará e em Belém, cujas informações foram coletadas de órgãos oficiais, como o Instituto Brasileiro de Geografia e Estatística (IBGE), Ministério da Saúde e da Secretaria de Saúde Pública do Pará (SESPA). Foi realizada ainda a aplicação de cinquenta questionários, visando analisar as condições sócio econômicas, de saneamento e das doenças de veiculação hídrica, junto dos moradores. Conclui-se que o saneamento básico no Brasil ainda é muito deficiente, principalmente nas Regiões Norte e Nordeste, com isso influenciando diretamente, o grande número de notificações de doenças de veiculação hídrica no país. Nos bairros dos Paracurí e de Águas Negras, a partir da análise das entrevistas, observa-se que há falta de coleta e tratamento de esgoto, de ligações regulares de água, com a incidência de doenças de veiculação hídrica ocasionando grande número de internações

A contaminação de água subterrânea por coliformes fecais em propriedades rurais está diretamente relacionada com o saneamento básico rural oferecido, assim como as doenças de veiculação hídrica contraídas por essas populações. Esta pesquisa analisa a contaminação da água de consumo humano proveniente de poços, considerando os índices de potabilidade descritos na Portaria do Ministério da Saúde nº 2.914 e na Resolução CONAMA nº 398. Tem-se como estudo de caso uma área rural no município de Caxias do Sul, estado do Rio Grande do Sul, inserida na da bacia hidrográfica do arroio Marrecas. Foram realizados estudos por meio de informações contidas em relatórios técnicos, normatizações federais e bibliografias especializadas, para contextualização, conceituação e teorização de saneamento básico rural, qualidade e contaminação da água subterrânea, doenças de veiculação hídrica e poços. Mediante o uso do estimador de densidade Kernel, levantou-se o número de residências a serem entrevistadas. Durante o processo de entrevistas, averiguou-se a existência de saneamento básico rural nas propriedades, porém a maioria dos poços não estavam protegidos do acesso e/ou de serem contaminados por animais. Isto justificou a necessidade de realização de análise da qualidade da água subterrânea consumida por meio de poços particulares. Os resultados das entrevistas diagnosticaram uma população ambientalmente consciente sobre a preservação do meio e sobre a qualidade da água consumida. Contudo, os resultados das análises indicaram que a água ingerida estava contaminada por coliformes, assim como também houve relatos de doenças de veiculação hídrica, confirmando o saneamento deficiente em algumas propriedades rurais. / The contamination of groundwater by fecal coliforms in rural properties is directly related to the available basic rural sanitation, as well as to water-borne diseases contracted by these populations. This research analyzes the contamination of potable well water, applying the potability indicators described in the Ministry of Health Directive Nº. 2914 and the Brazilian Environment Council (CONAMA) Resolution No. 398. A rural area in the city of Caxias do Sul, Rio Grande do Sul, located within the hydrographic basin of the Marrecas stream, was used as the case study. Studies were conducted by using information contained in technical reports, federal guidelines, and specialized bibliographies, for the context, concepts and of basic rural sanitation, quality and contamination of groundwater, waterborne diseases and wells. The number of households to be interviewed was determined by using the Kernel density estimator. During the interview process, the existence of basic rural sanitation was verified in the properties, however, a majority of the wells were not protected from the access and/or from being contaminated by animals. This justified the need for conducting the analysis of the quality of groundwater consumed by way of individual wells. The interviews resulted in the diagnostic of an environmentally conscious population, aware of preserving the environment and of the quality of water consumed. However, the results of the analyses indicated that the drinking water was contaminated by coliforms, and there were also reports of waterborne diseases, confirming the poor sanitation in some rural properties.

Lack of safe drinking water and lack of water hygiene literacy contribute to a large disease burden in rural areas of Africa, and children suffer disproportionately more than adults from diarrheal diseases caused by nonpotable water. Research is needed to help merge education and water sanitation to provide more effective methods of preventing diarrheal diseases. The ecological model and hygiene improvement framework were used to guide the study. The purpose of this phenomenological study was to describe the shared experiences of people participating in the water hygiene education program provided by Lifewater International. Lifewater is a nonprofit organization focused on improving access to clean water and increasing water hygiene literacy in rural parts of developing countries. Individual interviews were conducted with six Lifewater program participants, using the Delphi sampling technique. After I transcribed and thematically analyzed data for codes, three main themes were identified that motivated Lifewater partners and members of their community to change behavior: improving their children's health, saving time and money, and being a better Christian. The most meaningful part of participating in the program is that they use the information to improve the lives of those in their communities. In addition to making curricula for the Lifewater organization and its partners more streamlined, if the lessons are more culturally relevant, people are more likely to accept the behavior changes being taught, which can also influence the behavior change. Culturally relevant curriculum could help increase the access to and knowledge of clean water in developing areas, which contributes to the United Nation;s Millennium Development Goals, and thus promotes social change.

