Publications

[post-epizootic activity of western equine encephalitis virus in argentina].	it is shown here the wee virus activity in argentina in 1983-1986 post-epizootic period. a surveillance system was established by the equine case notification and the sentinel animal method. among the thirteen equine focus notified between september 1983-september 1985 in córdoba and santa fe provinces, 5 presumptive cases out of 16 sick horses were confirmed by the hemagglutination inhibition test for wee epizootic virus. twenty eight notified human cases were studied with negative results. the ...	1993	8234736
western equine encephalomyelitis: virulence markers and their epidemiologic significance.	comparative studies are described on the virulence of the western equine encephalomyelitis (wee) complex viruses for mice. three epizootic wee virus strains (mcmillan, cba 87, and cba civ 180) and five enzootic wee complex viruses (highlands j [hj], y62-33, aura, fort morgan [fm], and wee ag80-646) were examined. the neurovirulence and the neuroinvasiveness of these viruses for adult mice were established and correlated with viremia and virus replication in brain tissue. adult mice inoculated in ...	1993	8103970
a comparison of the nucleotide sequences of eastern and western equine encephalomyelitis viruses with those of other alphaviruses and related rna viruses.	the complete nucleotide sequence of a 1982 florida strain of eastern equine encephalomyelitis (eee) virus, and partial sequence of the nonstructural protein genes of western equine encephalomyelitis (wee) virus, were determined. the eee virus genome was 11,678 nucleotides in length, excluding the cap nucleotide and poly(a) tail, and the nucleotide composition was 28% a, 24% g, 25% c, and 23% u. the organization of both eee and wee virus genomes was like that of other alphaviruses and included a ...	1993	8105605
arboviral disease--united states, 1991.	during 1991, state and local health departments reported 122 cases of human arboviral encephalitis to cdc. more than half (69) of the cases resulted from outbreaks of st. louis encephalitis (sle) in arkansas and texas. in addition, an epizootic of eastern equine encephalitis (eee) extending from the atlantic and gulf coasts into the upper midwest caused sporadic human cases and a substantial loss of livestock. this report summarizes the reported cases of arboviral encephalitis in the united stat ...	1992	1321947
from the centers for disease control. arboviral disease--united states, 1991.		1992	1324995
mosquito and arbovirus ecology in southeastern california, 1986-1990.	mosquito abundance and western equine encephalomyelitis (wee) and st. louis encephalitis (sle) virus activity were monitored in five valleys in southeastern california from june 1986 through april 1990 to study virus overwintering and possible dissemination from south to north along geographically defined corridors. culex tarsalis coquillett predominated in co2 trap collections and was the only species repeatedly infected with wee and sle viruses. abundance peaked during april-may and august-oct ...	1992	1352557
transmission of western equine encephalomyelitis virus by argentine aedes albifasciatus (diptera: culicidae).	aedes albifasciatus (macquart) has been considered a potential vector of western equine encephalitis (wee) virus in argentina because it has been found naturally infected, it is susceptible to infection per os, and its distribution and feeding habits are compatible with those of an epizootic and epidemic vector. ae. albifasciatus females collected in the vicinity of cordoba, argentina, were highly susceptible to wee virus perorally (id50 less than 0.5 vero cell plaque-forming units) when fed on ...	1992	1404265
pathologic changes in the midgut of culex tarsalis following infection with western equine encephalomyelitis virus.	midguts of two strains of the mosquito vector culex tarsalis were examined by light and electron microscopy following infection with western equine encephalomyelitis virus. infection of the highly susceptible knight's landing strain with high-titered blood meals resulted in pathologic changes in the midgut epithelium after 2-4 days of incubation; lesions included sloughing of epithelial cells into the lumen and necrosis of cells in situ. infection of knight's landing strain mosquitoes with low-t ...	1992	1449210
experimental inoculation of three arboviruses in black-bellied whistling ducks (dendrocygna autumnalis).	wild-caught, immature black-bellied whistling ducks (dendrocygna autumnalis) were inoculated with eastern equine encephalitis (eee), st. louis encephalitis (sle), or western equine encephalitis (wee) virus. susceptibility, duration and titer of viremia, and antibody response to these arboviruses were determined. birds from all inoculated groups became viremic. higher virus titers occurred in the eee group but overall mean titers were not significantly different among experimental groups. all bir ...	1992	1474647
evaluation of domestic pigeons as sentinels for detecting arbovirus activity in southern california.	flocks of sentinel domestic pigeons (columbia livia) detected increases in st. louis encephalitis (sle) and western equine encephalomyelitis (wee) virus activity in southern california concurrently with flocks of sentinel chickens. however, occasional low-titered, transient seroconversions to both wee and sle viruses also occurred in pigeons during periods when virus activity was not detected by seroconversions in sentinel chickens, by virus isolation from culex mosquitoes, or by human disease. ...	1992	1536386
arboviral encephalomyelitides of livestock in the western hemisphere.		1992	1601730
arboviral infections in the united states.	arboviruses are important considerations in the differential diagnosis of encephalitis and other acute infections. alterations in the environment and in human behaviors contribute to changing patterns of arboviral transmission. these trends, the periodic epidemic resurgence of arboviral diseases such as st. louis encephalitis, and the discovery of new arboviruses present a continued challenge to infectious disease clinicians.	1991	1646839
