transovarial transmission of st. louis encephalitis virus by culex pipiens complex mosquitoes.experiments were conducted to determine whether transovarial transmission (tot) of st. louis encephalitis (sle) virus occurs in culex pipiens complex mosquitoes, the principal vectors of sle virus in the central-eastern united states. in 1978, field-collected mosquitoes from memphis, tennessee, and mcleansboro, illinois, were used; during 1979, colonized mosquitoes from chicago, illinois, and memphis, tennessee, were used. mosquitoes were infected by feeding on viremic chicks inoculated with an ...19816266266
[tick-borne encephalitis - a short review]. 19816268909
[several yellow fever cases in an endemic area in ivory coast: serological and epidemiological evidence (author's transl)].1 - more than hundred febrile haemorrhagic jaundice cases with an unexpectedly high number of death happened in the north-west of the ivory coast between october 1977 and december 1977. it was the end of the rainy season and in this area, yellow fever is a dreadful eventuality. 2 - epidemiological and serological survey was immediately carried out. presence of numerous yellow fever potential vectors was well known and has been noticed in september 1977; there were some left in december 1977. the ...19816268925
difference in antibody reactivity between complement fixation and immune adherence hemagglutination tests with virus antigens.complement-fixing (cf) immunoglobulin m antibody to infantile gastroenteritis virus (a rotavirus) did not show the reactivity of immune adherence hemagglutination (iaha). early immunoglobulin g cf antibody produced both in patients and in guinea pigs experimentally infected with japanese encephalitis virus (a flavivirus) had weak reactivity in iaha test. however, late antibody showed higher titers by iaha than by cf. these results suggested that early antibodies with lower affinity are inefficie ...19816270189
genetic heterogeneity among saint louis encephalitis virus isolates of different geographic origin. 19816270878
genetic resistance to lethal flaviviral encephalitis. iii. replication of banzi virus in vitro and in vivo in tissues of congeneic susceptible and resistant mice.the replication of banzi virus, flavivirus, was compared in vitro and in vivo in tissues of congenic mice genetically resistant (c3h/rv) or genetically susceptible (c3h/he) to lethal infection. ultrastructural changes in brains of resistant and susceptible adult mice following intracerebral or intraperitoneal inoculation of virus also were compared. banzi virus replicated equally well in monolayer cultures of infant and adult brain, stimulated and non-stimulated macrophages and embryonic cells f ...19816271105
the alexander d. langmuir lecture. the pathogenesis of dengue. molecular epidemiology in infectious disease. 19816272572
genetic determinants of virus susceptibility: epidemiologic implications of murine models. 19816273199
the reaction of funambulus tristriatus tristriatus rattus blanfordi and suncus murinus to kyasanur forest disease virus. 19816273309
attenuation of turkey meningo-encephalitis virus in bhk21 cells.turkey meningo-encephalitis virus was adapted to bhk21 cell culture. cytopathic effects were characterized by rounding and detachment of cells within 48 hours. attenuation was achieved by 41 successive passages in bhk21 cell cultures. turkeys and japanese quail (coturnix coturnix japonica), kept under laboratory conditions and inoculated with the attenuated virus, did not develop symptoms of turkey meningo-encephalitis but reacted by the production of haemagglutination inhibition antibody. they ...19816273772
[serological survey for the prevalence of certain arboviruses in the human population of the south-east area of central african republic (author's transl)].a serological survey of antibodies to arboviruses was carried out in the human population of the south-east part of central african republic in april 1979. four hundred and fifty nine serum samples were tested using the haemagglutination inhibition test (h. i.) and fifty of them by the complement fixation test (c. f.). only 11% of the population tested had no h. i. antibodies against the following arboviruses: chikungunya, semliki-forest, sindbis, yellow fever, uganda s, west-nile, zika, bunyamw ...19816274526
[natural pathogenicity for man of an antigenic variant of soldado virus from morocco (author's transl)].pathogenicity of soldado virus was clearly established in the past for seabirds but remained questionable for man. in a scientist, repeatedly bitten by ornithodoros (a.) maritimus larvae at essaouira (morocco), the association of fever of unknown origin and of neutralizing antibody against an antigenic variant of soldado virus isolated from the same place, lead to the conclusion that this virus may act as a pathogen for man. epidemiological implications of such an observation are briefly discuss ...19816274527
zika virus, a cause of fever in central java, 1977 and 1978 selected in-patients at the tegalyoso hospital, klaten, indonesia who had recent onsets of acute fever were serologically studied for evidence for alphavirus and flavivirus infections. a brief clinical history was taken and a check list of signs and symptoms was completed on admission. acute and convalescent phase sera from 30 patients who showed evidence that a flavivirus had caused their illnesses were tested for neutralizing antibodies to several flaviviruses which occur in s ...19816275577
genetic resistance to lethal flavivirus encephalitis: effect of host age and immune status and route of inoculation on production of interfering banzi virus in vivo.phenotypic expression of resistance to banzi virus infection by c3h/rv mice develops at about 4 weeks of age and occurs when the virus is given at a peripheral inoculation site. in contrast, young or adult congenic c3h/he mice die with an encephalitic illness regardless of the route of inoculation. data are presented here which suggest that interfering virus (i.v.) production by mice genetically resistant to lethal flavivirus encephalitis may contribute to their survival. the level of i.v. in th ...19816275728
