Lack of affordable feeds is one of the major constraints facing small-scale fish farmers in Tanzania. This study evaluated the suitability of moringa leaf meal (MLM), cassava leaf meal (CLM) and cassava root meal (CRM) as novel ingredients in Nile tilapia, Oreochromis niloticus diets. Each of the ingredients was processed in an attempt to remove the most significant antinutritional factor. A series of five experiments was conducted in a recirculation system using juvenile O. niloticus. The fish were fed isonitrogenous (30g 100g-1), isolipidic (10g 100g-1) and isoenergetic (18 kJ g-1) diets containing graded levels of the processed ingredients to their apparent appetite but not exceeding 10% of their body weight for a period of 8 weeks. Processing led to the removal of 0.3% of saponin from MLM and 60% and 90% of hydrogen cyanide from CLM and CRM respectively. The contents of other inherent antinutritional factors such as phenols, tannins and phytic acid were little affected. Processed MLM, CLM and CRM had 31.1/29.0/1.5g 100g-1 of crude protein, 5.9/10.2/2.4g 100g-1 of crude fibre and 20.1/19.7/15.8k Jg-1 of gross energy. The content of sulphur amino acids was higher in CLM (0.47%) than in MLM (0.23%). Digestibe protein and digestible energy was higher in MLM (25.71g 100g-1/15.44kJ g-1) than in CLM (12.71g 100-1/9.16kJ g-1). CRM had a digestible energy content of 13.5kJ g-1. Inclusion of either of the leaf meals, even at the lowest level of 15g 100g-1 of total dietary protein, led to a significant reduction in feed intake, growth and feed utilisation. Liver and small intestine did not show any histopathological changes which could be linked to dietary treatment. Conversely, cassava root meal could replace up to 75% of wheat meal in the diet without significantly affecting performance. The performance of leaf meals was marginally improved by a combination of blending and feeding stimulants, whereby a blend containing 1 part MLM and 2 parts CLM could provide up to 20g 100g-1 of dietary protein without significantly reducing performance. Biological and economic performance of practical diets containing 30-50g 100g-1 of dietary protein from moringa and cassava blends (LMB) with feeding stimulants was significantly lower than a fishmeal-meal based diet (FM) but comparable to a soybean meal-based diet (SBM). The suitability of MLM and CLM as novel protein sources in O. niloticus diets will depend on 1) improving reduction/removal of inherent antinutritional factors in MLM and CLM as well as improving digestibility of CLM. On the other hand, the suitability of CRM as a carbohydrate energy source will depend on the availability of cost effective protein sources due to its low protein content.

Thesis (MScAgric)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Forming part of a conservation programme, this study was concerned with two species of Cichlid fish (Oreochromis mossambicus and O. ni/oticus), which were brought into contact with each other by unnatural ways. They are now hybridizing to some extent and there is also evidence that the foreign O. ni/oticus may out compete the native O. mossambicus. To cast light on what the current distribution is of both these species and the hybrids in Southern Africa, it is important to identify specimens very accurately. In attempting to find genetic markers to distinguish between two species of Cichlids we tested 20 microsatellite dinucleotide (CAn) repeats during a preliminary study and found five of these promising to exhibit little intra-specific genetic diversity but large genetic variation between species. We amplified these five loci in 145 individuals from 10 populations, which included the two species and their hybrids. Exact sizes of the fragments were determined using an automated DNA sequencer. Between the two species, allele sizes were overlapping, but when data were analyzed by statistical models, the differences could be seen for populations, however on individual level there was overlap between the species. The hybrids were found to be intermediate positioned between the two pure species. Our attempt to assign individuals to populations provided doubtful results. Thus, using this set of markers, populations can be ascribed to one of these species, but not individuals by themselves. / AFRIKAANSE OPSOMMING: As deel van 'n natuurbewarings program, word daar in hierdie studie twee spesies van vis ondersoek was in kontak met mekaar gekom het op onnatuurlike wyse. Hierdie twee visspesies vanuit die CICHLIDAEfamilie (Oreochromis mossambicus en 0. ni/oticus) kan hibridiseer wanneer hul saam voorkom, maar dit is ook bekend dat die uitheemse O. ni/oticus die inheemse O. mossambicus kan bedreig in terme van leefruimte, kos en broeispasie. Om die voorkoms van hibriede tussen die twee spesies te ondersoek in Suider Afrika se varswater opvangsgebiede, is dit baie belangrik om individue baie akkuraat te identifiseer. In hierdie poging om genetiese merkers te vind wat die twee spesies van mekaar onderskei, het ons 20 mikrosateliet di-nulkleotied (CAn) herhalende volgordes op verskillende loci ondersoek. Vyf daarvan het belowend voorgekom om as spesie spesifieke merkers te dien. Die fragmente op die vyf loci is ge-amplifiseer in 145 individue vanuit 10 populasies. Presiese groottes van die fragmente is bepaal met behulp van 'n ge-outomatiseerde DNA volgorde bepaler waarna genotiepes vir elke individu toegeken is. Tussen die twee spesies het alleel groottes oorvleuel, maar wanneer data geanaliseer word met behulp van statistiese metodes, was verskille tussen die spesies duidelik op populasie vlak. Die hibriede het intemediêr tussen die twee spesies voorgekom. Dus met behulp van hierdie stel merkers kan onderskei word tussen die twee spesies op populasie vlak, hoewel individue nie op sig self identifiseer kan word nie.