an assessment of the biological capacity of a sacramento valley population of aedes melanimon to vector arboviruses.	daily survivorship, duration of the gonotrophic cycle, absolute abundance and season-long relative abundance were estimated for aedes melanimon in the sacramento valley of california in 1987 and 1988 using mark-release-recapture (mrr) techniques and by monitoring changes in the abundance and parity rate of the native population. one objective of these studies was to determine the extent to which a. melanimon was biologically capable of serving as a horizontal arbovirus vector. daily survivorship ...	1991	2042703
multiple intracranial calcifications after western equine encephalitis.		1991	2067893
peroral susceptibility of aedes albifasciatus and culex pipiens complex mosquitoes (diptera: culicidae) from argentina to western equine encephalitis virus.	the transmission cycle of western equine encephalitis (wee) virus in south america is unknown. a wee virus strain was isolated from aedes albifasciatus in argentina during the wee epizootic of 1982-83. also, culex pipiens from argentina was reported to be able to transmit wee virus experimentally, but other results indicate that cx. pipiens from the usa is refractory to this virus. we determined the susceptibility of argentina strains of ae. albifasciatus and culex pipiens complex mosquitos to i ...	1990	2103643
complete sequence of the genomic rna of o'nyong-nyong virus and its use in the construction of alphavirus phylogenetic trees.	the alphaviruses are a group of about 25 positive-strand rna viruses that are important human and veterinary pathogens and that are geographically dispersed. we report here the complete nucleotide sequence of the genomic rna of the alphavirus, o'nyong-nyong virus. the rna is 11,835 nucleotides in length and the organization of the genome is typical of alphaviruses. phylogenetic trees were constructed from the protein sequences of o'nyong-nyong and six other alphaviruses. trees were constructed f ...	1990	2155505
temporal variations in the susceptibility of a semi-isolated population of culex tarsalis to peroral infection with western equine encephalomyelitis and st. louis encephalitis viruses.	a semi-isolated population of culex tarsalis in kern county, ca was found to vary significantly in its seasonal and yearly susceptibility to peroral infection with western equine encephalomyelitis (wee) and st. louis encephalitis (sle) viruses during the breeding seasons of 1975-1981. female cohorts of the population were significantly more resistant to wee virus from 1975 through 1977 than from 1978 through 1981. on the average, females were 40 times more susceptible to wee virus during may tha ...	1990	2160200
diel changes in adult mosquito microhabitat temperatures and their relationship to the extrinsic incubation of arboviruses in mosquitoes in kern county, california.	microhabitat temperatures experienced by nocturnally active culex tarsalis coquillett mosquitoes were measured in the southern san joaquin valley of california. temperatures of the diurnal resting shelter and nocturnal activity air space were measured by digital recorder at three cx. tarsalis habitats in kern county. temperatures measured by digital recorders agreed well with temperatures recorded concurrently at nearby california irrigation management and inspection system weather stations. mon ...	1990	2167374
persistence of mosquito-borne viruses in kern county, california, 1983-1988.	the persistence of arboviruses was studied from 1983 to 1988 in mixed agriculture, marsh, riparian, and foothill habitats in kern county, ca. western equine encephalomyelitis (wee) virus was isolated frequently during 1983 from culex tarsalis and aedes melanimon and was detected by the seroconversion of sentinel chickens. wee virus then disappeared, even though vector competence studies during 1984-1986 showed that cx. tarsalis was able to transmit wee virus. st. louis encephalitis (sle) virus w ...	1990	2240370
effect of the anesthetizing agent triethylamine on western equine encephalomyelitis and st. louis encephalitis viral titers in mosquitoes (diptera: culicidae).	triethylamine (tea) is a chemical compound that provides an effective means to anesthetize mosquitoes. the mosquitoes remain alive but are incapacitated for several hours; they do not recover following treatment. there was no effect on the titers of infectious virus recovered from western equine encephalomyelitis or st. louis encephalitis virus-infected culex tarsalis coquillett and aedes dorsalis (meigen) that were anesthetized with tea prior to storage at -70 degrees c. furthermore, tea had no ...	1990	2280383
binding of western equine encephalomyelitis virus to brush border fragments isolated from mesenteronal epithelial cells of mosquitoes.	brush border fragments (bbf) were isolated from mesenteronal epithelial cells of mosquitoes that are either susceptible (ws culex tarsalis) or refractory (wr cx. tarsalis; culex pipiens) to peroral infection by western equine encephalomyelitis (wee) virus. the isolated bbf were combined with radiolabeled wee virus in a binding assay to compare the amount of virus bound by bbf from susceptible and refractory mosquitoes. bbf and wee virus were mixed in a microcentrifuge tube, incubated for 1 h and ...	1990	2291333
[immune mechanisms of resistance in mice to the western equine encephalomyelitis virus].	using the immunogenetic method and method of immunomodification of outbred animals, it was established that immune response of humoral or cell-mediated type to wee virus antigens did not play any important role in the survival of intact mice infected with wee virus. under such conditions, it is inexpedient to select immune response modulators. the immune response of predominantly cell-mediated type is a determining factor of resistance to wee virus in mice after immunization started 7 days befor ...	1990	1964514
effects of house sparrow age and arbovirus infection on attraction of mosquitoes.	to test the hypothesis that arbovirus infection or advancing age increases the attractiveness of avian hosts to vector mosquitoes, we used an olfactometer that measures the response of mosquitoes to the passive, vertical diffusion of host-related cues. st. louis encephalitis or western equine encephalomyelitis virus infection in house sparrows (passer domesticus (l.], regardless of age, had no detectable effect on culex quinquefasciatus say or cx. tarsalis coquillett attraction, respectively, at ...	1990	1977913