[effect of the tahyña virus on langat virus persistence in the central nervous system of the mouse].the features of development of a mixed infection in which one of the infectious agents (tahyña virus) had a marked immunodepressive activity and the other (langat virus) caused predominantly asymptomatic course of the disease were studied. successive infection with these agents increased the severity of the disease (lethality in monoinfection 7-18%, in mixed infection 57%). at the same time the duration of persistence in the brain of mice of langat virus but not of tahyña virus increased up to 1 ...19816278778
[modelling of a chronic infection in a cell culture of the brain of suckling syrian hamsters due to viruses of the tick-borne encephalitis complex].the capacity of 3 members of the tick-borne encephalitis virus complex (langat tp-21, sophyin, elantsev) differing in their biological properties to induce chronic infection in primary cultures of suckling syrian hamster brain cells (shb) was studied. three types of the infectious process were observed in these cells. langat tp-21 virus showed cytoproliferative activity in chronically infected shb cell cultures; formation of cell colonies and alternation of phases of destruction and repopulation ...19816278780
envelope protein of the flavivirus kunjin is apparently not glycosylated.the envelope protein e (formerly designated v3) of the flavivirus kunjin was not labelled with radioactive galactose, mannose or glucosamine during virus growth in vero cells. on electrophoresis through polyacrylamide gels containing sds, the envelope (e) protein migrated more rapidly than related intracellular virus-specified glycoproteins. furthermore, e had a density in cscl solution consistent with that of a protein lacking carbohydrate, and did not bind to concanavalin a-agarose. in contras ...19826279774
detection of japanese encephalitis virus immunoglobulin m antibodies in serum by antibody capture assay for detecting human immunoglobulin m (igm) antibodies to japanese encephalitis (je) virus was developed by using the antibody capture solid-phase radioimmunoassay approach (je igm acriaaa). heavy-chain-specific goat antihuman igm was first bound to the wells of a polyvinyl microtiter plate, and successive steps involved sequential binding of test sample igm, acetone-extracted mouse brain je antigen, and (125)i-labeled flavivirus hyperimmune human igg. among 20 patients hospitalized in b ...19826281305
passively acquired antibody to flavivirus in thai infants. 19816281922
[serological studies in research on arbovirus antibodies in the human population of the ribeira valley region. ii - survey of patients of pariquera-açú regional hospital, 1980]. 19816283622
[mechanisms of in vivo suppressive effect of togaviridae and bunyaviridae on the activity of effectors of graft vs host reaction].experiments on mice demonstrated the ability of 3 flaviviruses and 1 bunyavirus to suppress the activity of the effectors of the graft-versus-host (gvh) reaction. the conditions of the suppression of the primary immunological recognition were shown to differ in infections caused by different viruses. in experimental flavivirus infections caused by langat, dengue 2 or yellow fever (strain 17d) viruses t-suppressor cells were activated, and their activity was realized only in respect to syngeneic ...19826283771
infection enhancement of dengue type 2 virus in the u-937 human monocyte cell line by antibodies to flavivirus cross-reactive determinants.dengue type 2 virus replication was detected in the u-937 human monocyte cell line when the virus inoculum and the culture medium contained flavivirus antibodies diluted beyond their neutralizing titers. this was in marked contrast to yellow fever virus, which replicated very well in the absence of antibodies; however, 10-fold-higher yields of yellow fever virus could be obtained in the presence of flavivirus antibodies. these infection-enhancing antibodies were obtained from either a dengue typ ...19826284641
dengue virus-specific and flavivirus group determinants identified with monoclonal antibodies by indirect immunofluorescence.monoclonal antibodies produced against the four dengue virus serotypes identified four categories of reactions by immunofluorescence: flavivirus group reactive, dengue complex specific, dengue subcomplex specific (den-1, den-3), and dengue serotype specific. this is the first time that monospecific antibodies have been available for all of these unique antigenic determinants. hybridoma cell lines producing dengue type-specific antibodies have been deposited in the hybridoma cell bank of the amer ...19826285749
vector competence of culex pipiens quinquefasciatus for murray valley encephalitis, kunjin, and ross river viruses from australia.australian populations of culex pipiens quinquefasciatus say from brisbane, charleville, cairns, kowanyama (queensland), darwin (northern territory), mildura (victoria), and port hedland (western australia) proved to be either poorly susceptible or refractory to oral infection with low passage level murray valley encephalitis, kunjin, and ross river viruses. with respect to past or future epidemics of murray valley encephalitis or kunjin (both known to cause clinical encephalitis in man), and of ...19826285750
[use of the simple radial hemolysis technic for the detection of antibodies to various flaviviruses]. 19826289389
[heterogeneity of virus-specific flavivirus proteins].the polyacrylamide gel analysis of large intracellular virus-specific proteins nv5, nv4, and the intracellular form of structural protein v3 established differences in the electrophoretic mobility of each of these proteins formed in cells infected with tick-borne encephalitis, powassan, langat, and west nile viruses. it is assumed that these differences in the electrophoretic mobility of nv5, nv4 proteins, and the intracellular form of v3 protein reflect the differences in the primary structure ...19826289529
winter survival of blood-fed and nonblood-fed culex pipiens l.comparisons were made between groups of culex pipiens l. with different physiologic histories to test their ability to sucessfully overwinter under field conditions. on 14 december 1978, each group of mosquitoes was marked with a distinctive fluorescent dust and released inside an abandoned ammunition bunker at fort washington, maryland. to insure that dead mosquitoes could be dissected and information obtained on their ovarian development, a sample of females from each group was also released i ...19826289686
