west nile virus activity--united states, july 28-august 3, 2004.during july 28-august 3, a total of 141 cases of human west nile virus (wnv) illness were reported from 11 states (alabama, arizona, california, colorado, florida, illinois, nevada, new york, north dakota, south dakota, and texas). during 2004, a total of 20 states have reported a total of 406 cases of human wnv illness to cdc through arbonet. of these, 247 (61%) were reported from arizona. a total of 226 (57%) of the 406 cases occurred in males; the median age of patients was 51 years (range: 1 ...200415295314
west nile virus activity--united states, september 8-14, 2004.during september 8-14, a total of 195 cases of human west nile virus (wnv) illness were reported from 26 states (alabama, arizona, arkansas, california, colorado, florida, georgia, idaho, illinois, iowa, kansas, maryland, minnesota, missouri, nebraska, nevada, new mexico, new york, north dakota, oklahoma, oregon, pennsylvania, south dakota, tennessee, texas, and wisconsin).200415371969
west nile virus activity--united states, september 15-21, 2004.during september 15-21, a total of 218 cases of human west nile virus (wnv) illness were reported from 21 states (arizona, california, florida, illinois, indiana, kansas, maryland, michigan, minnesota, mississippi, missouri, nebraska, nevada, new mexico, north dakota, oklahoma, south dakota, texas, utah, wisconsin, and wyoming).200415385920
west nile virus activity--united states, october 6-12, 2004.during october 6-12, a total of 86 cases of human west nile virus (wnv) illness were reported from 18 states (arizona, florida, illinois, kansas, louisiana, michigan, minnesota, missouri, nevada, new jersey, new mexico, north dakota, ohio, oklahoma, pennsylvania, tennessee, texas, and utah).200415483530
west nile virus in host-seeking mosquitoes within a residential neighborhood in grand forks, north dakota.west nile virus (wnv) was first recovered in north dakota near the city of grand forks in june 2002. during 2002, 2003, and 2004, we collected mosquitoes from grand forks using mosquito magnet traps and tested them for wnv. the seasonal abundance, species composition, and reproductive status of female mosquitoes were correlated with local environmental temperature and state surveillance data on wnv to determine the factors affecting local transmission of wnv. over 90% of the mosquitoes collected ...200516417433
environmental and ecological determinants of west nile virus occurrence in horses in north dakota, 2002.west nile virus (wnv) outbreak in north dakota in 2002 included over 569 horse cases, clustered mainly in the eastern and northeastern parts of the state. the pattern of occurrence observed suggested existence of specific environmental and ecological factors that increased the risk for infection and illness in those locations. we developed a predictive model with factors that explained the pattern of wnv occurrence observed. results indicated that surface elevation, temperature, precipitation, r ...200716753077
west nile virus activity--united states, january 1-august 15, 2006.this report summarizes west nile virus (wnv) surveillance data reported to cdc through arbonet as of 3 a.m. mountain daylight time, august 15, 2006. a total of 26 states had reported 388 cases of human wnv illness to cdc. a total of 214 (56%) cases for which such data were available occurred in males; median age of patients was 49 years (range: 2-91 years). dates of illness onset ranged from january 6 to august 10; a total of 13 cases were fatal. a total of 68 presumptive west nile viremic blood ...200616915222
the economic impact of west nile virus infection in horses in the north dakota equine industry in 2002.this study estimated economic impacts associated with the west nile virus (wnv) outbreak in horses for north dakota in 2002. the 2002 epidemic in the united states was the largest meningoencephalitis epidemic reported in the western hemisphere. over 15,257 horse cases were reported in 43 states with most cases occurring in central united states. north dakota reported over 569 horse cases, with a mortality rate of 22%. the total costs incurred by the state were approximately us$1.9 million. the c ...200818551781