L'épidémie de West-Nile en Amérique du Nord en 2002, qui a touché plus de quarante états aux Etats-Unis, a conduit les Agences de santé à s'interroger sur le risque d'émergence, à l'extérieur de la zone intertropicale, de zoonoses vectorielles. Cette épidémie associée au changement climatique, a bien mis en évidence le rôle central de l'avifaune migratrice dans la diffusion du virus. La biologie des oiseaux, tout particulièrement le phénomène migratoire, permet un transport des virus sur de longues distances et entre espèces très diversifiées. Le Moyen-Orient, qui est situé au carrefour de différents continents, est extrêmement propice à la propagation des virus émergents dans les pays du Nord. La circulation du virus West Nile a été rapportée dans différents pays de la région, tels que l'Egypte, Israël, Liban, Irak, Emirats Arabes Unis et Iran. Saidi et al. (1970) ont montré la présence d'anticorps anti-virus du Nil occidental au sein de la population de la côte caspienne (Nord de l'Iran), des provinces du Khorassan (Nord-Est) et du Khuzestan (Sud-Ouest). Notre étude, conduite dans le cadre d'un programme associant TIMC-IMAG UMR 5525 UJF CNRS VetAgroSup, le Réseau International des Instituts Pasteurs et le Centre National d'Etudes Spatiales, vise: (i) à caractériser la circulation du virus de West-Nile au sein des populations équines d'Iran ; et (ii) et à modéliser l'impact sanitaire de l'environnement et du climat sur la transmission. Les résultats acquis permettent d'apprécier le risque associé à la dissémination spatio-temporelle du virus par les oiseaux migrateurs. Une attention toute particulière est portée à l'étude des déterminants environnementaux et climatiques susceptibles d'accroitre le potentiel de transmission du virus. / The outbreak of West Nile in North America in 2002, which affected more than forty states in the United States, has led Public Health Agencies to adress the risk of emergence of vectorial zoonosis, outside of the area tropical. This epidemic events associated with climate change, has highlighted the central role of migratory birds in spreading the virus. The biology of birds, especially the migratory phenomenon, ensures a transport of viruses over long distances and across very diverse species. The Middle East, located at the crossroad between different continents, is extremely prone to the spread of zoonotic diseases, like West-Nile, in the Northern countries. The circulation of WN virus has reported from different countries in the region; such as Egypt, Israel, Lebanon, Iraq, United Arab Emirates and Iran. Saidi et al. (1970) have established the presence of antibodies to West Nile among the population of the Caspian coast (northern Iran), the provinces of Khorasan (Northeast) and Khuzestan (Southwest). Our study, in the framework of a collaborative programme associating TIMC-IMAG UMR CNRS UJF VetAgroSup, International Network of Institut Pasteur and Centre National d'Etudes Spatiales, aim to: (i) characterizing the circulation of the virus from West Nile in the equine population of Iran, and (ii) and modelling the health impact of the environment and climate on the transmission. The results obtained allow us to assess the risk associated with spatial and temporal spread of the virus by migratory birds. Particular attention is given to the study of environmental and climatic determinants that may increase the potential for transmission.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 135-137. / by Katherine Oven Thompson. / M.S.