molecular epidemiology of tick-borne encephalitis virus: peptide mapping of large non-structural proteins of european isolates and comparison with other flaviviruses.nine virus-specified proteins were identified by sds-polyacrylamide gel electrophoresis in [35s]methionine-labelled chick embryo cells infected with tick-borne encephalitis (tbe) virus by comparison with mock-infected cells. these proteins were designated p91, p74, p72, p67, gp53(e), p47, p25, p15(c) and p14.5 according to their molecular weights. peptide mapping of p91, p67, gp53(e) and p47 from tbe virus-infected cells, as well as those of the corresponding proteins from west nile virus (wnv)- ...19826292351
antigenic relationships of flaviviruses with undetermined arthropod-borne contrast to most of the arthropod-borne flaviviruses, the flaviviruses with undetermined arthropod-borne status are probably disseminated only by direct contact with excreta (saliva, urine, feces, etc.); however, as yet undescribed arthropod transmission cycles may be found for some of them. twenty-two of these flaviviruses, including prototype and recently isolated strains, were compared. biologic properties were defined by infectivity titrations in suckling mice and vero, llc-mk2, and prima ...19826293325
restricted translation of the genome of the flavivirus kunjin in vitro.virion rna of kunjin virus was translated in rabbit reticulocyte lysates at a rate (7000 daltons/min) approaching that observed previously in vivo. as many as 18 polypeptides were translated and shown by tryptic peptide mapping to be closely related to one another and to contain some of the elements of envelope (e) and most of the elements of core (c) proteins of kunjin virus. none of the products resolved in gels were precipitated by antiserum to purified e protein, but the larger products were ...19826294228
development of an enzyme-linked immunosorbent assay for the identification of arthropod-borne togavirus antibodies.the applicability of the standard enzyme-linked immunosorbent assay (elisa) for the identification of togavirus infections was investigated. optimal concentration of gradient-purified antigen was 2.5 micrograms/well for alphaviruses or flaviviruses when coating polystyrene microtitre plates. a procedure for producing antigen in suckling mouse brain was developed. results obtained with elisa could be correlated with standard serology, but in general the elisa was more sensitive. the elisa was spe ...19826294229
[serological studies for research on arbovirus antibodies in a human population of the vale do ribeira region. iii. survey in inhabitants with cases of flavivirus rocio encephalitis]. 19826296991
comparative arboviral susceptibility of female culex tarsalis (diptera: culicidae) collected in co2-baited traps and reared from field-collected pupae. 19836298431
viruses recovered from mosquitoes and wildlife serum collected in the murray valley of south-eastern australia, february 1974, during an epidemic of encephalitis.pools of mosquitoes collected in the murray valley in february, 1974, during an encephalitis epidemic yielded 239 isolates of 11 distinct viruses. these included 39 isolates of mve virus, an incriminated causative agent of encephalitis in man, and 111 isolates of kunjin virus, a probable causative agent. an additional isolate of mve virus was recovered from the serum of a white-faced heron, ardea novaehollandiae. the other 9 viruses comprised the alpha-viruses ross river and sindbis, the flavivi ...19826299258
variation in arbovirus infection rates in species of birds sampled in a serological survey during an encephalitis epidemic in the murray valley of south-eastern australia, february 1974.there was extensive and exuberant breeding of waterbirds before and during an epidemic of arboviral encephalitis in the murray valley of south eastern australia in 1974. as estimated by haemagglutination inhibition tests on 432 bird sera collected between 4th and 13th february, 1974, infection with murray valley encephalitis virus, kunjin virus and possibly other flaviviruses was concentrated in species of the order ciconiiformes (55% positive) and pelecaniformes (41%), compared with only 5% in ...19826299259
an investigation of flavivirus infections of cattle in zimbabwe rhodesia with particular reference to wesselsbron virus.a three-part epidemiological investigation was made on flaviviruses:1. as a preliminary to tests on cattle sera from the field, the antigenic cross-reactivity of wesselsbron, spondweni, usutu, banzi, west nile and yellow fever flaviviruses was studied in antisera prepared in guinea pigs. as described earlier for flaviviruses, sera were found to be highly cross-reactive in haemagglutination-inhibition (hai) tests, less cross-reactive in complement-fixation (cf) tests and were virtually monospecif ...19806300226
mode of entry of a neurotropic arbovirus into the central nervous system. reinvestigation of an old controversy.the mechanism by which neurotropic arboviruses gain access to the central nervous system remains uncertain, although it is generally assumed that viremic infection results in growth across or passive diffusion through brain capillaries. in contrast to the natural reservoir hosts of these arboviruses, clinical hosts (e.g., horses, humans) have viremias of very brief duration and low magnitude. we investigated the question of neuroinvasion in 5- to 6-week-old syrian hamsters infected with st. loui ...19836300550
comparative vector competence of culex tarsalis and culex quinquefasciatus from the coachella, imperial, and san joaquin valleys of california for st. louis encephalitis louis encephalitis (sle) virus has continued to be active in the colorado desert region of southern california (coachella and imperial valleys) since 1973, while it has virtually disappeared from the sacramento and san joaquin valleys of central california. consequently, comparative vector competence studies were undertaken from 1978 to 1981 to evaluate the susceptibility of populations of culex quinquefasciatus and culex tarsalis from the san joaquin and coachella/imperial valleys to oral i ...19836301301
