| Climatic and landscape correlates for potential West Nile virus mosquito vectors in the Seattle region | Pecoraro, Heidi L. | 2007 |
KeywordsWNV AbstractClimatic and landscape patterns have been associated with both relative mosquito abundance and transmission of mosquito-borne illnesses in many parts of the world, especially warm and tropical climes. To determine if temperature, precipitation, or degree of urbanization were similarly important in the number of potential mosquito vectors for West Nile virus in the moderately temperate climate of western Washington, mosquitoes were collected using CDC carbon-dioxide/light traps set throughout the Seattle region during the summers of 2003 and 2004. The type and abundance of recovered species were compared to ecological correlates. Temperature and mosquito abundance were positively correlated, while precipitation was not strongly correlated with numbers of mosquitoes. Potential WNV mosquito vectors were most abundant in urban and suburban sites, including sites near communal roosts of American crows (Corvus brachyrhynchos). Exurban sites had the greatest vector species diversity, and Culex pipiens was the most abundant species throughout the region. AuthorsPecoraro, Heidi L., Day, Heather L., Reineke, Robert, Stevens, Nathan, Withey, John C., Marzluff, John M. and Meschke, J. Scott Year Published2007 PublicationJournal of Vector Ecology LocationsDOI10.3376/1081-1710(2007)32[22:CALCFP]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/17633422 |
| Comparative Analysis of Distribution and Abundance of West Nile and Eastern Equine Encephalomyelitis Virus Vectors in Suffolk County, New York, Using Human Population Density and Land Use/Cover Data | Rochlin, I. | 2008 |
Keywordsmosquito vectors, urban, rural, GIS, West Nile virus, WNV AbstractFive years of CDC light trap data from Suffolk County, NY, were analyzed to compare the applicability of human population density (HPD) and land use/cover (LUC) classification systems to describe mosquito abundance and to determine whether certain mosquito species of medical importance tend to be more common in urban (defined by HPD) or residential (defined by LUC) areas. Eleven study sites were categorized as urban or rural using U.S. Census Bureau data and by LUC types using geographic information systems (GISs). Abundance and percent composition of nine mosquito taxa, all known or potential vectors of arboviruses, were analyzed to determine spatial patterns. By HPD definitions, three mosquito species, Aedes canadensis (Theobald), Coquillettidia perturbans (Walker), and Culiseta melanura (Coquillett), differed significantly between habitat types, with higher abundance and percent composition in rural areas. Abundance and percent composition of these three species also increased with freshwater wetland, natural vegetation areas, or a combination when using LUC definitions. Additionally, two species, Ae. canadensis and Cs. melanura, were negatively affected by increased residential area. One species, Aedes vexans (Meigen), had higher percent composition in urban areas. Two medically important taxa, Culex spp. and Aedes triseriatus (Say), were proportionally more prevalent in residential areas by LUC classification, as was Aedes trivittatus (Coquillett). Although HPD classification was readily available and had some predictive value, LUC classification resulted in higher spatial resolution and better ability to develop location specific predictive models. AuthorsRochlin, I., Harding, K., Ginsberg, H. S. and Campbell, S. R. Year Published2008 PublicationJournal of Medical Entomology LocationsDOI10.1603/0022-2585(2008)45[563:CAODAA]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/18533453 |
| Comparison of Enzootic Risk Measures for Predicting West Nile Disease, Los Angeles, California, USA, 2004–2010 | Kwan, Jennifer L. | 2012 |
KeywordsWNV AbstractIn Los Angeles, California, USA, 2 epidemics of West Nile virus (WNV) disease have occurred since WNV was recognized in 2003. To assess which measure of risk was most predictive of human cases, we compared 3 measures: the California Mosquito-Borne Virus Surveillance and Response Plan Assessment, the vector index, and the Dynamic Continuous-Area Space-Time system. A case– crossover study was performed by using symptom onset dates from 384 persons with WNV infection to determine their relative environmental exposure to high-risk conditions as measured by each method. Receiver-operating characteristic plots determined thresholds for each model, and the area under the curve was used to compare methods. We found that the best risk assessment model for human WNV cases included surveillance data from avian, mosquito, and climate sources. AuthorsKwan, Jennifer L., Park, Bborie K., Carpenter, Tim E., Ngo, Van, Civen, Rachel and Reisen, William K. Year Published2012 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1808.111558 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/22840314 |
| COMPARISON OF MOSQUITO TRAPPING METHOD EFFICACY FOR WEST NILE VIRUS SURVEILLANCE IN NEW MEXICO | DiMenna, Mark A. | 2006 |