antiviral activities of pyrimidine nucleoside analogues: some structure--activity relationships.	seventeen nucleoside derivatives (derived from arabinosylcytosine, resp. cytidine, 5-fluorouracil and uracil) were tested by agar-diffusion plaque-inhibition test for their antiviral activity with herpes simplex, vaccinia, fowl plague, newcastle disease and western equine encephalomyelitis viruses. the highest antiviral activity against dna viruses exhibited arabinosylcytosine, n4-acylarabinosylcytosines, arabinosylthiouracil, cyclocytidine and its 5'-chloroderivative. rna viruses were inhibited ...	1990	1981442
specificity of the murine t helper cell immune response to various alphaviruses.	we investigated the specificity of the t helper (th) cell immune response to three alphaviruses: venezuelan equine encephalomyelitis (vee), eastern equine encephalitis (eee) and western equine encephalitis (wee). single cell suspensions were prepared from spleens of virus-primed c3h mice, and t lymphocyte populations were enriched by nylon wool chromatography. t cells were incubated in vitro with irradiated, syngeneic splenic stimulator cells previously exposed to purified virus. cellular prolif ...	1989	2479713
the prevalence of antibodies against viruses causing kumlinge and pogosta diseases on the islands of iniö on the southwest coast of finland.	the prevalence of antibodies against viruses causing kumlinge (tick-borne encephalitis) and pogosta disease in the population of iniö, a small island community in southwest finland was measured. antibodies against kumlinge disease were found in 28% of the population, and increased from 10% in the 0-19 year age group to 42% in the 60-79 year age group. the prevalence varied markedly between different islands, being highest in the outer, bushy islands. antibodies against pogosta disease were detec ...	1989	2543059
cross-protective immunity between equine encephalomyelitis viruses in equids.	eighteen equids were inoculated with eastern equine encephalomyelitis (eee) and 18 equids with western equine encephalomyelitis (wee) viruses to produce eee virus- and wee virus-immunized equids. twelve surviving eee virus-seropositive equids, 15 surviving wee virus-seropositive equids, and 10 nonimmunized, seronegative equids (controls) were subsequently inoculated with an equine pathogenic (epizootic) strain of venezuelan equine encephalomyelitis (vee) virus to determine cross-protective immun ...	1989	2552875
[serologic study of arbovirus in 2 localities of the juventud island].	a serologic study is made in two population groups in the isle of youth. a total 268 blood samples in blotting paper are subjected to the hemagglutination inhibition technique, using the eastern equine encephalomyelitis, western equine encephalomyelitis, saint louis encephalitis, and dengue 2 viruses; 16% positivity to flavivirus was found. a second serum sample was taken in people positive by the hemagglutination inhibition technique in order to carry out the techniques of complement fixation a ...	1989	2561798
a case of western equine encephalitis--alberta.		1989	2611922
occurrence of culex erythrothorax in southeastern colorado and report of virus isolations from this and other mosquito species.	significant numbers of culex erythrothorax were collected during arbovirus surveillance in 1987 and 1988 at las animas, bent county, on the high plains of southeastern colorado. this finding extends the range of this species to the eastern side of the rocky mountains. the isolation of western equine encephalitis virus in 1988 from both cx. tarsalis and cx. erythrothorax suggests that the latter also may be involved in the endemic cycle of this virus in the area. st. louis encephalitis, hart park ...	1989	2614403
dot-elisa for serodiagnosis of human infections due to western equine encephalitis virus.	a standard dot-elisa (enzyme-linked immunosorbent assay) was modified for use in detecting igm and igg class antibodies to western equine encephalitis (wee) virus in serum samples from humans infected with this virus. nitrocellulose membranes were soaked in supernatant fluid from wee virus-infected cell cultures, air dried, and blocked with bovine protein. serum samples were pipetted onto sections of the nitrocellulose, incubated, and washed. addition of antibody to human immunoglobulin conjugat ...	1989	2621241
[phagocytosis system and resistance of mice to western equine encephalomyelitis virus].		1989	2633471
characterization of the mesenteronal infection with western equine encephalomyelitis virus in an incompetent strain of culex tarsalis.	interactions of western equine encephalomyelitis (wee) virus are compared with mesenterons of 2 genetically selected susceptible (ws) and refractory (wr) lines of culex tarsalis. both ws and wr females had similar susceptibility when parenterally inoculated with virus, thus it was initially thought that resistance in wr cx. tarsalis was associated with a mesenteronal infection barrier. present data on viral growth in mesenterons dissected from females fed on virus-soaked pledgets suggest that vi ...	1989	2774065
[interferon responses of various populations of lymphocytes of inbred mice with various degrees of sensitivity to the western equine encephalitis virus].	the sensitivity of mice of three lines: cba, balb/c, and c57bl/6 (males aged greater than or equal to 4-5 and one week) to peripheral inoculation with western equine encephalomyelitis (wee) virus was studied. the c57bl/6 line was found to be the most and cba the least sensitive. the first generation hybrids between these lines are intermediate in their sensitivity to wee virus. a correlation was established between the increased sensitivity to wee virus of c57bl/6 mice and the defect of the inte ...	1989	2786281