yellow fever and zika virus epizootics and enzootics in of monkey serology are presented which, together with past evidence, support the view that yellow fever (yf) virus circulates in its primary sylvan host populations, i.e., forest monkeys, in an enzootic state in bwamba county in western uganda but as series of epizootics in the forest-savanna mosaic zone of central uganda. evidence of an epizootic of zika virus at the zika forest near entebbe is described which occurred in two episodes, the first (in 1969) apparently following the build-up ...19826304948
amino acid compositions and amino-terminal sequences of the structural proteins of a flavivirus, european tick-borne encephalitis virus.n-terminal amino acid sequences of the three structural proteins e, c, and m of the flavivirus tick-borne encephalitis virus comprising 4, 17, and 4 amino acid residues, respectively, have been determined. each of these proteins has a unique n-terminal sequence. since none of the three proteins possesses an n-terminal methionine residue, none contains an unprocessed translation initiation sequence. the amino acid composition of the three proteins has also been analyzed. the c protein is rich in ...19836305006
interference between bunyaviruses in aedes triseriatus mosquitoes.inhibition of the replication of alternate california serogroup bunyaviruses in aedes triseriatus mosquitoes has been observed for mosquitoes previously infected with la crosse (lac) virus. by contrast, prior infection of mosquitoes with lac virus did not interfere significantly with the subsequent infection and replication of guaroa bunyavirus (bunyamwera serogroup), or heterologous viruses such as west nile flavivirus, or vesicular stomatitis rhabdovirus.19836305019
comparison of biological properties of st. louis encephalitis and rio bravo louis encephalitis (sle) virus, an arbovirus, and rio bravo (rb) virus, a non-arthropod-borne virus, are flaviviruses which cross-react in neutralization tests. several of their biological properties were compared. viral growth curves revealed that greater than 99% of infectious sle (parton) virus remained cell-associated in vero cells but was released slowly into the medium of infected bhk-21 cells. in contrast, rb (m-64) virus was released upon maturation into the fluids of vero and bhk-21 ...19836305222
arthropod-borne virus antibodies in sera of residents of kainji lake basin, nigeria 1980.a survey for haemagglutination-inhibiting arthropod-borne virus antibody was carried out in the kainji lake area of nigeria. of 267 persons tested, 139 (52%) and 158 (59%) had alphavirus and flavivirus group hi antibody, respectively. the prevalence of antibody to individual virus antigen is as follows: chikungunya, 45%; semliki forest, 25%; sindbis, 33%, yellow fever, 31%, dengue type 2, 46%; and zika 56%. the presence of high antibody rates to chikungunya, dengue type 2 and yellow fever viruse ...19836306872
serological studies on a case of laboratory dengue of the authors (y.o.), who had previously been immunized with japanese encephalitis (je) vaccine, showed symptoms of typical dengue fever 6 days after accidental infection with a newly isolated dengue type 4 virus strain from a patient with dengue hemorrhagic fever (dhf) in thailand. his sera were examined by hemagglutination inhibition (hi), complement fixation (cf) and neutralization (n) tests. the je n antibody titers of his sera were high even on the first day of the illness and remained ...19826307255
phenotypic changes in the flavivirus kunjin after a single cycle of growth in an aedes albopictus cell line.the properties of kunjin virus produced during acute infections of aedes albopictus (aal) mosquito cells were compared with those of the virus progeny from the c6/36 clone of mosquito cells and from vero cells. titres of 10(8) p.f.u./ml or greater were obtained from all cells, but significant haemagglutinin activity was associated only with progeny from vero and c6/36 cells. kunjin virus from aal cells adsorbed to goose erythrocytes and blocked haemagglutination by virus from vero or c6/36 cells ...19836308133
serologic evidence of natural togavirus infections in panamanian sloths and other vertebrates.plasmas of sloths and other central panamanian wild vertebrates were tested for plaque-reduction neutralizing (prn) antibodies against four flaviviruses and one alpha-virus. forty percent of 97 two-toed sloths, choloepus hoffmanni, and 8% of 168 three-toed sloths, bradypus variegatus, were specifically positive against st. louis encephalitis (sle) virus. the prevalence of antibody against sle virus was considerably higher in sloths than in any other group of wild vertebrates tested, including bi ...19836309027
identification of hitherto unrecognized arboviruses from ecuador: members of serogroups b, c, bunyamwera, patois, and minatitlan.three hundred seventy-nine virus isolates were obtained from mosquitoes collected and sentinel hamsters exposed in coastal ecuador from 1974 to 1978. these included four alphaviruses [venezuelan equine encephalitis 1b (1), venezuelan equine encephalitis 1d (35), western equine encephalitis (1) and eastern equine encephalitis (4)]; two flaviviruses [st. louis encephalitis (3) and naranjal (6)]; 11 bunyaviruses [maguari (243), playas (3), vinces (33), turlock (2), abras (5), babahoyo (3), acara (2 ...19836309029
a survey for arboviral antibodies in sera of humans and animals in lombok, republic of indonesia.sera were collected from humans, cattle, horses, goats, ducks, chickens, wild birds, bats and rats in lombok, indonesia, and were tested by haemagglutination inhibition (hi) for antibodies to je, zika, chik and rr. selected sera were tested by microneutralization tests for antibodies to the following viruses: je, zika, mve, tmu, lgt, kun, sep, den-2, chik, rr, get, sin, bun, bat and bak. human sera had je hi antibody in 135 (30%) of 446 tested. neutralization tests indicated that den-2, zika, tm ...19836309104
[use of species-specific immune ascitic fluids for identifying flaviviruses]. 19836310897
[epidemic hemorrhagic fevers]. 19836310907
