| persistent west nile virus transmission and the apparent displacement st. louis encephalitis virus in southeastern california, 2003-2006. | west nile virus (family flaviviridae, genus flavivirus, wnv) invaded the colorado desert biome of southern california during summer 2003 and seemed to displace previously endemic st. louis encephalitis virus (family flaviviridae, genus flavivirus, slev, an antigenically similar flavivirus in the japanese encephalitis virus serocomplex). western equine encephalomyelitis virus (family togaviridae, genus alphavirus, weev), an antigenically distinct alphavirus, was detected during 2005 and 2006, ind ... | 2008 | 18533445 |
| vector-host interactions of culex pipiens complex in northeastern and southwestern usa. | studies on the vector-host interactions of culex pipiens complex mosquitoes by sequencing portions of mitochondrial cytochrome b gene indicate that cx. p. pipiens f. pipiens predominantly feed on avian hosts (93.1%), and focus feeding activity on several key bird species, in particular the american robin, the gray catbird, and the house sparrow in connecticut. however, cx. p. quinquefasciatus indiscriminately feed on both birds and mammals. culex p. quinquefasciatus in harris county - texas and ... | 2012 | 23401953 |
| characterization of avian poxvirus in anna's hummingbird (calypte anna) in california, usa. | avian poxvirus (genus avipoxvirus, family poxviridae) is an enveloped double-stranded dna virus that may be transmitted to birds by arthropod vectors or mucosal membrane contact with infectious particles. we characterized the infection in anna's hummingbird (calypte anna; n = 5 birds, n = 9 lesions) by conducting diagnostic tests on skin lesions that were visually similar to avian poxvirus lesions in other bird species. skin lesions were single or multiple, dry and firm, pink to yellow, with sca ... | 2013 | 24502725 |
| host (avian) biting preference of southern california culex mosquitoes (diptera: culicidae). | the host preference of a vector mosquito species plays a significant role in determining human and animal risk of infection with mosquito-transmitted pathogens. host preferences of common southern california culex species for four bird species, american crow (corvus brachyrhynchos), house sparrow (passer domesticus), house finch (carpodacus mexicanus), and mourning dove (zenaida macroura), were examined by determining the proportion of each mosquito species that successfully engorged on each of ... | 2012 | 22679878 |
| surveys for antibodies against mosquitoborne encephalitis viruses in california birds, 1996-2013. | from 1996 through 2013, 54,546 individual birds comprising 152 species and 7 orders were banded, bled, and released at four study areas within california, from which 28,388 additional serum samples were collected at one or more recapture encounters. of these, 142, 99, and 1929 birds from 41 species were positive for neutralizing antibodies against western equine encephalomyelitis virus (weev), st. louis encephalitis virus (slev), or west nile virus (wnv) at initial capture or recapture, respecti ... | 2016 | 26974395 |
| blood-feeding patterns of the culex pipiens complex in sacramento and yolo counties, california. | mosquitoes in the culex pipiens complex are competent vectors of west nile virus (wnv; family flaviviridae, genus flavivirus) in the laboratory, and field-collected mosquitoes have tested positive for the virus in california and elsewhere. a better understanding of cx. pipiens complex blood-feeding patterns will help define the threat that these mosquitoes pose to human health and their role in wnv amplification in northern california. we collected blood-engorged cx. pipiens complex mosquitoes f ... | 2011 | 21485380 |
| repeated west nile virus epidemic transmission in kern county, california, 2004-2007. | west nile virus (wnv) has remained epidemic in kern county, ca, since its introduction in 2004 through 2007 when the human case annual incidence increased from 6-8 to 17 per 100,000, respectively. the 2007 increase in human infection was associated with contradicting surveillance indicators, including severe drought, warm spring but cool summer temperature anomalies, decreased rural and urban mosquito abundance but increased early season infection in urban culex quinquefasciatus say, moderate av ... | 2009 | 19198528 |
| overwintering of west nile virus in southern california. | west nile virus (family flaviviridae, genus flavivirus, wnv) invaded southern california during 2003, successfully overwintered, amplified to epidemic levels, and then dispersed to every county in the state. although surveillance programs successfully tracked and measured these events, mechanisms that allowed the efficient overwintering and subsequent amplification of wnv have not been elucidated. our current research provided evidence for three mechanisms whereby wnv may have persisted in south ... | 2006 | 16619621 |
| encephalitis virus persistence in california birds: experimental infections in mourning doves (zenaidura macroura). | after-hatching and hatching year, mourning doves were infected by inoculation with either western equine encephalomyelitis (wee) or st. louis encephalitis (sle) viruses; some birds in each group also were treated with the immunosuppressant cyclophosphamide before and during infection. cyclophosphamide treatment significantly increased the wee viremia but did not alterthe antibody response. in contrast, cyclophosphamide-treated and -untreated doves did not develop a detectable sle viremia but bec ... | 2004 | 15185951 |
| experimental infection of california birds with western equine encephalomyelitis and st. louis encephalitis viruses. | a total of 27 bird species from the san joaquin and coachella valleys of california were inoculated subcutaneously with sympatric strains of western equine encephalomyelitis (wee) and st. louis encephalitis (sle) viruses. overall, 133 of 164 birds inoculated with wee virus developed a viremia detected by plaque assay; significantly greater than 72 of 163 birds inoculated with sle virus. host competence was calculated as the average number of days that each avian species had a viremia > or = 2 lo ... | 2003 | 14765678 |
| patterns of avian seroprevalence to western equine encephalomyelitis and saint louis encephalitis viruses in california, usa. | temporal and spatial changes in the enzootic activity of western equine encephalomyelitis (wee) and st. louis encephalitis (sle) viruses were monitored at representative wetland study sites in the coachella, san joaquin, and sacramento valleys of california from 1996 to 1998 using three methods: (1) virus isolation from pools of 50 host-seeking culex tarsalis coquillett females, (2) seroconversions in flocks of 10 sentinel chickens, and (3) seroprevalence in wild birds collected by mist nets and ... | 2000 | 10916291 |
| the role of indigenous wild, semidomestic, and exotic birds in the epizootiology of velogenic viscerotropic newcastle disease in southern california, 1972-1973. | during an epornitic of velogenic viscerotropic newcastle disease (vvnd) in southern california, free-flying wild birds, captive and free-ranging semidomestic birds, and exotic birds were collected from the quarantine area to determine their role in the epizootiology of the disease. the vvnd virus was isolated from 0.04% of 9,446 free-flying wild birds, 0.76% of 4,367 semidomestic birds, and 1.01% of 3,780 exotic birds examined. three house sparrows and 1 crow directly associated with infected po ... | 1975 | 1176357 |