<p>No</p> / Dissertation

DeKalb and Fulton Counties, which share the metropolitan Atlanta area, have seen an increase in West Nile infected vector mosquitoes; the increase is associated with close proximity to combined sewer overflow facilities. Despite completion of the remediation system in 2008, the mosquito population testing positive for West Nile virus has increased each year from 2010 through 2012. Guided by the Geographical Information System framework and using spatial analysis and regression analyses, this study described and quantified the relationship between sewer system overflows and amplification of vector mosquitoes; an additional goal was to investigate their proximity to human cases of West Nile VIrus (WNV) infections. Comparing the prominence of all WNV vectors revealed how different mosquito species occupy the area. The Culex species was not detected in adult surveillance in 2012; however, the infection rate of mosquito pools increased by 15% and the human infection more than doubled. The influence of sewer system overflows became pronounced when this study analysis also identified that a proportion of West Nile-virus positive mosquito pools was significantly higher in approximately 58% of trap sites within 1 km of sewer overflow events and 30% over 1 km distance from sewer overflow events. Thus, the research contributes to shared information both in support of previous findings and considering novel sources that contribute to the proliferation of WNV. This research can help reduce the rate of WNV infection and decrease the resources needed to protect the public.

West Nile is an important novel virus in the United States, having spread rapidly since it was first detected in New York in 1999. The Centers for Disease Control and Prevention as well as many State Health Departments, have mandated programs for surveillance of West Nile Virus activity. These programs incorporate many different aspects including existing arboserology programs with additional testing for West Nile Virus and new plans that incorporate active and passive surveillance methods. The objective of this study was to examine all aspects of the Florida West Nile surveillance program to determine if there was transmission in the animal systems prior to human cases. The predictive analyses were done using regional data graphs, spatial information, correlations and regression models. Data for sentinel chickens, bird necropsy and mosquito pool surveillance from participating counties in Florida were obtained from the State of Florida surveillance database. The human data was obtained from the State of Florida reportable disease database for each county whether participating in the state surveillance programs or not. Clinical cases were examined by demographics (gender and age) and an incidence rate was calculated to demonstrate the effects of disease. Specific statistical methods used included Pearson's coefficient correlation, Poisson distribution regression modeling to show if any of the surveillance systems were predictors for human disease. The incidence rate analysis for clinical cases showed clustering of cases in adjacent counties within a region where Florida's panhandle and adjacent counties northeast had the highest incidence. Florida's central and southern regions had moderate human incidence. This provides useful information in transmission geography for prevention and control measures. Demographic analysis showed that there were twice as many males than females diagnosed with West Nile in Florida, this was true across the groups as well. The highest number of cases was seen within the age group over 55 years of age for West Nile Neuroinvasive Disease and for West Nile Fever the highest number of cases was within the 36-54 age range. The temporal distribution was determined using graphical representations of all of the surveillance types and clinical cases. In order to include all relevant data, the temporality was set from week 20 to week 52. This study found that all of the surveillance types (dead birds, mosquitoes and sentinels) offered a specialized strength for predicting clinical cases. However, mosquitoes proved to be the least efficient out of the three surveillance systems. The regional and spatial analysis showed that positive dead birds and sentinels provided the coverage for the surveillance systems in the state. However, Pearson's correlation coefficient was low for sentinel surveillance; this may be due to higher participation showing West Nile Virus activity in areas (especially rural) that have no reported human cases. This analysis did show that West Nile is detected in mosquito pool samples before it is detected in the dead bird or sentinel surveillance systems which provides an earlier warning for human cases. The Poisson distribution regression model was only useful for the pooled years and 2003. These showed that mosquitoes, positive dead birds and sentinels were good predictors for clinical cases for the combined years and dead birds and sentinels were significant for 2003 as well. The recommendations based on the results from this study would be to continue all the current surveillance efforts but with the following enhancements: 1. Increase the coverage and consistency of submissions for all surveillance types. 2. Set standard levels of participation for all counties based on the regional analyses and populations at risk. 3. Create standardized approaches for sampling, shipping and submitting samples (especially for mosquito pool submissions) and require that participating counties adhere to these standards. 4. Only submit specific birds known to be especially susceptible to West Nile Virus (e.g. corvids). 5. Targeted prevention and education strategies for higher risk groups based on their potential levels of exposure.