spatio-temporal cluster analysis of county-based human west nile virus incidence in the continental united states.west nile virus (wnv) is a vector-borne illness that can severely affect human health. after introduction on the east coast in 1999, the virus quickly spread and became established across the continental united states. however, there have been significant variations in levels of human wnv incidence spatially and temporally. in order to quantify these variations, we used kulldorff's spatial scan statistic and anselin's local moran's i statistic to uncover spatial clustering of human wnv incidence ...200919594928
theoretical potential of passerine filariasis to enhance the enzootic transmission of west nile virus.vertebrate reservoirs of arboviruses are often infected with microfilariae (mf). laboratory studies have shown that mf can enhance the infectivity of arboviruses to mosquitoes. soon after being ingested, mf penetrate the mosquito midgut. if the host blood also contains virus (i.e., vertebrate is dually infected), penetrating mf may introduce virus into the hemocoel. this can transform otherwise virus-incompetent mosquito species into virus-competent species and simultaneously accelerate viral de ...201223270173
evolutionary dynamics of west nile virus in the united states, 1999-2011: phylogeny, selection pressure and evolutionary time-scale analysis.west nile virus (wnv), an arbovirus maintained in a bird-mosquito enzootic cycle, can infect other vertebrates including humans. wnv was first reported in the us in 1999 where, to date, three genotypes belonging to wnv lineage i have been described (ny99, wn02, sw/wn03). we report here the wnv sequences obtained from two birds, one mosquito, and 29 selected human samples acquired during the us epidemics from 2006-2011 and our examination of the evolutionary dynamics in the open-reading frame of ...201323738027
arboviruses in north dakota, investigate arbovirus transmission in north dakota, we collected and screened mosquitoes for viral infection by vero cell culture assay. seven viruses were isolated from 13 mosquito species. spatial and temporal distributions of the important vectors of west nile virus (wnv), cache valley virus, jamestown canyon virus (jcv), and trivittatus virus are reported. snowshoe hare virus, potosi virus, and western equine encephalomyelitis virus were also isolated. the risks of culex tarsalis and aede ...201425487728
epidemiology of west nile virus in the highly epidemic state of north dakota, 2002-2007.west nile virus (wnv) continues to cause seasonal epidemics of neuroinvasive disease and febrile illness, which have been most dramatic in the central plains states. we studied the epidemiology of wnv disease in north dakota (nd), a highly epidemic state, six years following its first appearance in the state.201020297751
evaluation of an outbreak of west nile virus infection in horses: 569 cases (2002).to characterize an outbreak of west nile virus (wnv) infection in horses in north dakota in 2002, evaluate vaccine effectiveness, and determine horse characteristics and clinical signs associated with infection.200415515988
survey for west nile virus antibodies in wild ducks, 2004-06, usa.detection of west nile virus (wnv) in ducks has been reported in north america in isolated cases of mortality in wild waterbirds and following outbreaks in farmed ducks. although the virus has been noted as an apparent incidental finding in several species of ducks, little is known about the prevalence of exposure or the outcome of infection with wnv in wild ducks in north america. from 2004-06, we collected sera from 1,406 wild-caught american wigeon ( anas americana ), mallard ( anas platyrhyn ...201626981693
west nile virus infections projected from blood donor screening data, united states, 2003.national blood donor screening for west nile virus (wnv) rna using minipool nucleic acid amplification testing (mp-nat) was implemented in the united states in july 2003. we compiled national nat yield data and performed wnv immunoglobulin m (igm) testing in 1 wnv-epidemic region (north dakota). state-specific mp-nat yield, antibody seroprevalence, and the average time rna is detectable by mp-nat were used to estimate incident infections in 2003. wnv donor screening yielded 944 confirmed viremic ...200616704775
wintering of neurotropic velogenic newcastle disease virus and west nile virus in double-crested cormorants (phalacrocorax auritus) from the florida keys.during november 2002, six double-crested cormorants (dccs; phalacrocorax auritus) were found moribund in big pine key, fl, exhibiting clinical signs indicative of neurologic disease. postmortem diagnostic evaluations were performed on two adult birds. virulent newcastle disease virus (ndv) was isolated from a cloacal swab from cormorant 1. west nile virus (wnv) was isolated from the brain and lung of cormorant 2. nucleotide sequence analysis of a portion of the fusion (f) protein gene of the ndv ...200516094838
