Thesis (M.Sc.)--York University, 2007. Graduate Programme in Mathematics and Statistics. / Typescript. Includes bibliographical references. Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR29300

Source: Masters Abstracts International, Volume: 47-06, page: 3501. Adviser: Kristy O. Murray. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 98-108). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 98-108). Also available on the Internet.

Thesis (M.S.) -- University of Tennessee, Knoxville, 2005. / Title from title page screen (viewed on July 13, 2005). Thesis advisor: Reid R. Gerhardt. Document formatted into pages (xii, 77 p. : ill. (some col.), maps (some col.)). Vita. Includes bibliographical references (p. 67-76).

Objective: The purpose of this investigation was to describe the long-term effects and functional outcomes of patients in Virginia who were reported to the Virginia Department of Health with West Nile virus (WNV) non-neuroinvasive and neuroinvasive disease. The study identified the duration of symptoms after initial illness, the number of persons who fully recovered versus the number who continue to be symptomatic and how patients' quality of life differed after illness.Methods: The study population was drawn from 60 human cases that met the surveillance case definition for non-neuroinvasive and neuroinvasive WNV illness in Virginia between 2002-2004. Information was collected during personal interviews using a standard questionnaire. The questionnaire included questions on demographics, clinical signs and symptoms, existing medical conditions and the respondents' personal assessment of health. Statistical analysis were used to compare pre and post illness symptoms, respondents vs. non-respondents, and non-neuroinvasive respondents vs. neuroinvasive respondents. Results: Thirty-four patients were enrolled in the study. Five (14.7%) respondents had non-neuroinvasive disease and 29 (85.2%) had neuroinvasive disease. Thirty respondents (88.2%) reported being hospitalized. Respondents with non-neuroinvasive disease spent a median of 3.5 (range, 0-7) days in the hospital and were unable to resume normal activities for a median of 17 (range, 7-365) days. Respondents with neuroinvasive disease spent a median of 7.5 (range, 0-82) days in the hospital and were unable to resume normal activities for a median of 127.50 days (range, 0-1023). Two (40%) of the respondents that suffer from non-neuroinvasive illness were unable to resume normal activities for at least 90 days. Fifteen (51.7%) respondents with neuroinvasive disease were unable to resume normal activities for at least 90 days. At the time of the interview, 20% of respondents with non-neuroinvasive disease reported fatigue, tremors, arthralgia, paralysis and memory problems. Respondents with neuroinvasive disease reported fatigue (58.5%), weakness (51.7%), myalgias (37.9%), confusion (41.4%), and memory loss (55.2%). Conclusion: WNV illness, including non-neuroinvasive illness, may be more serious and prolonged than generally thought. Neuroinvasive disease resulted in long-term morbidity and non-neuroinvasive disease resulted in work absenteeism and extended recovery periods. The mortality rates and potential long-term effects associated with non-neuroinvasive and neuroinvasive illness emphasizes the importance of continuing to develop effective methods of targeting preventive education to high-risk populations while continuing to pursue longer-term solutions such as vaccines to prevent emerging infection. Further research is needed to document the long-term effects of WNV, especially in areas with a high number of WNV human cases with more non-neuroinvasive patients. WNV is an emerging infectious disease with a wide clinical spectrum and variable long-term effects; thus a public health concern.

A number of emerging vector-borne diseases have the potential to be transmitted in the UK by native mosquitoes. Human infection by some of these diseases requires the presence of communities of multiple vector mosquito species. Mitigating the risk posed by these diseases requires an understanding of the spatial distributions of the UK mosquito fauna. Little empirical data is available from which to determine the distributions of mosquito species in the UK. Identifying areas at risk from mosquito-borne disease therefore requires statistical modelling to investigate and predict mosquito distributions. This thesis investigates the distributions of potential vector mosquitoes in the UK at landscape to national scales. A number of new methodological approaches for species distri- bution modelling are developed. These methods are then used to map and understand the distributions of mosquito communities with the potential to transmit diseases to humans. Chapter 2 reports the establishment of substantial populations of the West Nile virus (WNV) vector mosquito Culex modestus in wetlands in southern England. This represents a drastic shift in the species’ known range and an increase in the risk of WNV transmission where Cx. modestus is present. Chapter 3 develops and applies a new species interaction distribution model which identifies fish and ditch shrimp of the genus Palaemonetes as predators which may restrict the distribution of the potential WNV vector community in these wetlands. Chapter 4 develops a number of methods to make robust predictions of the probability of presence of a species from presence-only data, by eliciting and applying estimates of the species’ prevalence. Chapter 5 introduces a new Bayesian species distribution modelling approach which outperforms existing methods and has number of useful features for dealing with poor- quality data. Chapter 6 applies methods developed in the previous two chapters to produce the first high-resolution distribution maps of potential vector mosquitoes in the UK. These maps identify several wetland areas where vector communities exist which could maintain WNV transmission in birds and transmit it to humans. This thesis makes significant contributions to our understanding of the distributions of UK mosquito species. It also provides methods for species distribution modelling which could be widely applied in ecology and epidemiology.