Within the state of Florida, there are three arboviruses of public health importance that can cause neuroinvasive disease in humans: West Nile Virus, Saint Louis Encephalitis Virus, and Eastern Equine Encephalitis Virus. Mosquitoes (Diptera: Culicidae) within the genus Culex are known and suspected vectors of these diseases. The vectors of these diseases can be present in urban wetland habitats that allow for exposure to residential communities. Vector ecology must be investigated in order to understand the dynamics of disease transmission. In Hillsborough County, Florida the spatial and temporal distribution of these vectors are not well established. An ecological study was conducted in the University of South Florida's Ecopreserve using trapping methodologies to sample the adult and gravid females as well as collect the egg population. Collections were made at three spatial points for the duration of July through December 2013 and compared to meteorological variables. Culex erraticus, a proposed bridge vector of Eastern Equine Encephalitis, was the most abundant adult species and gravid female captured. Culex nigripalpus, primary Floridian vector of Saint Louis Encephalitis and bridge vector of West Nile Virus, was the second most abundant adult species caught as well as the majority of eggs collected. Based on the results collected, the presence of Culex erraticus and Culex nigripalpus was confirmed. The majority of Culex erraticus adults were collected in September and October and Culex nigripalpus adults were the highest in July and August. The results of the gravid and egg collection generated crucial insight regarding methodology for studying vector ecology within this urban wetland habitat. However, modeling at spatial points based on meteorological variables yielded inconsistent results that illicit further investigation regarding these arboviral vectors of disease.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 76-86).

Two cellular innate responses, the dsRNA protein kinase (PKR) pathway and the 2'-5' oligoadenylate synthetase (OAS)/RNase L pathway, are activated by dsRNAs produced by viruses and reduce translation of host and viral mRNAs. PKR activation results in eIF2a phosphorylation. As a consequence of eIF2a phosphorylation, stress granules (SGs) are formed by the aggregation of stalled SG proteins with pre-initiation complexes and mRNA. West Nile virus (WNV) infections do not induce eIF2a phosphorylation despite upregulation of PKR mRNA and protein suggesting an active suppression of PKR activation. Assessment of the mechanism of suppression of PKR activation in WNV-infected cells indicated that WNV infections do not induce PKR phosphorylation so that active suppression is not required. In contrast to infections with "natural" strains of WNV, infections with the chimeric W956 infectious clone (IC) virus efficiently induce SGs in infected cells. After two serial passages, the IC virus generated a mutant (IC-P) that does not induce SGs efficiently but does induce the formation of NS3 granules that persist throughout the infection. This mutant was characterized. 2'-5' oligoadenylate synthetases (OAS) are activated by viral dsRNA to produce 2-5A oligos that activate RNase L to digest viral and cellular RNAs. Resistance to flavivirus-induced disease in mice is conferred by the full-length 2'-5' oligoadenylate synthetase 1b (Oas1b) protein. Oas1b is an inactive synthetase that is able to suppress the in vitro synthetase activity of the active synthetase Oas1a. The ability of Oas1b to inhibit Oas1a synthetase activity in vivo and to form a heteromeric complex with Oas1a was investigated. Oas1b suppressed 2-5A production in vivo. Oas1a and Oas1b overexpressed in mammalian cells co-immunoprecipitated indicating the formation of heteromeric complexes by these proteins. Unlike mice, humans encode a single OAS1 gene that generates alternatively spliced transcripts encoding different isoforms. Synthetase activity has previously been reported for only three of the isoforms. The in vitro synthetase activity of additional OAS1 isoforms was analyzed. All tested isoforms synthesized higher order 2-5A oligos. However, p44A only produced 2-5A dimers which inhibit RNase L.