KeywordsMosquitoes, trapping methods, New Mexico, Rio Grande, West Nile virus, WNV AbstractAs part of the West Nile virus surveillance program for the state of New Mexico, 13 sites along the Rio Grande River were sampled for mosquitoes during spring and summer 2003. We evaluated 3 different trapping procedures for their effectiveness at capturing selected species of mosquitoes. The 3 methods used were a dry ice-baited Centers for Disease Control and Prevention (CDC) light trap set 1.5 m above the ground (standard method), a CDC light trap suspended within the forest canopy, and a gravid trap set on the ground. Thirteen sites were sampled for 10 1-night periods biweekly from May through September. The relative numbers of captured Culex tarsalis, Cx. salinarius, Cx. quinquefasciatus, and Aedes vexans as well as the numbers of total recorded captures of all species were compared for each trapping method. Significant differences were observed for each species by location and by trapping method. Culex tarsalis was most commonly caught in canopy or standard CDC traps, especially in cottonwood bosque. Culex salinarius was found most frequently in association with marshy water, and was most often caught in gravid or standard light traps. Culex quinque-fasciatus was captured almost exclusively in gravid traps within urban areas. Aedes vexans was primarily sampled in standard CDC light traps and found most frequently in wooded areas near floodplains. With the exception of Cx. quinquefasciatus, no species was collected significantly more frequently in gravid or canopy traps than in the standard CDC light trap. Our findings do not support altering the methods currently used in New Mexico, namely, the use of 1.5-m CDC light traps and gravid traps. An increased use of gravid traps seems to be warranted in monitoring urban vector populations (specifically Cx. quinquefasciatus and Cx. salinarius) that may be involved in human transmission. AuthorsParmenter, Robert R., DiMenna, Mark A., Bueno, Rudy, Norris, Douglas E., Sheyka, Jeff M., Molina, Josephine L., LaBeau, Elisa M., Hatton, Elizabeth S. and Glass, Gregory E. Year Published2006 PublicationJournal of the American Mosquito Control Association Locations- Espanola, NM (35.991, -106.082)
- Bernalillo, NM (35.0178, -106.629)
- Los Lunas, NM (34.8062, -106.733)
- Belen, NM (34.6628, -106.776)
- Velarde, NM (36.1673, -105.968)
- San Acacia, NM (34.2553, -106.899)
- Santa Fe, NM (35.687, -105.938)
- Bosque del Apache Wilderness (Chupadera Unit), Socorro, NM (33.8381, -106.939)
- Arroyo Hondo, NM (36.5361, -105.67)
- Pilar, NM (36.2691, -105.782)
- Los Alamos, NM (35.8881, -106.307)
DOI10.2987/8756-971X(2006)22[246:COMTME]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/17019770 |
| Completeness of West Nile virus testing in patients with meningitis and encephalitis during an outbreak in Arizona, USA | WEBER, I. B. | 2012 |
KeywordsWNV AbstractAccurate data on West Nile virus (WNV) cases help guide public health education and control activities, and impact regional WNV blood product screening procedures. During an outbreak of WNV disease in Arizona, records from patients with meningitis or encephalitis were reviewed to determine the proportion tested for WNV. Of 60 patients identified with meningitis or encephalitis, 24 (40%) were tested for WNV. Only 12 (28%) of 43 patients aged <0·01). Patients with clinical signs of weakness or paralysis, elevated CSF protein, admitted to an inpatient facility, or discharged to a rehabilitation facility were also more likely to have WNV testing performed. The lack of testing in younger age groups and in those with less severe disease probably resulted in substantial underestimates of WNV neuroinvasive disease burden. AuthorsWEBER, I. B., LINDSEY, N. P., BUNKO-PATTERSON, A. M., BRIGGS, G., WADLEIGH, T. J., SYLVESTER, T. L., LEVY, C., KOMATSU, K. K., LEHMAN, J. A., FISCHER, M. and STAPLES, J. E. Year Published2012 PublicationEpidemiology and Infection LocationsDOI10.1017/S0950268811002494 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/22123531 |
| Crow Deaths Caused by West Nile Virus during Winter | Dawson, Jennifer R. | 2007 |
KeywordsWNV AbstractIn New York, an epizootic of American crow (Corvus brachyrhynchos) deaths from West Nile virus (WNV) infection occurred during winter 2004–2005, a cold season when mosquitoes are not active. Detection of WNV in feces collected at the roost suggests lateral transmission through contact or fecal contamination. AuthorsEidson, Millicent, Ebel, Gregory D., Kramer, Laura D., Dawson, Jennifer R., Stone, Ward B., Young, David S., Galinski, David S., Pensabene, Jason P. and Franke, Mary A. Year Published2007 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1312.070413 |
| Culex Population Dynamics and West Nile Virus Transmission in East-Central Illinois | Lampman, Richard | 2006 |
KeywordsDiptera, Culicidae, Culex pipiens, Culex restuans, West Nile virus, infection rate, crossover, WNV AbstractTemporal changes in the abundance Culex restuans and Culex pipiens were monitored in east-central Illinois for over a decade using infusion-baited oviposition traps. The 2 species typically exhibited a seasonal shift in relative abundance with a mean crossover date (when the proportion of egg rafts from both species is equal) of August 10 or 11, depending on leap year, with a 95% confidence interval of ±10.7 days. The date of crossover was linearly related to the date of last spring frost and occurred on average about 123 days after the last spring frost. Despite the predictability of crossover, the weekly pattern in the proportion of Cx. pipiens before and after crossover varied considerably, even between years with similar crossover dates. After West Nile virus became established in our area, we found that transmission based on Culex from gravid traps did not increase until Cx. pipiens abundance increased in oviposition traps. Infection rates peaked within the half-month period after crossover. The peak in Cx. pipiens abundance in oviposition traps during this 3-year period was between the 2nd half of August and the end of September. A higher magnitude of transmission in 2002 coincided with warmer temperatures during July and August and an extended period in which the 2 Culex species were in relatively equal abundance. AuthorsLampman, Richard, Krasavin, Nina, Novak, Robert, Slamecka, Michael and Kunkel, Kenneth Year Published2006 PublicationJournal of the American Mosquito Control Association LocationsDOI10.2987/8756-971X(2006)22[390:CPDAWN]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/17067036 |
