| molecular determinants of virulence of west nile virus in north america. | west nile virus (wnv) is a mosquito-borne flavivirus that until very recently had not been found in the americas. in 1999, there was an outbreak of west nile encephalitis in new york and surrounding areas, involving 62 human cases, including 7 fatalities. the virus has subsequently become established in the united states of america (u.s.) with 4156 human cases, including 284 deaths, in 2002. the wnv strains found in the u.s. are members of "lineage i", a genetic grouping that includes viruses fr ... | 2004 | 15119761 |
| genomic sequence and phylogenetic analysis of culex flavivirus, an insect-specific flavivirus, isolated from culex pipiens (diptera: culicidae) in iowa. | adult mosquitoes (diptera: culicidae) were collected in 2007 and tested for specific viruses, including west nile virus, as part of the ongoing arbovirus surveillance efforts in the state of iowa. a subset of these mosquitoes (6,061 individuals in 340 pools) was further tested by reverse transcription-polymerase chain reaction (rt-pcr) using flavivirus universal primers. of the 211 pools of culex pipiens (l.) tested, 50 were positive. one of 51 pools of culex tarsalis coquillet was also positive ... | 2009 | 19645300 |
| characterization of culex flavivirus (flaviviridae) strains isolated from mosquitoes in the united states and trinidad. | recent reports indicate that flaviviruses similar to the cell fusing agent virus (cfav) naturally infect a wide variety of mosquito species. these newly recognized insect-specific viruses comprise a distinct cfav complex within the genus flavivirus. here, we describe the isolation and characterization of nine strains of culex flavivirus (cx fv), a member of the cfav complex, from mosquitoes collected in the united states (east texas) and trinidad. phylogenetic analyses of the envelope protein ge ... | 2009 | 19193389 |
| serologic evidence of west nile virus exposure in north american mesopredators. | sera from 936 mammalian mesopredators (virginia opossums, gray foxes, striped skunks, hooded skunks, raccoons, a bobcat, and a red fox) were collected during 2003 and 2004 in california, arizona, texas, louisiana, ohio, and wyoming and screened for flavivirus-specific antibodies by an epitope-blocking enzyme-linked immunosorbent assay (blocking elisa). serum samples positive for antibodies against flaviviruses were screened for west nile virus (wnv)-specific antibodies by blocking elisa and sele ... | 2007 | 17255248 |
| temporal and spatial alterations in mutant swarm size of st. louis encephalitis virus in mosquito hosts. | st. louis encephalitis virus (slev; flaviviridae; flavivirus) is a member of the japanese encephalitis serocomplex and a close relative of west nile virus (wnv). although slev remains endemic to the us, both levels of activity and geographical dispersal are relatively constrained when compared to the widespread distribution of wnv. in recent years, wnv appears to have displaced slev in california, yet both viruses currently coexist in texas and several other states. it has become clear that vira ... | 2011 | 21215334 |
| multiple genotypes of st. louis encephalitis virus (flaviviridae: flavivirus) circulate in harris county, texas. | st. louis encephalitis (sle) is endemic in harris county, texas. the disease is a public health concern in houston, the largest city in harris county, and in the state. consequently, intensive surveillance for sle virus in local mosquito populations is carried out by the harris county mosquito control division each year. in this study, we examined genetic variation among sle isolates obtained during routine virus surveillance over a 13-year time period (1986-1999). st. louis encephalitis virus i ... | 2001 | 11425155 |
| dengue hemorrhagic fever--u.s.-mexico border, 2005. | dengue fever is a mosquito-transmitted disease caused by any of four closely related virus serotypes (den-1, den-2, den-3, and den-4) of the genus flavivirus. infection with one of these serotypes provides lifelong immunity to the infecting serotype only. therefore, persons can acquire a second dengue infection from a different serotype, and second infections place them at greater risk for dengue hemorrhagic fever (dhf), the more severe form of the disease. dhf is characterized by bleeding manif ... | 2007 | 17687243 |