western equine encephalitis in avian populations in north dakota, 1975.	the involvement of wild birds in western equine encephalitis (wee) and st. louis encephalitis (sle) virus activity in the red river valley area of north dakota (usa) during a wee epidemic was investigated in august 1975. free-ranging birds were captured with mist nets and nestlings by hand. virologic and serologic results indicated that a similar rate of wee virus activity occurred throughout richland county and between permanent and summer resident birds. the rate of sle virus activity in the b ...	1989	2810548
encephalomyelitis vaccines: a vero-derived cell culture alternative to primary duck embryonic cell cultures.		1988	2833043
reevaluation of the western equine encephalitis antigenic complex of alphaviruses (family togaviridae) as determined by neutralization tests.	fourteen viruses closely related to the fleming strain of western equine encephalitis (wee) virus were cross-tested by serum dilution-plaque reduction neutralization. the results demonstrate that strains mcmillan, r-43738, ag80-646, bear 102091, and y62-33 are subtypes or varieties of western equine encephalitis virus strain fleming. ockelbo, kyzylagach, and babanki are subtypes of the prototype strain (egar 339) of sindbis virus. fort morgan and buggy creek viruses are closely related to each o ...	1988	2833129
identification of highlands j virus from a florida horse.	a virus, strain 64a-1519, isolated from the brain of a horse dying of encephalitis in florida in 1964, was identified as western equine encephalomyelitis (wee) virus. recently, we used polyclonal and monoclonal immune reagents to identify this isolate by comparing it to 2 strains of wee virus and to highlands j (hj) virus in hemagglutination-inhibition, immunofluorescent antibody, and plaque-reduction neutralization tests. these tests demonstrate that strain 64a-1519 is a strain of hj virus dist ...	1988	2849884
in vitro mechanisms of monoclonal antibody neutralization of alphaviruses.	we have previously identified at least eight epitopes on the e2 glycoprotein of venezuelan equine encephalomyelitis (vee) virus vaccine strain tc-83 by using monoclonal antibodies (mabs). several of these antibodies identified a critical neutralization (n) domain in competitive binding assays. passive transfer of these mabs protected animals from a lethal virus challenge. using radioactive, purified virus as a marker, we have demonstrated that antibody-mediated virus n, preattachment, can be eff ...	1988	2455383
impact of climate on western equine encephalitis in manitoba, minnesota and north dakota, 1980-1983.	information was collected on confirmed outbreaks of western equine encephalitis (wee) in north america east of the rockies for 1981 and 1983 (epidemic years) and 1980 and 1982 (non-epidemic years). the initial pattern of outbreaks in manitoba, minnesota and north dakota was determined for each year. backward (and in some instances forward) wind trajectories were computed for each day 4-15 days (incubation period) before the initial outbreaks of wee in a given area of province or state. during th ...	1988	2905669
western equine encephalitis virus is a recombinant virus.	the alphaviruses are a group of 26 mosquito-borne viruses that cause a variety of human diseases. many of the new world alphaviruses cause encephalitis, whereas the old world viruses more typically cause fever, rash, and arthralgia. the genome is a single-stranded nonsegmented rna molecule of + polarity; it is about 11,700 nucleotides in length. several alphavirus genomes have been sequenced in whole or in part, and these sequences demonstrate that alpha-viruses have descended from a common ance ...	1988	3413072
amplified elisa for the detection of western equine encephalitis virus from mosquitoes in manitoba, canada.	current monitoring systems to detect western equine encephalitis (wee) virus in mosquitoes involve isolation in suckling mice or cell culture followed by serological identification of the isolates obtained. studies were undertaken to develop an amplified elisa for the rapid detection of wee virus from mosquitoes. virus was inoculated onto primary chick embryo cells in 96 well plates, incubated at 37 degrees c for various time periods, monolayers were fixed, and an elisa performed. by this proced ...	1987	3443681
isolation of cache valley virus and detection of antibody for selected arboviruses in michigan horses in 1980.	blood samples collected in september and november 1980 from 87 horses in southwestern michigan were examined for virus isolation and for plaque-reduction neutralizing antibody against selected arboviruses. cache valley virus was isolated from the blood of a clinically normal horse in st joseph county in september. the age-specific antibody prevalence for cache valley virus indicated enzootic transmission in the study area. the high antibody prevalence and the lack of age-specific antibody preval ...	1987	3631684
leads from the mmwr. western equine encephalitis--united states and canada, 1987.		1987	3669204
factors influencing the transmission of western equine encephalomyelitis virus between its vertebrate maintenance hosts and from them to humans.	a simple model is used to explore the extent to which the uniquely comprehensive studies of western equine encephalomyelitis in kern county, california, by reeves and his colleagues over many years, explain the dynamics and epidemiology of the infection. it is concluded that not only does this series of integrated field and laboratory studies successfully account for these phenomena, to an extent which is unlikely to be substantially improved upon, not least because of the inherent difficulties ...	1987	3688320
infection of a poikilothermic cell line (xl-2) with eastern equine encephalitis and western equine encephalitis viruses.	eastern equine encephalitis (eee) was in cuba before the 1940s; the virus has been isolated from horses, birds, and rodents during epizootic as well as interepizootic periods. the only isolation of western equine encephalitis (wee) virus was from a sick pigeon found in the vicinity of havana university. both viruses can cause human disease; the isolation of wee virus from the centre of an urban area emphasises the need for the prompt isolation and rapid identification of these agents. the object ...	1987	3031203
western equine encephalitis--united states and canada, 1987.		1987	3116385