Text in English / Ruti dam is located on the Nyazvidzi river, and is home to many Nile crocodiles (Crocodylus niloticus), which rely on fish and livestock for food. The community also relies on the dam and riverine for its resources. The investigation of crocodile impacts on humans and livestock, the trends and seasonality of attacks and identification of other predators resulted in formulation of research. The field interviews, using a structured questionnaire, field observation and focused group discussions were mainly used in data collection. Threats posed by crocodiles were identified as mainly human and livestock depredation, which has increased since the introduction of the crocodiles into the dam. The crocodile depredation varies between seasons, due to differences in water levels in the dam, and availability of alternative water sources. The attacks were mostly during the dry season and at the beginning of the wet season, when there were fewer water sources and when the water was dark and murky. The study assessed the human-crocodile conflict situation, based on interviews with the local residents and focused group discussions with fishermen. The conflict arose with livestock farmers after animal kills and fishermen, in cases of death, injury or damage to fishing gear. The killing of either humans or livestock was during the early hours of the day. Hostile attitudes of the residents towards crocodiles were high (83.9%). The majority, given the chance to eliminate the crocodile, would do so mercilessly. These negative attitudes can only be ameliorated when the damage is adequately compensated. The absence of compensation has increased the conflict, though no retaliation is taken against the crocodiles. The crocodiles prefer cattle in their kills (41% and 48%), followed by goats (38% and 25%), and, lastly, humans, in Buhera Rural District Council (BRDC) and Gutu Rural District Council (GRDC), respectively. Livestock farmers who stay close to the dam and Nyazvidzi suffer more losses, as their animals are more oftenly exposed to the dangers of crocodile predation, than those of farmers who stay far away, as they can use alternative water sources, and their animals are less likely to be exposed to the dangers of the crocodiles. The settlement pattern in BRDC has had an influence on predation. The farmers have also developed new livestock management techniques to reduce the loss of livestock. The fishermen suffer net damage on most occasions of their fish catches, as the crocodile might have learnt to follow the plastic floats on the water for easier prey from the nets. The fishing strategies have been developed to reduce fish loss. The death of fishermen is mostly that of people who enter the dam without canoes; no deaths were recorded of fishermen in canoes. Also, no capsizing of canoes has been recorded in Ruti dam, as fishermen always move in groups. Attacks in the Nyazvidzi River were on women and schoolchildren. Hyenas, as with the crocodile, have contributed to high kills of livestock (71.1%) and human kills were also reported in 2012 and July 2013. Though conflicts exist in the area, recommendations were made which might help to lower the conflicts. Educational campaigns and direct incentives from predator losses were identified as the main factors in conflict resolutions. The information on the importance of the predators and how or when it kills should be taught to respondents as they will be able to protect their livelihood. / Environmental Sciences / M. Sc. (Environmental Management)

Text in English / Ruti dam is located on the Nyazvidzi river, and is home to many Nile crocodiles (Crocodylus niloticus), which rely on fish and livestock for food. The community also relies on the dam and riverine for its resources. The investigation of crocodile impacts on humans and livestock, the trends and seasonality of attacks and identification of other predators resulted in formulation of research. The field interviews, using a structured questionnaire, field observation and focused group discussions were mainly used in data collection. Threats posed by crocodiles were identified as mainly human and livestock depredation, which has increased since the introduction of the crocodiles into the dam. The crocodile depredation varies between seasons, due to differences in water levels in the dam, and availability of alternative water sources. The attacks were mostly during the dry season and at the beginning of the wet season, when there were fewer water sources and when the water was dark and murky. The study assessed the human-crocodile conflict situation, based on interviews with the local residents and focused group discussions with fishermen. The conflict arose with livestock farmers after animal kills and fishermen, in cases of death, injury or damage to fishing gear. The killing of either humans or livestock was during the early hours of the day. Hostile attitudes of the residents towards crocodiles were high (83.9%). The majority, given the chance