antiviral activity released from aedes albopictus cells persistently infected with semliki forest virus.aedes albopictus (mosquito) cells persistently infected with semliki forest virus released an agent which inhibited virus production by a. albopictus cells infected with homologous virus. inhibition of virus production was accompanied by a marked reduction in the synthesis of viral rna and viral proteins. expression of the antiviral effect was prevented by pretreatment of cells with actinomycin. no analogous antiviral activity was detected in culture fluids of a. albopictus cells persistently in ...19836312089
the house sparrow (passer domesticus) as a sentinel for st. louis encephalitis virus.birds are the primary hosts for st. louis encephalitis (sle) virus in most of north america. because the increased prevalence of antibody in house sparrows (passer domesticus) has been related to human cases, this species has been frequently used as a sentinel of sle virus activity in urban areas. this study investigated the susceptibility of house sparrows to two strains of sle virus, measured antibody profiles, and evaluated the use of house sparrows in an urban surveillance system. house spar ...19836312819
a sero-epidemiological survey for certain arboviruses (togaviridae) in pakistan.complement-fixation test reactions to eight viruses of the family togaviridae were studied in 372 serum samples (157 rodents, 172 domestic animals, 43 humans) from pakistan. antibodies to each tested virus were detected. the highest over-all prevalence rates were for west nile (wn) (7.8%), japanese encephalitis (je) (3.2%) and zika (zika) (2.4%) viruses, followed by sindbis (sin), chikungunya (chik), uganda s (ugs) and royal farm (rf) viruses (1.6 to 1.3%). one human serum (male, age 58 years) r ...19836314612
variation in infectivity of saint louis encephalitis viral strains for culex pipiens quinquefasciatus (diptera: culicidae). 19836315940
brief-exposure break-bone fever. 19836315975
[effect of a bone marrow stimulator of antibody producers on virus-specific antibody formation in animals infected with flaviviruses].the injection of the marrow stimulator of antibody-producing cells (sapc) into animals infected with japanese encephalitis and tick-borne encephalitis viruses stimulated the formation of virus-specific antibodies in the infected animals, increasing antibody production 8- to 16-fold. such sapc-induced stimulation of the formation of virus-specific antibodies is observed in cases of both acute and chronic virus infection. the prospects of using the preparation of sapc are discussed.19836318482
immunofluorescent sites in vero cells infected with the flavivirus kunjin.the sites of replication and of accumulation of viral macromolecules were examined using fluorescent antibodies to viral products and to cell organelles. synthesis of envelope protein and its accumulation in a narrow rim around the nucleus were detected at 4 hours post infection; concurrently, a progressive change was observed in the rough endoplasmic reticulum from a fine to a coarse network emanating from around the nucleus. this change in the network was visible by light microscopy. the immun ...19836318692
the replication of rocio virus in brain tissue of suckling mice. study by electron electron microscopy studies, rocio virus particles were about 43 nm and spherically shaped. they were found within the cisternae of the endoplasmic reticulum and golgi complex of infected neurons. no precursor particles were detected nor virus budding was evident.19836318701
flavivirus infections in chiang mai area, thailand, in 1982.infection by je virus still constitutes major cause of encephalitis in chiang mai area, although some cases of possible dengue encephalopathy were observed. in spite of many apparent encephalitis cases, infection of vector mosquitoes by je virus was not demonstrated. virus isolation from hospitalized patients showed that the principal type of dengue virus circulating in chiang mai in 1982 was type 1 virus. seroepidemiological survey on healthy humans indicated that the northern part of chiang ma ...19836324386
[comparative study of glial cells infected with alpha-, flavi- and picornaviruses]. 19846324506
febrile illness in malaysia--an analysis of 1,629 hospitalized patients.we studied 1,629 febrile patients from a rural area of malaysia, and made a laboratory diagnosis in 1,025 (62.9%) cases. scrub typhus was the most frequent diagnosis (19.3% of all illnesses) followed by typhoid and paratyphoid (7.4%); flavivirus infection (7.0%); leptospirosis (6.8%); and malaria (6.2%). the hospital mortality was very low (0.5% of all febrile patients). the high prevalence of scrub typhus in oil palm laborers (46.8% of all febrile illnesses in that group) was confirmed. in rura ...19846324601
comparisons by peptide mapping of proteins specified by kunjin, west nile and murray valley encephalitis viruses.the relationships among virus-specified proteins of murray valley encephalitis (mve), kunjin (kun) and west nile (wn) viruses were investigated by peptide mapping of exhaustive proteolytic digests of radioactively labelled polypeptides. maps of the three structural proteins (e, c and m) derived from purified virions and of two non-structural proteins (nv5 and nv4) obtained from infected cells were compared. for each polypeptide considered, the peptide maps of the kun and wn virus-specified prote ...19836326723
primary viraemia responses of herons to experimental infection with murray valley encephalitis, kunjin and japanese encephalitis viruses.rufous night herons, pacific herons, little egrets and intermediate egrets were experimentally infected with murray valley encephalitis, kunjin or japanese encephalitis viruses. viraemias of at least one day's duration were detected in all birds except two intermediate egrets inoculated with a very low dose of kunjin virus and one rufous night heron inoculated with japanese encephalitis virus. there was usually a viraemia of 3 to 5 days' duration commencing on the first or second day and continu ...19836326724