the ecology of western equine encephalomyelitis virus in the central valley of california, 1945-1985.	reeves' concept of the summer transmission cycle of western equine encephalomyelitis virus in 1945 was that the virus was amplified in a silent transmission cycle involving mosquitoes, domestic chickens, and possibly wild birds, from which it could be transmitted tangentially to and cause disease in human and equine populations. extensive field and laboratory studies done since 1945 in the central valley of california have more clearly defined the specific invertebrate and vertebrate hosts invol ...	1987	3318522
arbovirus isolations from mosquitoes collected during and after the 1982-1983 epizootic of western equine encephalitis in argentina.	mosquitoes were collected in santa fe and rio negro provinces, argentina, in 1982-1983 during a western equine encephalitis (wee) epizootic. totals of 153,084 mosquitoes from santa fe province and 484 from rio negro province were tested for virus in 2,351 pools. seventeen virus strains were isolated, all from santa fe collections, as follows: 4 wee, 6 venezuelan equine encephalitis, 1 st. louis encephalitis, 2 antequera, 1 maguari, 1 melao, 1 new vesiculovirus (calchaqui), and 1 gamboa. the wee ...	1987	2880521
host-feeding patterns of argentine mosquitoes (diptera: culicidae) collected during and after an epizootic of western equine encephalitis.		1987	2884317
the discovery decade of arbovirus research in western north america, 1940-1949.		1987	2891315
identification of aedes campestris from new mexico: with notes on the isolation of western equine encephalitis and other arboviruses.	an arbovirus survey was conducted during august 1985 at white sands missile range in southcentral new mexico following a suspected arboviral disease epizootic among feral horses. a total of 20,566 mosquitoes (18,505 females and 2,061 males) and 8,900 biting gnats were collected and assayed for virus. female mosquitoes were principally aedes campestris (54.8%), aedes dorsalis (30.4%) and culex tarsalis (13.2%). arboviruses were not isolated from biting gnats, but mosquitoes yielded a total of 37 ...	1986	2906989
complex-specific immunoglobulin m antibody patterns in humans infected with alphaviruses.	sera from humans with serologically confirmed eastern equine encephalitis, western equine encephalitis, pogosta (ockelbo), mayaro, ross river, and chikungunya virus infections were tested by immunoglobulin m (igm) antibody capture enzyme immunoassay. diagnostically useful igm antibody titers were detected, and selected sera with high igm antibody titers were tested for igm antibody with nine heterologous alphaviruses. the results provide evidence for the complex specificity of igm antibody and i ...	1986	3009526
specificity of immunoglobulin m and g antibody responses in humans infected with eastern and western equine encephalitis viruses: application to rapid serodiagnosis.	paired sera from 20 humans with eastern equine encephalitis (eee) virus infections and from 17 humans with western equine encephalitis (wee) virus infections, all with previously demonstrated fourfold or greater rises or falls in hemagglutination-inhibiting, complement-fixing, or neutralizing antibody titers, were tested for immunoglobulin m (igm) and igg antibodies by an enzyme immunoassay. all individuals with eee and 14 of 17 individuals with wee had igm antibody, some as early as 1 day after ...	1986	3009535
[virus-specific antibodies in persons inoculated with a bivaccine against eastern and western equine encephalomyelitis].		1986	3020802
relevance of detection of immunoglobulin m antibody response in birds used for arbovirus surveillance.	young chickens were inoculated with 5,000 pfu of eastern equine encephalitis (eee) virus and bled at intervals thereafter for determinations of hemagglutination-inhibiting (hi), neutralizing (n), immunoglobulin m (igm), and igg antibodies. hi, n, and igm antibodies were first detected 4 days after infection, and igg was detected 7 days after infection. all four antibodies persisted through day 90 after infection. hi, n, and igm antibody titers remained elevated and were not cross-reactive with t ...	1986	3021813
[stimulation of arbovirus reproduction in cell cultures by hormones].	the possibility of stimulation of reproduction and antigen production of arboviruses (tick-borne encephalitis, japanese encephalitis, western equine encephalomyelitis) in cell cultures (spev, chick embryo fibroblasts) by using various hormones (insulin, acth, hydrocortisone) and optimal temperatures was demonstrated. the stimulating effect depended upon the type of cell culture, virus, method of cell treatment, and manifested by a significant increase of the hemagglutinating and infectious activ ...	1986	3026097
properties of monospecific antibodies to the glycoprotein of western equine encephalitis virus.	monospecific (msp-) antisera against e1 and e2 glycoproteins of western equine encephalitis (wee) virus were prepared and examined for binding activities to whole virions, hemagglutination-inhibition (hi), neutralization (nt) and protection. both anti-e1 and anti-e2 msp-abs protected mice against wee virus challenge. a competition experiment with monoclonal antibodies showed that these msp-antisera appear to lack the antibody population for some epitopes involved in viral neutralization.	1986	2425229
an interspecific mosquito model for the mesenteronal infection barrier to western equine encephalomyelitis virus (culex tarsalis and culex pipiens).	culex tarsalis, a putative mosquito vector of western equine encephalomyelitis (wee) virus, is susceptible to peroral infection by wee virus. the nonvector mosquito, culex pipiens, has a very high peroral threshold of infection and is considered to be refractory. by parenteral inoculation, both mosquito species are equally susceptible. thus, cx. tarsalis and cx. pipiens represent an excellent model system to examine the mechanisms for the mesenteronal infection barrier to wee virus. diethylamino ...	1986	3706628
diagnosis of western equine encephalitis in an infant by brain biopsy.		1986	3725645