The question of how to create communities where people altruistically care for, and look out for each other’s health and well-being is increasingly a central question in academic literature. However, altruism has long been belittled or ignored in the literature in terms of its ability to influence human behaviour. This tendency appears to have been carried over into the management of West Nile Virus (WNV), a sometimes serious disease that has spread throughout North America since first arriving in 1999. Specifically, government health educators have focused only on telling the public how what are referred to here as Community Protective Measures (CPMs) such as the elimination of standing water, can reduce personal risk or protect family members from the disease, rather than explaining how these measures can help protect others in their community as a whole. As a different approach to addressing this issue, this study sought to determine which communities and people (1) were undertaking CPMs out of an altruistic concern for others in their community, or (2) could be encouraged to engage in CPMs by making salient the benefits of these measures to the community. Study results came back positive, those that live in urban areas, and married or widowed people as opposed to singles or divorcees, those with children exhibiting significantly more concern for others about the disease. Additionally, women; married or widowed people; those who have younger children (0-18 years old); and those who had certain strong positive feelings about their community, namely knowing people better in the community, being involved in the community, and having a sense that people help each other in the community; were significantly more likely to already be willing to take action against the disease at least partly for the purposes of protecting the health of others. Additionally, albeit not significantly, a trend was noted in this regard with respect to those that rented and those who had children.. With regard to those who could be encouraged for altruistic reasons to undertake CPMs, such was found to be significantly the case for those not living in an Adult Lifestyle Communities (ALCs); those living in a city, town, or hamlet for a long (11-25 years) period of time; younger individuals (18 -35 years old), and singles or divorcees as opposed to married or widowed individuals. Although not found to be significant, a trend in this regard was found with respect to those that perceived themselves to live in a small- or medium-sized neighbourhoods, urban as opposed to suburban areas, females, renters, and those without children. A pilot study in a community with the characteristics where respondents were found to respond to learning about the community benefits of CPMs, as well as efforts to instill the characteristics of places where people already tend to be altruistically inclined, is recommended. The thesis concludes by discussing how relying upon, and encouraging altruistic tendencies could be applied to a variety of issues ranging from the control of other infectious diseases, to encouraging other health promoting behaviour such as the donation of organs, to addressing wider national as well as global matters like poverty or global climate change. By doing so, health and other planners could potentially take a more holistic, less rational, and advocacy approach to planning that seeks to build community capacity to deal with problems rather than reacting on a problem-by-problem basis.

The question of how to create communities where people altruistically care for, and look out for each other’s health and well-being is increasingly a central question in academic literature. However, altruism has long been belittled or ignored in the literature in terms of its ability to influence human behaviour. This tendency appears to have been carried over into the management of West Nile Virus (WNV), a sometimes serious disease that has spread throughout North America since first arriving in 1999. Specifically, government health educators have focused only on telling the public how what are referred to here as Community Protective Measures (CPMs) such as the elimination of standing water, can reduce personal risk or protect family members from the disease, rather than explaining how these measures can help protect others in their community as a whole. As a different approach to addressing this issue, this study sought to determine which communities and people (1) were undertaking CPMs out of an altruistic concern for others in their community, or (2) could be encouraged to engage in CPMs by making salient the benefits of these measures to the community. Study results came back positive, those that live in urban areas, and married or widowed people as opposed to singles or divorcees, those with children exhibiting significantly more concern for others about the disease. Additionally, women; married or widowed people; those who have younger children (0-18 years old); and those who had certain strong positive feelings about their community, namely knowing people better in the community, being involved in the community, and having a sense that people help each other in the community; were significantly more likely to already be willing to take action against the disease at least partly for the purposes of protecting the health of others. Additionally, albeit not significantly, a trend was noted in this regard with respect to those that rented and those who had children.. With regard to those who could be encouraged for altruistic reasons to undertake CPMs, such was found to be significantly the case for those not living in an Adult Lifestyle Communities (ALCs); those living in a city, town, or hamlet for a long (11-25 years) period of time; younger individuals (18 -35 years old), and singles or divorcees as opposed to married or widowed individuals. Although not found to be significant, a trend in this regard was found with respect to those that perceived themselves to live in a small- or medium-sized neighbourhoods, urban as opposed to suburban areas, females, renters, and those without children. A pilot study in a community with the characteristics where respondents were found to respond to learning about the community benefits of CPMs, as well as efforts to instill the characteristics of places where people already tend to be altruistically inclined, is recommended. The thesis concludes by discussing how relying upon, and encouraging altruistic tendencies could be applied to a variety of issues ranging from the control of other infectious diseases, to encouraging other health promoting behaviour such as the donation of organs, to addressing wider national as well as global matters like poverty or global climate change. By doing so, health and other planners could potentially take a more holistic, less rational, and advocacy approach to planning that seeks to build community capacity to deal with problems rather than reacting on a problem-by-problem basis.