During the 1980’s millions of households in Bangladesh switched from drinking surface water to private groundwater wells to reduce their exposure to fecal microorganisms. Sadly, this switch to shallow groundwater resulted in the largest example of drinking water poisoning in history, with approximately 100 million people exposed to high concentrations of naturally occurring Arsenic in the groundwater. Spatial distribution of Arsenic in the shallow aquifers tends to be patchy, so the most economical mitigation option has been lateral switching from high Arsenic wells to nearby low Arsenic wells. The recently developed Arsenic flushing conceptual model, which explains the spatial distribution of Arsenic throughout the shallow aquifers in Bangladesh, suggests however, that low Arsenic zones are recharged via coarse-grained, rapid flow pathways and therefore represent a higher risk for waterborne pathogens. The objectives of this dissertation are to evaluate new methods for sampling and detection of waterborne pathogens, while also identifying sources of fecal contamination and transport pathway(s) to private wells emplaced within the shallow aquifers. It was demonstrated that private wells are broadly contaminated with E. coli, with prevalence ranging from 30 to 70%. The fact that E. coli was detected more frequently in private wells than sealed monitoring wells (p<0.05) suggests that well construction and/or daily pumping contribute to fecal contamination of the private wells. Using DNA-based molecular fecal source tracking, contamination was demonstrated to originate from human fecal waste. Unsanitary latrines, which spill effluent onto the open ground, were demonstrated to cause elevated levels of fecal bacteria in ponds, found in every village. These ponds were demonstrated to have an influence on concentrations of fecal bacteria to at least distances of 12m into the adjacent aquifer. In a culture where latrines, private wells and ponds are frequently clustered closely together, these findings suggest that improvements in the management of human fecal waste changes in placement and construction of private wells could substantially reduce exposure of people to fecal pathogens. Fecal contamination was found to be pervasive in low Arsenic, unconfined, shallow aquifers, and therefore gains from well switching to avoid Arsenic need to be balanced with the risk of consuming waterborne pathogens.

The overall objective of the work described in this thesis was to examine the effects of both waterborne and dietary routes of exposure to fathead minnow (Pimephales promelas) when exposed to complex metal mining mixtures. This was conducted using a 21-day, multi-trophic, short-term fathead minnow (FHM) reproductive bioassay. The endpoints that were measured were used to assess the effects on multiple levels of biological organization (sub-organismal to population endpoints). The first phase of this research was conducted in situ using environmentally realistic concentrations of 3 separate metal mining effluents [20% surface water effluent (SWE), 30% mine water effluent (MWE), 45% process water effluent (PWE)] from Sudbury, Ontario, Canada. Metals were analyzed in several media (water, sediments) and tissues (biofilm, Chironomus dilutus, female fathead minnow carcass, ovaries, liver and gills). The incorporation of the biofilm (primary producers) into the bioassay also added another level of organization that was novel to this study. Significant increases in metal concentrations were observed in the water and biofilm tissues in all treatments [SWE, MWE, PWE], compared to reference. Cobalt and nickel increased significantly in C. dilutus tissues in SWE (1.4-fold and 1.5-fold respectively), and copper and selenium in PWE (5.2-fold and 3.3-fold respectively), however no significant increases occurred in MWE compared to reference. There were no significant increases in metal concentrations in female FHM tissues (carcass, liver, gonads, gills) in any of the treatments, suggesting that metal bioavailability was reduced. Cumulative number of eggs per female per day increased significantly (+127%) after exposure to SWE and decreased significantly (-33%) after exposure to PWE when compared to the reference fish. Mean total number of days to hatch was also reduced in PWE compared to reference. In order to gain a better understanding of the routes of exposure causing toxicity in FHM, the second phase of this research examined the effects of exposure through diet, through water or through both using a fully factorial food exposure design in a laboratory setting. In this experiment we pre-exposed C. dilutus to both 45% PWE and laboratory control water until they reached the 3rd-4th instar stage of development (approximately 21 days) where they were collected and frozen until the start of the FHM reproductive bioassay. We further examined the role of food quality on fish toxicity by assessing differences between multi trophic (where fish were fed both a live and frozen diet of C. dilutus) in the laboratory. This research was conducted at the Toxicology Centre in Saskatoon, Saskatchewan, Canada. The results showed that significant effects were observed when fish were fed a live diet versus a frozen diet. Condition factor and body weight increased, although inconsistent effects were observed for liver somatic index (LSI) in fathead minnows in both experiments when exposed to one or both routes of exposure. Cumulative total egg production and cumulative spawning events were both significantly affected by both waterborne and dietborne exposures with the greatest effects seen in the multi-trophic streams and particularly when fish were fed a live diet. This significance of this research has demonstrated the importance of including both routes of exposure when assessing effects of mine effluent. This research also shows that the artificial stream technology is a useful tool in isolating the effects of a particular point source input (metal mining mixtures) when a system is highly confounded. The results suggest that under environmentally relevant exposure conditions, trophic transfer and live diet may lead to greater reproductive effects and increased fish toxicity. This also suggests that trophic transfer is an important route of exposure that is virtually impossible to attain using typical laboratory bioassay techniques (food-borne study using artificial diets or waterborne exposures only).