rapid and specific serodiagnosis of western equine encephalitis virus infection in horses.	paired sera from 28 nonvaccinated horses with serologically confirmed western equine encephalitis (wee) virus infections were evaluated for immunoglobulin (ig)m and igg directed against wee virus, by use of enzyme immunoassay. twenty-one of the horses developed greater than or equal to 4-fold increases or decreases in serum igm titers in paired serum samples, confirming the diagnosis of wee in these horses. of the remaining 7 horses, 1 had stable igm titers, 1 had a 2-fold increase in igm titer ...	1986	3729130
air conditioning and television as protective factors in arboviral encephalitis risk.	in california, the advent of television and air conditioned housing has coincided with a general decrease in mosquito-borne viral encephalitis cases in humans in the past 25 years. during this same period, levels of vector populations, virus activity in vectors, birds, and horses has been high at times. air conditioning and television encourage persons to remain indoors during summer evenings, the primary time when infected culex tarsalis transmit western equine encephalomyelitis and st. louis e ...	1986	3486605
western equine encephalitis surveillance in utah.	the history of wee surveillance in utah is reviewed, beginning with the 1933 outbreak involving 3,958 horses. the step by step formation of the utah mosquito abatement associations surveillance program from 1957 to the present is discussed. results of an enlarged sentinel chicken flock surveillance program in utah during 1983 (3 sero-conversions in september), 1984 and 1985 (no sero-conversion) show the lack of wee activity in the surveillance area.	1986	3507489
aerial adulticiding for the suppression of culex tarsalis in kern county, california, using low volume propoxur: 2. impact on natural populations in foothill and valley habitats.	a low volume formulation of propoxur wettable powder suspended in larvicidal oil was evaluated on 4 occasions in kern co., california during 1983 using fixed and rotary wing aerial application systems. culex tarsalis abundance was suppressed significantly by all sprays, although reduction below the virus maintenance threshold of 30 females per trap night was achieved only at one foothill site. western equine encephalomyelitis virus minimum infection rates decreased significantly after serial app ...	1985	3880226
sensitive enzyme immunoassay for detecting immunoglobulin m antibodies to sindbis virus and further evidence that pogosta disease is caused by a western equine encephalitis complex virus.	an antibody capture enzyme immunoassay (eia) was adapted for the detection of immunoglobulin m (igm) antibody to sindbis (sin) virus. sera from humans with a febrile illness characterized by rash and arthralgia in eastern finland (pogosta [pog] disease) and sweden (ockelbo disease) and from humans with western equine encephalitis (wee) virus infection in the united states were tested for igm antibodies by eia. seroconversions were documented in patients with pog disease and with wee virus infect ...	1985	3908469
arboviral infections of the central nervous system--united states, 1984.		1985	3923307
western equine encephalomyelitis virus: in vivo infection and morphogenesis in mosquito mesenteronal epithelial cells.	the infection and morphogenetic events associated with the replication of western equine encephalomyelitis (wee) virus within the mesenterons of aedes dorsalis and three strains of culex tarsalis are compared and contrasted. wee virus apparently penetrates mesenteronal epithelial cells in vivo through membrane fusion. profiles of apparent membrane fusion events were observed between virus particles and the microvillar surface of the mesenteron and naked nucleocapsids are observed intracellularly ...	1985	3993231
properties of monoclonal antibodies against glycoproteins of western equine encephalitis virus.	to analyze the biological activities of the alphavirus glycoproteins, eight different monoclonal antibodies against the two glycoproteins of western equine encephalitis virus were isolated. five of the eight monoclonal antibodies were shown to be specific for e1 and three for e2 protein by an enzyme-linked immunosorbent assay and by radioimmunoprecipitation. three of the five anti-e1 and all of the anti-e2 monoclonal antibodies inhibited hemagglutination by purified virions. one anti-e1 and two ...	1985	4020970
arbovirus investigations in argentina, 1977-1980. i. historical aspects and description of study sites.	this is the introductory paper to a series on the ecology of arboviruses in argentina. epizootics of equine encephalitis have occurred since at least 1908, principally in the pampa and espinal biogeographic zones, with significant economic losses; human cases of encephalitis have been rare or absent. both western equine and eastern equine encephalitis viruses have been isolated from horses during these epizootics, but the mosquitoes responsible for transmission have not been identified. a number ...	1985	4037184
the use of an animal-baited net trap for collecting mosquitoes during western equine encephalitis investigations in argentina.	a large net trap was used to sample mosquito populations attracted to horses at three sites each in santa fe and rio negro provinces, argentina, during the austral summer of 1984. these provinces, as well as others in argentina, were affected by a severe epizootic of western equine encephalitis (wee) during 1982-83. totals of 2,752 and 6,929 mosquitoes were collected in santa fe and rio negro provinces during five and three trap nights, respectively. culex mosquitoes of the subgenus culex were p ...	1985	2906656
effect of normal mosquito extracts upon arbovirus recoveries from mosquito pools.	titers of turlock (tur) and hart park (hp) viruses were reduced to undetectable levels when virus was mixed with a triturated suspension of uninfected (normal) 4th instar larvae of culex tarsalis prior to plaque assay in cell culture. there was a linear relationship between the number of larvae in the pool and the titer of virus recoverable. virus was undetectable when 1,000-10,000 pfu of either agent was added to pools that contained 25 or more larvae. suspensions of up to 25 adult male or fema ...	1985	2860815
