West Nile virus (WNV), a member of the genus Flavivirus transmitted by mosquitoes, first appeared in the New York in 1999. Within five years WNV was detected throughout the contiguous 48 states causing disease in reservoirs and accidental hosts alike. In Louisiana, WNV was first detected in 2001 with one human case, ten equine cases, and six dead birds reported. The introduction of WNV into Louisiana presented an unique opportunity to observe an emerging disease unfold, so a study was launched to gain insight into the epidemiology of WNV in Louisiana.
The first component, an environmental predictive model for West Nile virus, was developed using geographic information systems and remote sensing in relationship to the prevalence of human cases and the percent of WNV positive dead birds by parish for 2002 and 2003. Linear regression analysis showed a 13 variable model with environmental and human factors for the 2003 human dataset to be the best model. This model was able to explain 74% of the variation in human WNV prevalence by parish. The results of the model along with one-way chi-square analysis of categorical variables indicated largely urban cycle when the mosquito-bird transmission cycle reaches high levels as the main mode of WNV transmission with spillover to humans, and other accidental hosts.
A serosurvey of wild birds in East Baton Rouge Parish was conducted from November 2002 to October 2004. A total of 1287 samples were tested by the plaque reduction neutralization test. Overall, 222/1287 (17.25%; CI: 15.19-19.31) tested positive. Species, location, sex, age, and monthly differences were detected. The study identified Northern cardinals (Cardinalis cardninalis) as a statistically significant host for WNV in Louisiana.
Mediterranean house geckos (Hemidactylus turcicus) were assessed as a potential reservoir for West Nile virus. Geckos were inoculated orally with West Nile virus and a field study was conducted to determine the prevalence of WNV in naturally infected geckos. Results obtained through virus culture and RT-PCR indicated that geckos could become infected with an oral inoculation of WNV, but that naturally infected geckos do not produce high enough viremias to act as a reservoir.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-11132006-190148 |
| Date | 16 November 2006 |
| Creators | Gruszynski, Karen Ruth |
| Contributors | Ray Ferrell, John B Malone, Alma Roy, Mark A Mitchell, Lane Foil |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-11132006-190148/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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