Yersinia enterocolitica are potentially pathogenic bacteria transmitted through the fecal oral route. Typical disease symptoms include those associated with gastrointestinal disease, although infection can also lead to more serious and invasive illnesses, particularly in sensitive populations. Previous surveys have detected Y. enterocolitica in surface water in various parts of the world, and studies have found drinking untreated water to be a possible risk factor for Y. enterocolitica infection. Methods available for the detection of Y. enterocolitica have been developed primarily for food and clinical samples and have not been tested extensively with water. More commonly used methods include culture based isolation of Yersinia spp. and polymerase chain reaction (PCR) based detection of Y. enterocolitica. Reports suggest that culture based methods available for the isolation of Y. enterocolitica may not be effective for environmental samples. Strain isolation using culture based methods is important, so that further subtyping information can be obtained for epidemiological investigations. In contrast, PCR based detection is more rapid, of higher throughput, can be highly specific and can target pathogenic strains within a species. The overall objective of this work was to evaluate culture based and PCR based methods for the detection of Y. enterocolitica in water, and to examine its prevalence in the Grand River watershed in Southwestern Ontario, Canada. Surface water in this watershed is used to provide all or part of the drinking water for approximately 500,000 people, as well as for recreational purposes. It is also one of the most heavily impacted watersheds in Canada by both agricultural and urban activities. Culture based studies compared two selective agars and four enrichment broths. Results showed that Cefsulodin Irgasan Novobiocin (CIN) agar and modified tryptic soy broth (mTSB) had greater potential for recovering Y. enterocolitica from surface water. Consequently, enrichment in mTSB followed by growth on CIN agar was used to isolate Yersinia from the Grand River. Yersinia strains were isolated from 52 out of 200 (26 %) surface water samples collected over a 17 month period. No seasonal trends were observed in isolation rates. Species isolated were typically considered to be non pathogenic species, although recent evidence suggests they may have potential virulence to humans. The majority of these strains have been found by other groups in surveys of aquatic environments. PCR methods developed targeted two Y. enterocolitica virulence genes: the ail gene, located in chromosomal DNA; and the yad A gene, located on a virulence plasmid. In surface water collected from the Grand River, the ail gene target was detected in 121 samples out of 319 (38 %) over a 29 month period and the yadA gene target was detected in 44 samples out of 206 (21 %) over a 20 month period. Both genes were detected more frequently when the water temperatures were colder. PCR-based studies conducted were quantitative, which has not previously been done with water samples. The median and maximum concentrations in samples positive for the ail gene were 40 and 2,000 cells/100 mL, and in samples positive for the yadA gene were 32 and 3,276 gene copies/100 mL, respectively. Overall results demonstrated that culture based methods are less sensitive than PCR based detection methods for specific detection of pathogenic Y. enterocolitica, suggesting that previous culture based surveys may have underestimated their potential prevalence. Furthermore, potentially pathogenic Y. enterocolitica may be present in the Grand River watershed. While Y. enterocolitica is relatively easily inactivated by traditional disinfection methods used in drinking water treatment processes, it is possible their presence poses a concern for recreational users and individuals drinking untreated water. This study suggests that further investigation is necessary to evaluate possible health risks associated with the occurrence of potentially pathogenic Y. enterocolitica in the Grand River. This work assists with the development of methods and information gathering for an emerging waterborne pathogen that has not been surveyed in the Grand River watershed, nor quantitatively surveyed in any water previously. Findings provide important information for drinking water providers and public health investigations.