primary antibody responses of herons to experimental infection with murray valley encephalitis and kunjin viruses.antibody responses of rufous night herons (nycticorax caledonicus) and little egrets (egretta garzetta) following infection with murray valley encephalitis and kunjin viruses were determined. haemagglutinin-inhibiting antibodies were first detected on day 5 or 6 after inoculation and increased rapidly, reaching maximum titres of 320 to 2560 between 10 and 20 days after inoculation. titres declined 20-320 between 60 and 120 days after inoculation, then tended to remain stationary. titres were 2- ...19836326725
[electron microscopy study of the midgut of ticks after experimental infection with karshi virus].the guts of h. asiaticum and h. anatolicum ticks infected with karshi virus and incubated at 22 degrees and 37 degrees c were studied. virus particles with morphological features of flaviviruses were found 5 days after infection in the cells of the gut of ticks incubated at 22 degrees c and within 24 hours postinfection in the gut cells of the ticks incubated at 37 degrees c. the possible effect of temperature on the rate of development and spread of the infectious process in the gut wall of the ...19846328768
serologic evidence for widespread infection with la crosse and st. louis encephalitis viruses in the indiana human population.the vast under-reporting of la crosse virus and st. louis encephalitis virus infections in indiana residents was evident when numerous inapparent infections were detected retrospectively using serum dilution neutralization analyses of serum obtained in november 1978-april 1979 from 10,208 persons (0.2% of the state's population). an antibody prevalence rate of 3.6% to st. louis encephalitis virus was detected in the sample population as a whole, with rates as high as 13.2% for residents of indiv ...19846328975
antibody response to dengue-2 vaccine measured by two different radioimmunoassay methods.two different radioimmunoassays were used to detect virus-specific antibodies in sera from human volunteers inoculated with an attenuated dengue type 2 (den-2) vaccine (pr-159/s-1). an indirect radioimmunoassay required purified den-2 virions for optimal reactivity but was 10 to 500 times more sensitive than neutralization or hemagglutination inhibition tests. an antibody capture radioimmunoassay was able to utilize crude antigens from either den-infected mouse brains or aedes albopictus cell cu ...19846330164
detection of specific immunoglobulin m antibody to different flaviviruses by use of enzyme-labeled enzyme immunoassay was developed for the detection of human immunoglobulin m (igm) antibody to different flavivirus antigens. the igm antibody of human sera was selectively bound to anti-igm antibody-coated solid-phase plates. flavivirus igm antibodies were then detected by use of various enzyme-labeled antigens. the flavivirus antigens (dengue type 2 virus, west nile virus, and tick-borne encephalitis virus) were produced in suckling mice. the antigens were labeled with horseradish peroxidas ...19846330165
[diagnostic value of serum igm determination in human infections caused by flaviviruses].since 1977, we have performed arboviruses' serosurveys in 330 patients by haemagglutination inhibition test. for 22 of them we have studied specific igm antibodies against flavivirus. the separation was done by sucrose-gradient density ultracentrifugation and igm antibodies were demonstrated by the hi test. the 22 igm tested sera were distributed as follows: 1) 7 positive sera corresponding to patients with a recent flavivirus infection; 2) 12 sera to test with a hi titer greater than or equal t ...19846330490
immunoglobulin m antibody capture enzyme-linked immunosorbent assay for diagnosis of st. louis encephalitis.sera from patients with st. louis encephalitis were tested with an immunoglobulin m (igm) antibody capture enzyme immunoassay (mac elisa). the assay used five reagents: antihuman igm, test serum, sucrose-acetone-extracted mouse brain antigen, broadly cross-reactive flavivirus monoclonal antibody conjugated to alkaline phosphatase, and substrate (p-nitrophenyl phosphate). mac elisa endpoint titers correlated (r = 0.893) with the absorbance value of a 1:100 dilution of patient serum. significant ( ...19846386882
rapid identification of dengue virus isolates by using monoclonal antibodies in an indirect immunofluorescence assay.type-specific monoclonal antibodies prepared against the four dengue (den) virus serotypes were evaluated for their ability to identify low-passage human and mosquito isolates from jamaica and west africa by an indirect immunofluorescence assay. serotyped human isolates from jamaican dengue fever patients included 12 den-1, two den-2, and five den-4 viruses. viruses from west africa included 84 den-2 mosquito strains as well as two den-1 and one den-2 from humans. results obtained using the immu ...19836401944
japanese encephalitis virus replication: studies on host cell nuclear involvement.replication, as measured by virus production, of both the flavivirus japanese encephalitis virus (jev) and the alphavirus venezuelan encephalitis virus (vev) was unaffected by short pulses of actinomycin d (act d) at early times postinfection (pi). replication of jev was found to be partially inhibited by continuous exposure to act d under conditions where vev replication was equally sensitive to the drug. jev replication proceeded normally in the presence of mitomycin c, a dna synthesis inhibit ...19836403379
preliminary report on arbovirus-antibody prevalence among patients in kuwait: evidence of congo/crimean virus infection.from two major hospitals in kuwait 502 sera were randomly selected from patients during the period december 1979 to october 1982. serological investigations demonstrated flavivirus activity in the area and antibody to congo/crimean haemorrhagic fever virus was found in 4% of the samples. clinical data indicate that some cases may have been due to recent congo/crimean virus infection.19846435292
heterogeneity of infection enhancement of dengue 2 strains by monoclonal dengue (den) 2 virus strains were studied for antibody-dependent enhancement (ade) of infection in p388d1 mouse macrophage-like cells by using a panel of five den 2 monoclonal antibodies. den 2 strains were of diverse temporal, geographic, and disease origins. by hemagglutination inhibition and a plaque-reduction neutralization test in llc-mk2 cells, two of the monoclonal antibodies were type specific and three were flavivirus group reactive. in llc-mk2 cells, the seven den 2 viruses each ...19846607288