This thesis deals with infectious diseases transmitted by arthropods in the Czech Republic in period of 2002 - 2011. Meeting the objectives and answer the research questions, I managed using secondary analysis of reported cases infectious diseases transmitted by arthropods in the information system for reporting and recording of infectious diseases - EPIDAT and literature review and subsequent analysis of scientific articles. Important additional informations were provided by State Veterinary Institute in Prague and the National Reference Laboratory for arboviruses in Ostrava. Thesis does not deal with number of single values, but it is focused on epidemiological severity of analyzed cases, severity of clinical course and risk of introducing infection in the Czech Republic. Theoretical part of the thesis describes selected arboviruses infections. Tick-borne encephalitis is one of the most important diseases transmitted by arthropods in our surroundings. Number of reported cases of tick-borne encephalitis was quite constant in monitored period 2002 - 2011, according to my research and statistical verification. Highest morbidity was in 2006. The same year the highest incidence of disease Tick-borne encephalitic was reported in region of Vysočina. This number is far closer to number of reported cases in region of South Bohemia which was the most affected region thought the entire period. Prevention exists against tick-borne encephalitis. It is vaccination which is recommended for people staying in natural foci of infection in the Czech Republic and abroad. In the Czech republic becomes more important West Nile fever. Increased incidence of this disease is recorded in the USA, but also in many European countries (eg Greece, Hungary, Italy) in recent years. One of the goals of this thesis is to characterize the surveillance of West Nile fever in the Czech republic. Monitoring antibody titer against West Nile virus in the serum of horses is one of the basic elements of surveillance of this disease in our country. 5 samples of the blood serum was increased titers of antibodies to West Nile virus. Various geographic distribution of horses and high specific antibody titers indicate increasing activity of West Nile virus. Clinical disease of horses not being recorded in the Czech republic. In the field of human medicine have been reported three imported cases of West Nile fever. Other arboviruses infections, that appeared in our country, is dengue disease and viral disease Chikungunya. In the monitored period there were a total of 98 reported cases of imported disease. Most cases were imported from India. Three cases of Chikungunya disease were reported in 2006 in connection with a stay on the island of Mauritius, where was the epidemic at this time. People can travel freely and there is the risk of importing diseases from the tropics and subtropics. Some infections transmitted by arthropods are in areas where it was previously absent recently. Prevention is essential. Specific and non-specific prevention. Another important element of prevention is strict adherence to methods for surveillance of disease.Viral infections transmitted by arthropods are among the most important emergent infectious diseases. In addition to malaria, malnutrition and helminth infection are the largest public health problem, not only in third world countries.

Japanese encephalitis virus (JEV) and West Nile virus (WNV) are closely related Flaviviruses that are important arthropod-borne human pathogens. Both of these viruses can cause encephalitis with significant morbidity and mortality after infection. Flaviviruses co-circulate in many areas of the world, which raises the risk for sequential infection between heterologous viruses. Sequential infection between dengue virus serotypes can lead to cross-protection, but in some cases, it leads to a severe outcome, dengue hemorrhagic fever. Previous work in hamsters and non-human primates demonstrated that prior JEV immunity protects against a lethal WNV infection. However, the ability of prior WNV immunity to protect against a lethal JEV infection has been inconclusive. WNV-immune hamsters were fully protected from JEV viremia, but in non-human primates, prior WNV-immunity only reduced disease severity, with symptoms of encephalitis still observed. These differences in cross-protection led to further investigation on the directionality as well as the underlying mechanisms for this phenomenon. Previous work in our lab found that JEV-immune C57BL/6J (B6) mice were fully protected against a lethal WNV infection, and JEV-immune CD4+ and CD8+ T cells were required for this cross-protection. In other mouse models, memory cross-reactive CD4+ and CD8+ T cell responses may induce protection or immunopathology upon secondary heterologous viral challenge. We hypothesize that JEV/WNV cross-reactive CD4+and CD8+ T cells preferentially expand upon 2o infection and contribute to cross-protection. To elucidate the potential role of T cells in sequential flavivirus infection, we identified and characterized cross-reactive CD4+ and CD8+ T cell responses between JEV and WNV. A previously reported WNV NS4b CD8+ T cell epitope and its JEV variant elicited CD8+ T cell responses in both JEV- and WNV-infected mice. Despite similarities in viral burden for pathogenic JEV and WNV viruses, CD8+ T cells from pathogenic JEV-infected mice exhibited functional and phenotypic profiles similar to those seen for the attenuated JEV strain. We believe the differences in the CD8+ T cell responses during primary JEV and WNV infection are due at least in part to the low levels of peripheral replication seen in JEV-infected mice compared to WNV-infected mice. We also found that WNV-immune B6 mice were protected against a lethal JEV infection. Cross-reactive CD8+ T cells in JEV-immune mice rapidly expanded after WNV infection. Even though WNV-immune mice had higher frequencies of memory CD8+ T cells, cross-reactive CD8+ T cells did not expand after secondary JEV infection. Neutralizing antibodies to JEV were detected in WNV-immune mice; however, cross-reactive CD8+ T cells did not expand even in the absence of these cross-reactive neutralizing antibodies. We did not detect any differences in the CD8+ T cell repertoires between JEV- and WNV-infected mice nor were WNV-immune CD8+ T cells functionally exhausted. In fact, proliferation of memory CD8+ T cells did not correlate with the ability of WNV-immune CD8+ T cells to restrict recombinant vaccinia viruses expressing the cross-reactive epitope or lyse peptide-coated targets. These data suggest that the higher frequency of memory CD8+ T cells and cross-reactive antibodies in WNV-immune mice are better able to prevent neuroinvasion following 2o JEV infection.

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.