arbovirus investigations in argentina, 1977-1980. ii. arthropod collections and virus isolations from argentine mosquitoes.	prospective surveys for arboviruses were carried out in santa fe, corrientes, and chaco provinces, argentina, aperiodically during 1977-1980. a total of 313,233 mosquitoes and 598 biting flies other than mosquitoes were collected and tested for virus in 5,197 and 45 pools, respectively. forty virus strains were isolated, all from mosquitoes, as follows: santa fe province: 4 gamboa group viruses from aedeomyia squamipennis, 1 strain each of st. louis encephalitis virus from culex pipiens quinquef ...	1985	2863989
arbovirus investigations in argentina, 1977-1980. iii. identification and characterization of viruses isolated, including new subtypes of western and venezuelan equine encephalitis viruses and four new bunyaviruses (las maloyas, resistencia, barranqueras, and antequera).	forty viruses isolated from mosquitoes between 1977 and 1980 in argentina have been identified and characterized. nineteen strains of vee virus, identical by neutralization (n) tests, were shown by hemagglutination-inhibition tests with anti-e2 glycoprotein sera to represent a new subtype vi of the vee complex. rna oligonucleotide fingerprints of this virus were distinct from subtype i viruses. the virus was not lethal for english short-haired guinea pigs, indicating that it is probably not equi ...	1985	2863990
arbovirus investigations in argentina, 1977-1980. iv. serologic surveys and sentinel equine program.	serologic surveys of wild and domestic birds, wild mammals, and horses were conducted during arbovirus field studies in argentina from 1977 through 1980, a non-epizootic interval. the prevalence of neutralizing antibodies to eastern equine encephalitis (eee) was consistently higher than to western equine encephalitis (wee) virus in all species and all areas. the presence of antibodies in short-lived avian species and in young unvaccinated horses and the demonstration of seroconversions in horses ...	1985	2863991
isolation and preliminary characterization of mutants of western equine encephalomyelitis virus with altered virulence in chickens.	a small plaque (sp) and four temperature-sensitive (ts) mutants of western equine encephalomyelitis virus (weev) were obtained from a highly virulent field isolate (bfs-1703) after mutagenesis with 5-azacytidine or nitrosoguanidine or following undiluted passage in mosquito cell culture. three ts mutants (158, 214, and 260) expressed stable ts phenotypes as determined both by six-hour leak yield and efficiency of plaquing (eop) analyses. progeny of ts mutant 214 grown at the nonpermissive temper ...	1985	2864389
biochemical and biological characteristics of epitopes on the e1 glycoprotein of western equine encephalitis virus.	antigenic determinants identified by monoclonal antibodies (mabs) on the e1 glycoprotein of western equine encephalitis (wee) virus have been characterized by their serological activity, requirements for secondary structure, expression on the mature virion, and their role in protecting animals from wee virus challenge. on the basis of a cross-reactivity enzyme-linked immunosorbent assay (elisa) and hemagglutination inhibition assay, eight antigenic determinants (epitopes) on the e1 glycoprotein ...	1985	2414904
arthropod-borne virus infections of the central nervous system.	arthropod-borne viruses (arboviruses) are an important cause of meningoencephalitis in north america. this article considers the common features of the four major cns arbovirus infections in this country and gives detailed descriptions of the individual virus infections.	1984	6503938
case records of the massachusetts general hospital. weekly clinicopathological exercises. case 50-1984. a 53-year-old man with fever and rapid neurologic deterioration.		1984	6095078
focal neurologic signs in western equine encephalitis.	focal neurologic signs developed in a 75-year-old woman who had presented with encephalitis. a diagnosis of western equine encephalitis was made from serologic findings. although she was improving clinically the patient died from acute dissection of an aortic aneurysm 11 days after admission to hospital. the pathological findings--perivascular infiltrates and multifocal necrosis in the deep grey matter--were consistent with the diagnosis of western equine encephalitis. similar findings in the ba ...	1984	6704848
lateralized eeg abnormalities in western equine encephalitis.		1984	6744162
a variant of western equine encephalitis virus with nonglycosylated e3 protein.	a variant clone (at/a125) of western equine encephalitis virus was isolated from a line of mosquito cells persistently infected with a temperature-sensitive parent strain, a125. variant-infected cells produced an altered form of pe2 protein which migrated with a higher electrophoretic mobility than wild type or a125 pe2. the altered pe2, like pe2 of wild type, was precipitated by anti-envelope proteins serum but not by anti-e1 serum. in pulse-chase experiments the altered pe2 protein was shown t ...	1983	6829167
structural proteins of western equine encephalitis virus: amino acid compositions and n-terminal sequences.	the structural proteins of western equine encephalitis virus, a member of the alphavirus group, have been characterized by the determination of their amino acid compositions and by n-terminal sequence analysis. more than 60 residues of the n-terminal sequences of each of the envelope glycoproteins have been determined. a comparison of these sequences with the previously determined sequences of two related alphaviruses. sindbis virus and semliki forest virus, strongly supports the view that all t ...	1983	6834471
sleep apnea and nocturnal hypoventilation after western equine encephalitis.	that viral encephalitis can produce daytime hypoventilation is well appreciated, but an association of this infection with the development of a prolonged disturbance of breathing during sleep once the ventilatory disorder during wakefulness has resolved, has not been reported. we describe a young male who required assisted mechanical ventilation in association with western equine encephalitis. normal waking ventilation returned over 3 to 4 wk, but frequent apneas and severe hypoventilation persi ...	1983	6849538