to eliminate the crocodile, would do so mercilessly. These negative attitudes can only be ameliorated when the damage is adequately compensated. The absence of compensation has increased the conflict, though no retaliation is taken against the crocodiles. The crocodiles prefer cattle in their kills (41% and 48%), followed by goats (38% and 25%), and, lastly, humans, in Buhera Rural District Council (BRDC) and Gutu Rural District Council (GRDC), respectively. Livestock farmers who stay close to the dam and Nyazvidzi suffer more losses, as their animals are more oftenly exposed to the dangers of crocodile predation, than those of farmers who stay far away, as they can use alternative water sources, and their animals are less likely to be exposed to the dangers of the crocodiles. The settlement pattern in BRDC has had an influence on predation. The farmers have also developed new livestock management techniques to reduce the loss of livestock. The fishermen suffer net damage on most occasions of their fish catches, as the crocodile might have learnt to follow the plastic floats on the water for easier prey from the nets. The fishing strategies have been developed to reduce fish loss. The death of fishermen is mostly that of people who enter the dam without canoes; no deaths were recorded of fishermen in canoes. Also, no capsizing of canoes has been recorded in Ruti dam, as fishermen always move in groups. Attacks in the Nyazvidzi River were on women and schoolchildren. Hyenas, as with the crocodile, have contributed to high kills of livestock (71.1%) and human kills were also reported in 2012 and July 2013. Though conflicts exist in the area, recommendations were made which might help to lower the conflicts. Educational campaigns and direct incentives from predator losses were identified as the main factors in conflict resolutions. The information on the importance of the predators and how or when it kills should be taught to respondents as they will be able to protect their livelihood. / Environmental Sciences / M. Sc. (Environmental Management)

Reproductive containment in farmed fish is highly desired for sustainable aquaculture to prevent genetic introgression with wild conspecifics and enhance productivity by suppressing sexual maturation. A number of strategies have already been implemented or have been tested in commercially important fish (e.g. triploidy, monosexing, hormonal therapies); however, they either do not result in 100% containment, or they cannot be applied to all species. One promising new approach consists in disrupting primordial germ cells (PGCs), at the origin of germline cells, to induce sterility. The work carried out in this doctoral thesis aimed to investigate the genes involved in the survival of germ cells and subsequently conduct a functional analysis of candidate genes using CRISPR/Cas9 gene editing system to ultimately provide the basis for the development of a novel sterilisation technique. Nile tilapia was chosen as the experimental animal as it is a major aquaculture species worldwide and the control of reproduction plays a critical role in the farming productivity in this species. In addition, the species has clear advantages as its whole genome sequence is accessible, the generation time is relatively short and zygotes can be available all year round. Initially, a panel of 11 candidate genes with reported roles in survival of PGCs was investigated during the ontogenic development which led to the selection of piwi-like (piwil) gene as a target for genome editing. Then, high temperature was tested as a means to induce germ cell loss to better understand the mechanism underlying germ cell survival and apoptosis, and this study confirmed the functional importance of piwil genes in relation to germ cell loss and proliferation. In addition, the study suggested potential subfunctionalisation within the Bcl-2 gene family which requires further investigation. The next step aimed to optimise the CRISPR/Cas9 gene editing method by improving the microinjection system and testing different concentrations of sgRNAs. Over 95% of injected embryos showed on-target mutation in piwil2 via zygote injection of CRISPR/Cas9 reagents and complete KO larvae were shown in half of the mutants, producing putative sterile fish. However, there was no clear association between the phenotypes in PGCs and the mutation rate. Further comparative studies of mutant screening methods including T7E1, RGEN, HRMA, fragment analysis and NGS revealed that the genotypes of F0 are highly mosaic, suggesting that deep sequencing is recommended for accurate and high throughput F0 screening and further improvement for predictable genome editing is required for a reliable gene functional analysis in F0. In summary, the current thesis provided new scientific knowledge and supporting evidence for the use of the CRISPR/Cas9 gene editing platform to study gene function associated with sterility, with the ultimate goal to develop an alternative sterilisation method in fish.