Cellular T-cell intracellular antigen-1 related protein (TIAR) binds to the 3' terminal stem-loop of the West Nile virus minus-strand RNA [WNV 3'(-) SL RNA]. TIAR binding sites were previously mapped on loop 1 (L1) and loop 2 (L2) of the 3' (-) SL RNA and mutations of these sites in a WNV infectious clone inhibited virus replication. In the present study, data from in vitro binding assays suggested that multiple TIAR proteins bind to each WNV 3′ (-) SL RNA in a positively cooperative manner. The tertiary structure of WNV 3′ (-) SL RNA was predicted and it was suggested that L2 forms an exposed loop while L1 forms an embedded loop. We propose that TIAR binds first to L2 and that this interaction facilitates the binding of a second TIAR molecule to L1. Data from in vitro assays also showed that TIAR binds specifically to the WNV 3' (-) SL RNA but not to the complementary WNV 5' (+) SL RNA and that the C-terminal prion domain of TIAR contributes to RNA binding specificity. Immunoprecipitation experiments indicated that TIAR interacts with the WNV 3' (-) SL RNA in cells. Colocalization of TIAR and viral dsRNA in the perinuclear region of WNV-infected cells was visualized using a proximity ligation assay. In WNV-infected, TIAR-overexpressing cells, increased extracellular virus yields, intracellular viral protein and RNA levels, and an increased ratio of viral plus-strand RNA to minus-strand RNA were observed. These data suggest that TIAR enhances WNV plus-strand RNA synthesis from the minus-strand template. WNV infections induce small TIAR foci formation in primate cells but not rodent cells. The TIAR foci are located in the perinuclear region and differ in size and location from arsenite-induced stress granules (SGs). However, the small TIAR foci contain many SG components, such as G3BP, PABP, and eIF3A, but not HuR. Arsenite-induced SG formation is still inhibited by WNV infection in these cells. eIF2a phosphorylation was observed in some infected cells that contained WNV-induced TIAR foci but viral NS3 protein accumulation was not inhibited. The data suggest that WNV-induced TIAR foci in primate cells are not canonical SGs.

West Nile virus affected nearly 2,000 people in Texas in 2012, killing 89. Neither state and local public health institutions nor the medical community were well prepared for the unprecedented outbreak. The virus is carried by mosquitoes and can cause paralysis and other neurological damage. Other diseases carried by insect vectors, like dengue fever, are poised to resurge or emerge in Texas. Suspected effects of climate change, like warmer winters, may contribute to the prevalence of such diseases and frequency of outbreaks. Adequate surveillance of human cases of these diseases is crucial to the public health response, but is hampered by a low level of diagnosis and reporting throughout the state and spotty vector surveillance by local entities. / text