| Decelerating Spread of West Nile Virus by Percolation in a Heterogeneous Urban Landscape | Magori, Krisztian | 2011 |
KeywordsWNV AbstractVector-borne diseases are emerging and re-emerging in urban environments throughout the world, presenting an increasing challenge to human health and a major obstacle to development. Currently, more than half of the global population is concentrated in urban environments, which are highly heterogeneous in the extent, degree, and distribution of environmental modifications. Because the prevalence of vector-borne pathogens is so closely coupled to the ecologies of vector and host species, this heterogeneity has the potential to significantly alter the dynamical systems through which pathogens propagate, and also thereby affect the epidemiological patterns of disease at multiple spatial scales. One such pattern is the speed of spread. Whereas standard models hold that pathogens spread as waves with constant or increasing speed, we hypothesized that heterogeneity in urban environments would cause decelerating travelling waves in incipient epidemics. To test this hypothesis, we analysed data on the spread of West Nile virus (WNV) in New York City (NYC), the 1999 epicentre of the North American pandemic, during annual epizootics from 2000-2008. These data show evidence of deceleration in all years studied, consistent with our hypothesis. To further explain these patterns, we developed a spatial model for vector-borne disease transmission in a heterogeneous environment. An emergent property of this model is that deceleration occurs only in the vicinity of a critical point. Geostatistical analysis suggests that NYC may be on the edge of this criticality. Together, these analyses provide the first evidence for the endogenous generation of decelerating travelling waves in an emerging infectious disease. Since the reported deceleration results from the heterogeneity of the environment through which the pathogen percolates, our findings suggest that targeting control at key sites could efficiently prevent pathogen spread to remote susceptible areas or even halt epidemics. AuthorsMagori, Krisztian, Bajwa, Waheed I., Bowden, Sarah and Drake, John M. Year Published2011 PublicationPLoS Computational Biology LocationsDOI10.1371/journal.pcbi.1002104 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/21829332 |
| Delinquent Mortgages, Neglected Swimming Pools, and West Nile Virus, California | Reisen, William K. | 2008 |
KeywordsWNV AbstractAdjustable rate mortgages and the downturn in the California housing market caused a 300% increase in notices of delinquency in Bakersfield, Kern County. This led to large numbers of neglected swimming pools, which were associated with a 276% increase in the number of human West Nile virus cases during the summer of 2007. AuthorsReisen, William K., Takahashi, Richard M., Carroll, Brian D. and Quiring, Rob Year Published2008 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1411.080719 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/18976560 |
| DEMOGRAPHIC AND SPATIAL ANALYSIS OF WEST NILE VIRUS AND ST. LOUIS ENCEPHALITIS IN HOUSTON, TEXAS | RIOS, JANELLE | 2006 |
KeywordsWest Nile virus, St. Louis encephalitis, geospatial analysis, environment, demographics, WNV AbstractThis descriptive prevalence study describes the relationships between mosquito density and the presence of arboviruses (in mosquitoes and humans) with various socioeconomic and environmental factors present near the time of the arbovirus outbreak in Harris County, Texas, in 2002. This study suggests that mosquito density increased if the trap was located in an area with a large number of containers that may inadvertently retain rainwater (P = 0.056). When considering only virus-positive mosquitoes, significant relationships were observed if the trap was located near waste materials (P < 0.001) or near containers that may inadvertently retain rainwater (P = 0.037). Furthermore, the presence of arbovirus activity (in mosquitoes or humans) in a geographic area tended to be associated with the socioeconomic status of the local community. Although the results of the socioeconomic comparisons were not significant, they were suggestive, demonstrating an interesting trend. Compared with communities where virus activity was not observed, the socioeconomic status of the arbovirus-positive community was consistently lower. Specifically, results showed that the populations residing in virus-positive census tracts attained less education, earned less income per household, and were more likely to be below the poverty level. In addition, this study found that virus-positive mosquitoes were randomly distributed throughout the study area, whereas severe human infection cases were clustered. Based on the results of this study, we conclude that the health outcome of a local community as it relates to West Nile virus and St. Louis encephalitis is dependent on many factors, including the socioeconomic and environmental characteristics of the community. AuthorsRIOS, JANELLE, HACKER, CARL S., HAILEY, CHRISTINA A. and PARSONS, RAY E. Year Published2006 PublicationJournal of the American Mosquito Control Association LocationsDOI10.2987/8756-971X(2006)22[254:DASAOW]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/17019771 |