In general Nile Crocodile Crocodylus niloticus numbers in South Africa appeared to have recovered after persecution and eradication attempts during the last century. Within the last decade, however, the future of South Africa’s Nile Crocodiles seems ominous yet again, as they are faced with renewed threats including habitat destruction and/or degradation. The primary Nile Crocodile populations in South Africa, Kruger National Park, Lake St Lucia and Ndumo Game Reserve are all currently threatened as a result of anthropogenic actions. The vulnerability of South Africa’s major Nile Crocodile populations has highlighted the need for further studies on and assessment of other populations in the country. This study was conducted from April 2009 to July 2010 on the Nile Crocodile population found in Pongolapoort Dam. The aim of the study was to obtain baseline data on the ecology of this previously unstudied population, which included obtaining an estimate of population size and structure, the reproductive dynamics and success of the population, general distribution of the population in the dam and seasonal changes in their distribution. The impact of the impoundment on this population was also discussed. Initial surveys from 1981 and 1989 described few crocodiles in the system. Currently Pongolapoort Dam contains a significant Nile Crocodile population that was previously not considered as substantial. A conservative estimate of 273 Nile Crocodiles was determined for Pongolapoort Dam in 2009-2010. A combination of survey methods allowed for a population structure to be gauged and identified as having 116 juveniles (< 1.2 m), 75 sub-adults (1.2 - 2.5 m), and 82 adults (> 2.5 m). Currently the population has a high percentage of juveniles (42 %), suggesting a growing population, with the proportion of adults (30 %) able to sustain a viable population into the future. From the construction of the Pongolapoort impoundment in 1972 the water level has fluctuated and the surrounding landscape has been altered. As a result the Nile Crocodiles residing in the area had to adapt to the ever changing environment. Their general distribution changed after dam wall completion, when the dam began to fill. First distributional change was a movement out of the gorge section into the newly flooded areas. After the Domoina floods (1983) the dam level rose by over 70 % and the crocodiles moved into the current inlet section. The majority of the crocodile population is now found in the inlet section of the Pongolapoort Dam, utilizing the Phongola River in summer months and residing in the inlet section as historical basking sites during the winter months. Investigating reproductive ecology is essential in order to access the population dynamics of an unstudied population, as reproductive output can be a measure of population health. Reproduction and nesting of Nile Crocodiles in Pongolapoort Dam, and in particular determining the effects of the impoundment on these were investigated. No previous reproductive effort had been documented prior to this study. Crocodiles congregated at a major basking site, where the Phongola River entered the dam, during August 2009 with a 576 % increase in numbers. This signalled the commencement of the breeding season. Females with transmitters made short trips upstream during this time. In November, with the first rains, the river rose and the majority of crocodiles moved up the inlet, and females established nests. Three major nesting areas were identified, two of which were located in the river inlet to the dam. Approximately 30 nesting females were identified during the 2009/2010 nesting season. All nesting areas identified had been used in prior nesting seasons. Nests were located on a variety of substrate types, from clay formed through culluvial and fluvial deposits to course river sand. Several of the nests were predated by Water Monitor (Varanus niloticus). Although the number of nesting females was greater than expected, during the study period there was a total recruitment failure of nests along the river due to a flash flood of the Phongola River in January 2010, destroying all nests prior to hatching. As several juvenile crocodiles were found during surveys, this preliminary study suggests that the Pongolapoort Dam Nile Crocodile population has a relatively high potential reproductive out-put, although their annual successes may vary greatly because of loss of nesting sites because of water level fluctuations and predation. It appears that the impoundment has generally had a positive impact on this Nile Crocodile population recruitment although suitable nesting sites may become limited. There appear to be no current threats to the Nile Crocodile Pongolapoort Dam population, however illegal gill-netting and poaching on the dam and surrounding reserves is on the rise and if not prohibited can result in future problems. A second concern is the high abundance of alien invasive plants that dominate the area, most notably in the river inlet section, the Nile Crocodiles main nesting area. The water quality entering the system is unknown at present and should be tested in future studies to assess whether there may be any reason for concern. In general the Nile Crocodile population in Pongolapoort Dam appears to be one of the least vulnerable and most reproductively successful in South Africa at present. The population has increased dramatically as a result of successful reproductive output even with the ecosystem changes as a result of the impoundment of the Phongola River. It is unlikely that the population increase was as a result of immigration from surrounding areas as the dam wall is a substantial barrier between the dam and the lower crocodile population of Ndumo Game Reserve some 70 km downstream. The high number of crocodiles found through all size classes, juveniles to large adults, also suggests that this population has been stably increasing for a number of years and has a sustainable breeding population. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