mutants of sindbis virus. iv. heterotypic complementation and phenotypic mixing between temperature-sensitive mutants and wild-type sindbis and western equine encephalitis viruses.	heterotypic complementation between temperature-sensitive (ts) mutants of sindbis (sin) and western equine encephalitis (wee) viruses occurs under appropriate conditions. one heterotypic pair, sin ts153 x wee ts39 showed efficient complementation, and four other combinations gave detectable complementation, indicating that these two viruses, which are closely related serologically and biochemically, are sufficiently closely related to complement each other functionally. cells mixedly infected wi ...	1983	6864194
serodiagnosis of western equine encephalitis virus infections: relationships of antibody titer and test to observed onset of clinical illness.	sera from horses and human beings with clinically diagnosed western equine encephalitis (wee) virus infections were tested for hemagglutination-inhibition (hi), complement-fixation (cf), and neutralizing (n) antibody to wee virus. these tests confirmed infection in 43.8% (hi), 56.3% (cf), and 80.4% (n) of horses and 54.5% (hi), 59.1% (cf), and 77.3% (n) of human beings. use of the n test as an adjunct to the hi and cf tests increased the likelihood of serologic confirmation to 91.7%. in both hor ...	1983	6618970
effect of temperature of extrinsic incubation on the vector competence of culex tarsalis for western equine encephalomyelitis virus.	culex tarsalis was a less competent vector of western equine encephalomyelitis (wee) virus after 2-3 weeks' extrinsic incubation at 32 degrees c than after incubation at 18 degrees or 25 degrees c. the high temperature itself was not directly detrimental to mosquito infection as all mosquitoes were initially infected, but subsequently some females were able to limit viral multiplication and/or dissemination. elevated maintenance temperatures enhanced the expression of modulation, and elevated la ...	1983	6625067
leads from the mmwr. arboviral encephalitides--united states, 1983.		1983	6644947
arboviruses from western utah, usa, 1967-1976.		1983	6135808
comparative arboviral susceptibility of female culex tarsalis (diptera: culicidae) collected in co2-baited traps and reared from field-collected pupae.		1983	6298431
opsonization of alphaviruses in hamsters.	immune elimination of alphaviruses in immunized hamsters appears to involve formation of virus/antibody aggregates which are subsequently cleared from the circulation by cells of the reticuloendothelial system (res). virulent strains of venezuelan (vee) and western equine encephalitis (wee) viruses which were cleared slowly from the circulation of nonimmune hamsters, were cleared rapidly when inoculated into the blood of immunized hamsters. likewise, when these viruses were mixed with specific h ...	1983	6311964
arboviral encephalitides--united states, 1983.		1983	6415386
teratological effects of western equine encephalitis virus on the fetal nervous system of macaca mulatta.	fetal rhesus monkeys were inoculated intracerebrally with an attenuated strain of western equine encephalitis virus. all animals developed microcephaly. twelve of sixteen monkeys developed ex vacuo hydrocephalus. all virus inoculated fetuses developed wee virus antibody. virus could not be recovered at the time of delivery. monkeys with the highest wee antibody titers showed the greatest degree of hydrocephalus.	1982	7064113
a temperature-sensitive mutant of western equine encephalitis virus with an altered envelope protein e1 and a defect in the transport of envelope glycoproteins.		1982	7080446
arbovirus subtyping: applications to epidemiologic studies, availability of reagents, and testing services.		1981	7030063
nucleoside triphosphate phosphohydrolase produced in bhk cells infected with western equine encephalitis virus is probably associated with the 82k dalton nonstructural polypeptide.		1981	6115512
permeability of the midgut basal lamina in the mosquito, culex tarsalis coquillett (insecta, diptera).	the permeability of the basal lamina of the midgut of the mosquito, culex tarsalis, was determined for engorged and unfed mosquito midguts both pre- and postfixed. a range of materials, with diameters from less than 2nm (lanthanum) through 90 nm, (polystyrene spheres), was examined. the permeability of the basal lamina was constant under all experimental conditions; 5--8 nm particles (colloidal thorium) were the largest to consistently permeate. the discussion is centered on the question of how ...	1981	6115555
hemolytic activity of the envelope glycoproteins of western equine encephalitis virus in reconstitution experiments.		1981	7210501
dissemination barriers for western equine encephalomyelitis virus in culex tarsalis infected after ingestion of low viral doses.	there are two dose-dependent barriers to the transmission of western equine encephalomyelitis virus in infected female culex tarsalis. in the first, virus multiplies in the mesenteron, but does not invade other tissues regardless of the length of extrinsic incubation. we call this the "mesenteronal escape" barrier. in some mosquitoes virus escapes from the infected mesenteron but a second barrier prevents infection of the salivary glands and perhaps neural tissues. we designate this the "salivar ...	1981	7212166
evidence for the presence of the minor capsid protein of western equine encephalitis virus.	a minor capsid protein was found in western equine encephalitis virus. the minor capsid protein appeared to be produced by proteolytic cleavage of part of the newly synthesized capsid protein in infected cells and to be incorporated into nucleocapsids.	1981	7213014
serum epidemiology of eastern, western and venezuelan equine encephalitides in mexico.	the presence of hi antibodies for the eastern, western and venezuelan equine encephalitis was investigated in 16,405 human sera collected in 47 communities in the mexican republic. it was found that there is a high percentage of individuals who have antibodies against venezuelan equine encephalitis. in turn, it was discovered that persons with western equine encephalitis virus antibodies live in the northwestern states of the country. very few cases with eastern equine encephalitis antibodies we ...	1981	7294943