west nile virus activity--united states, august 25-31, 2004.during august 25-31, a total of 210 cases of human west nile virus (wnv) illness were reported from 14 states (arizona, california, florida, illinois, indiana, kansas, maryland, minnesota, montana, nevada, new mexico, north dakota, oklahoma, and pennsylvania).200415343148
west nile virus activity--united states, august 4-10, 2004.during august 4-10, a total of 89 cases of human west nile virus (wnv) illness were reported from 14 states (alabama, arizona, california, florida, illinois, kentucky, louisiana, minnesota, mississippi, missouri, new mexico, north dakota, south dakota, and wyoming).200415306758
influence of climate change on productivity of american white pelicans, pelecanus the past decade, severe weather and west nile virus were major causes of chick mortality at american white pelican (pelecanus erythrorhynchos) colonies in the northern plains of north america. at one of these colonies, chase lake national wildlife refuge in north dakota, spring arrival by pelicans has advanced approximately 16 days over a period of 44 years (1965-2008). we examined phenology patterns of pelicans and timing of inclement weather through the 44-year period, and evaluated the con ...201424416165
west nile virus antibody prevalence in red-winged blackbirds (agelaius phoeniceus) from north dakota, usa (2003-2004).this study was designed to explore the role that red-winged blackbirds (agelaius phoeniceus) may have played in disseminating west nile virus (wnv) across the united states. using enzyme-linked immunosorbent assays designed to detect wnv antibodies in avian species we were able to determine the wnv antibody prevalence in a cohort of red-winged blackbirds in central north dakota in 2003 and 2004. the peak wnv antibody prevalence was 22.0% in august of 2003 and 18.3% in july of 2004. the results o ...200616989570
neuroinvasive disease and west nile virus infection, north dakota, usa, determine risk for west nile virus (wnv) neuroinvasive disease in north dakota, we tested plasma samples from blood donors for wnv igg and compared infection rates with reported wnv neuroinvasive disease incidence. we estimate that 1 in 244 wnv infections leads to neuroinvasive disease; risk is substantially increased among men and older persons.022469465
ecological niche of the 2003 west nile virus epidemic in the northern great plains of the united states.the incidence of west nile virus (wnv) has remained high in the northern great plains compared to the rest of the united states. however, the reasons for the sustained high risk of wnv transmission in this region have not been determined. to assess the environmental drivers of wnv in the northern great plains, we analyzed the county-level spatial pattern of human cases during the 2003 epidemic across a seven-state region.200819057643
west nile virus neuroinvasive disease incidence in the united states, the geographic range of reported human west nile virus (wnv) disease has expanded across the united states, seasonal transmission and outbreaks have persisted over several years in many areas of the country. west nile virus neuroinvasive disease (wnnd) case reports from 2002 to 2006 were reviewed to determine which areas of the country have the highest reported cumulative incidence and whether those areas have had consistently high annual incidence. during the 5-year period examined, 9632 cas ...200818237264
west nile virus epizootiology, central red river valley, north dakota and minnesota, 2002-2005.west nile virus (wnv) epizootiology was monitored from 2002 through 2005 in the area surrounding grand forks, north dakota. mosquitoes were tested for infection, and birds were surveyed for antibodies. in 2003, wnv was epidemic; in 2004, cool temperatures precluded wnv amplification; and in 2005, immunity in passerines decreased, but did not preclude, wnv amplification.200616965705
the 2003 west nile virus united states epidemic: the america's blood centers experience.a detailed assessment of west nile virus (wnv) yield is needed to evaluate the effectiveness of the wnv nucleic acid amplification technology (nat) screening implemented in 2003.200515819665
Displaying items 1 - 26 of 26