a replication-efficient mutant of west nile virus is insensitive to di particle interference.a previous report described the isolation of a mutant of west nile virus (wnv) from culture fluid obtained from persistently infected genetically resistant c3h/rv mouse cells that replicates significantly more efficiently in cultures of c3h/rv cells than does the parental virus. this replication-efficient mutant, designated re-wnv, has now been found to be insensitive to interference by wnv defective interfering (di) particles. this characteristic was demonstrated by several means. the re-wnv mu ...19836612994
[cloning and primary structure of dna copies of genome fragments of the tick-borne encephalitis virus].rna of a flavivirus-tick-borne encephalitis virus (far-east, type 1, strain sofin) was subjected to reverse transcription and the dna copy was transformed into double-stranded dna by action of e. coli dna-polymerase (klenow's fragment) without primer. the hairpin structures were removed by s1 nuclease. oligo-dc ends were attached to ds-cdna thus obtained, and this dna was annealed with pbr322 plasmid cut by psti and equipped with oligo-dg termini. the recombinant plasmids were cloned in e. coli ...19836679771
electron microscopic observation of a newly isolated flavivirus-like virus from field-caught mosquitoes.of many unidentified virus strains which were isolated from field-caught mosquitoes by using c6/36 cells (a virus-sensitive clone of aedes albopictus cells), three strains which formed small size plaques (sp virus) in c6/36 cells were investigated by electron microscopy. although the sp virus strains did not react with antisera against known arboviruses in serological tests, they closely resembled flaviviruses in morphology. however, when they were compared to japanese encephalitis (je) virus, s ...19846707614
absence of dengue 2 infection enhancement in human sera containing japanese encephalitis antibodies.sera from 52 young adults resident in a rural area in north thailand were studied for plaque-reducing neutralizing antibodies against dengue (den) viruses types 1-4 and japanese encephalitis (je), and for den-2 infection-enhancing antibodies using a newly described microtest in the human monocyte cell line, u-937. infection-enhancing antibody titers in u-937 cells using a simplified micromethod were similar to results obtained by published methods using human peripheral blood leukocytes and a ma ...19846711745
antibody against viruses in maternal and cord sera: non-specific inhibitors are found to higher titre on the maternal side of the circulation.pregnancies were identified in which maternal igg antibodies against rubella virus were not detectable by single radial haemolysis. twenty paired maternal/cord sera were then tested for haemagglutination-inhibiting (hi) activity against rubella virus without kaolin pretreatment of the sera. in the absence of specific antibody, the hi activity observed could thus be ascribed to the effect of non-specific inhibitors. the hi activity in maternal sera was significantly (p less than 0.001) higher tha ...19846736640
differences between translation products of tick-borne encephalitis virus rna in cell-free systems from krebs-2 cells and rabbit reticulocytes: involvement of membranes in the processing of nascent precursors of flavivirus structural proteins.tick-borne encephalitis virus (tbev) rna was translated in extracts from krebs-2 cells and in rabbit reticulocyte lysates. in the former system, two polypeptides, p53 and p13, corresponding to envelope (e) and core (c) proteins of the virion, respectively, were synthesized preferentially. in contrast, the major product in reticulocyte lysates was represented by a heterogeneous set of high-molecular-weight polypeptides which did not appear to include p53 or p13. the reticulocyte lysates, however, ...19846740945
17d yellow fever virus infection of p388d1 cells mediated by monoclonal antibodies: properties of the macrophage fc receptor.thirteen igg monoclonal antibodies to the envelope protein of 17d yellow fever virus (17d yf) were produced. all of the antibodies, whether type-specific to 17d yf or flavivirus cross-reactive, mediated antibody-dependent enhancement (ade) of virus growth in p388d1 cells. there was no consistent relationship between ade titres and the degree or pattern of neutralizing and/or haemagglutination inhibition activity. monoclonal antibodies of different isotypes were used to investigate further the pr ...19836854270
replication of virulent and attenuated strains of yellow fever virus in human monocytes and macrophage-like cells (u937).virulent and attenuated strains of yellow fever virus were compared for their ability to grow in cultures of unstimulated leucocytes and monocytes derived from human peripheral blood, and of a macrophage-like cell line of human origin, u937. the extent of virus growth in leucocyte cultures varied depending on the strain of virus, multiplicity of infection, presence of diluted antibody in the culture medium but independently of the flavivirus immune status of the donor. the same pattern of differ ...19836860148
complement receptor mediates enhanced flavivirus replication in macrophages.evidence is presented that m phi complement receptors (cr3) mediate igm-dependent enhancement of flavivirus replication in the presence of complement. enhancement is blocked by pretreatment of macrophages with monoclonal antibody ml/70, which inhibits cr3 binding, but not by pretreatment with monoclonal antibody 2.4g2, which inhibits fcr binding.19836864163
west nile virus in pakistan. 1. sero-epidemiological studies in punjab province.serum samples collected during 1978-79 from residents of the chiniot and changa manga national forest (cmf) areas of punjab province, pakistan, had over-all neutralizing (n) antibody positive rates for west nile (wn) virus of 32.8% (n = 192) and 38.5% (n = 239), respectively. comparison of the age-specific antibody rates indicated that the pattern of exposure to infection was different in the two areas. samples from a 1968 serosurvey of residents of the cmf area had an age-specific n antibody pr ...19826926759