The main goal of thesis is to explore the changing global epidemiological situation depending on climate changes and to map trends of changes in epidemiological situation. A sub-objective is to find out if there are differences in the geographical distribution of the incidence of West Nile Virus (WNV) in the period 2004-2014 next to map surveillance, to propose options for improving prevention in a changing geographical distribution, to describe cases of the diseases reported in the Czech Republic, to determine whether in the Pilsen and Budweis medical facilities are routinely investigating also on detection of WNV infection and finally to chart the WNV infection rate and its causes in horse breeding. Influence of climate change on distribution of WNV can be very well observed. This change is mainly due to settlement of new countries by the originator and also reservoirs which are moving further to the north or south becouse of climate. Distribution of WNV to the new countries is also supported by the changing of landscape, mainly due to the changing climate. The changes of migration routes of migratory birds which are also affected by climate changes have also the effect on changing geographic distribution. The globalization of the world is also mostly responsible for change of distribution. The change of epidemiological situation is given by that the virus attacks organisms that did not meet with virus until now. Therefore, there is a change in the clinical picture and more serious forms of the disease appear in the greater degree than before. Official statistics numbers of diseases in the EU in 2008-2012 published by the ECDC revealed that number of illnesses depends on the global climate changes and also on the climate in a current year. Data for year 2010 clearly reveal how big influence extreme temperatures have on the number of reported illnesses. With regard to prevention in the Czech Republic, as a main step was to designed the informing of tourists. The substantial part of the repressive measures against WNV disease is to stop transmission of WNV blood transfusions. This deals with in annex 3of Decree no. 143/2008 Coll.. Currently the draft of methodological instruction which sets out the procedure for assessing the risk of WNV infection and the procedure to reduce the risk of transmission of the virus through blood transfusions is in the comment procedure. By the survey of health facilities was found out that it is according the legislation, specifically Decree 233/2011 Coll.. Private microbiology and serology laboratories in Pilsen and Budweis do not test on positivity of WNV. Targeted surveillance of horse WNV in Czech Republic is doing from 2011. In 2011 2013 it was 4 5 WNV positive horses, in 2014 it was already 13 horses from a total of 783 horses tested positive WNV. Various geographic distribution of horses and high specific antibody titers according to veterinarians indicate increasing activity of the virus in the Czech Republic and the possible expansion of WNV into new areas. The thesis also analyzes three cases of WNV disease that have been imported to the Czech Republic from the USA, Tanzania and from Cyprus. In thesis is also described the first autochthonous case of WNV infection in the Czech Republic in 2013 which demonstrates the changing epidemiological situation in the country. Based on the obtained data is appreciable that the virus will be with regard to a changing climate and increased globalization spread to new areas in which will be probably cause diseases with serious clinical course. Whereas the virus has a tends to mutation it is expected also a gradual change of the clinical picture. To stop the spread of the virus should be carried out surveillance at all levels. Insomuch as is not in current time human vaccine available to curb the spread of the The essential elements od prevention includes informing tourists traveling to high-risk countries and countries potentially risky.

West Nile virus (WNV) is an emerging infectious disease that has widespread implications for public health practitioners across the world. Within a few years of its arrival in the United States the virus had spread across the North American continent. This research focuses on the development of a spatially explicit GIS-based predictive epidemiological model based on suitable environmental factors. We examined eleven commonly mapped environmental factors using both ordinary least squares regression (OLS) and geographically weighted regression (GWR). The GWR model was utilized to ascertain the impact of environmental factors on WNV risk patterns without the confounding effects of spatial non-stationarity that exist between place and health. It identifies the important underlying environmental factors related to suitable mosquito habitat conditions to make meaningful and spatially explicit predictions. Our model represents a multi-criteria decision analysis approach to create disease risk maps under data sparse situations. The best fitting model with an adjusted R2 of 0.71 revealed a strong association between WNV infection risk and a subset of environmental risk factors including road density, stream density, and land surface temperature. This research also postulates that understanding the underlying place characteristics and population composition for the occurrence of WNV infection is important for mitigating future outbreaks. While many spatial and aspatial models have attempted to predict the risk of WNV transmission, efforts to link these factors within a GIS framework are limited. One of the major challenges for such integration is the high dimensionality and large volumes typically associated with such models and data. This research uses a spatially explicit, multivariate geovisualization framework to integrate an environmental model of mosquito habitat with human risk factors derived from socio-economic and demographic variables. Our results show that such an integrated approach facilitates the exploratory analysis of complex data and supports reasoning about the underlying spatial processes that result in differential risks for WNV. This research provides different tools and techniques for predicting the WNV epidemic and provides more insights into targeting specific areas for controlling WNV outbreaks.