myocardial and pancreatic necrosis induced by rocio virus, a new flavivirus. 19806985865
passive hemolysis-in-gel with togaviridae arboviruses.radial hemolysis-in-agarose gel (hig) with members of the genera alphavirus and flavivirus is described. the test can be reproduced with goose and sheep erythrocytes sensitized at the optimal ph for each virus. human (o group), rooster, guinea pig, mouse and hamster erythrocytes were found to be unsuitable. the titer of immune ascitic fluids in hig coincides with the titer in hemagglutination inhibition. investigation of convalescent sera after laboratory infection suggests the possiblity of hig ...19806987193
lack of greater seroconversion of rhesus monkeys after subcutaneous inoculation of dengue type 2 live-virus vaccine combined with infection-enhancing antibodies.four groups of six nonimmune male rhesus monkeys were inoculated subcutaneously with formulations of dengue type 2 vaccine virus den-2/s-1. group a received 1.9 x 10(4) plaque-forming units of vaccine in normal human serum albumin diluent. group b received the same dose combined with a dengue type 2-immune human serum diluted 1:1,600, beyond its neutralization endpoint of 1:300, but having an immune enhancement titer of 250,000. groups c and d received 10-fold dilutions of these respective formu ...19817024129
monoclonal antibodies against the flavivirus west nile.monoclonal antibodies having three different specificities have been prepared against the egypt 101 strain of west nile virus (wnv). all were reactive against the envelope glycoprotein in radioimmune precipitation tests, and all enhanced wnv replication in the mouse macrophage line p388d1. one antibody, which is of igg2a subclass, had strong neutralizing activity against the homologous virus, although it failed to neutralize a different wnv strain. the other two antibodies, both of igg1 subclass ...19827061990
kadam virus (togaviridae, flavivirus) infecting camel-parasitizing hyalomma dromedarii ticks (acari: ixodidae) in saudi arabia. 19827086856
antibody capture immunoassay detection of japanese encephalitis virus immunoglobulin m and g antibodies in cerebrospinal fluid.immunoglobulin m (igm) and igg antibodies to japanese encephalitis virus (jev) were detected in acute-phase cerebrospinal fluid (csf) specimens from patients with acute encephalitis by using a solid-phase radioimmunoassay of the antibody capture type. of 12 patients with jev infections subsequently proven by hemagglutination inhibition serology, 11 had jev igm antibodies, as measured by antibody capture radioimmunoassay, in the first csf specimen (geometric mean titer, 1:2,500) compared with 0 o ...19827161371
glycoprotein detection in nitrocellulose transfers of electrophoretically separated protein mixtures using concanavalin a and peroxidase: application to arenavirus and flavivirus proteins. 19827165111
translation of tick-borne encephalitis virus (flavivirus) genome in vitro: synthesis of two structural polypeptides. 19817210510
terminal sequences of the genome and replicative-from rna of the flavivirus west nile virus: absence of poly(a) and possible role in rna replication. 19817269253
continuous cell lines from embryonic tissues of ticks (acari: ixodidae).six new cell lines were established in continuous culture from embryonic tissues of ixodid ticks. four were from dermacentor variabilis and two from d. parumapertus. the cells are mostly fibroblastic and diploid. mosquito-borne viruses (chikungunya, o'nyong, yellow fever, and st. louis encephalitis) as well as tick-borne ones (langat, powassan, colorado tick fever, kemerovo, and sawgrass) replicated in certain of these cell lines, but a nonvector-borne flavivirus, modoc, did not. an underscribed ...19817275139
a survey of virus infection in sub-antarctic penguins on macquarie island, southern ocean.serums from 1002 penguins of 4 species on macquarie island, a sub-antarctic island in the southern ocean, were examined for antibody to newcastle disease virus (ndv), influenza a virus, avian paramyxovirus, alphavirus and flavivirus. no evidence of haemagglutination-inhibition antibody to influenza a virus or alphavirus was detected. serums from 6% of royal penguins sampled gave positive reactions to ndv while the other 3 species were negative. antibody to a flavivirus and an avian paramyxovirus ...19817340785
neuropathology of s. paulo south coast epidemic encephalitis (rocio flavivurus).the neuropathology of 8 cases of s. paulo south coast epidemic encephalitis (rocio flavivirus), a new arbo b virus encephalitis, is described. the topographic pattern of the lesions appears to be almost specific. the gray matter is predominantly affected. interstitial mononuclear infiltration, microglial proliferation and perivascular lymphocytic cuffing were seen. neuronophagia was seldom seen except during the acute phases of the disease. throughout the neuraxis, the gray matter was affected t ...19807359160
preliminary characterization of glycopeptides derived from glycoproteins specified by the flavivirus kunjin. 19807395111
limitations of the complement-fixation test for distinguishing naturally acquired from vaccine-induced yellow fever infection in flavivirus-hyperendemic areas.on the basis of previous studies, it has long been stated that 17d yellow fever (yf) vaccine generally does not induce complement-fixing (cf) antibodies, and that the presence of cf antibodies could be used in epidemiological studies to distinguish individuals infected with wild yf virus from vaccinated persons. in january 1979, seroepidemiological investigations were conducted during a yf epidemic in the gambia, west africa. since a mass vaccination campaign was also in progress, it was importa ...19807406113
formation of polymeric glycoprotein complexes from a flavivirus: tick-borne encephalitis virus.treatment of tick-borne encephalitis (tbe) virus with triton x-100 (tx-100), octylglucoside (og) or cetyltrimethylammonium bromide (ctab) caused dissociation of the virus envelope into dimers or monomers of the glycoprotein v3. by centrifugation into detergent-free sucrose density gradients, these subunits were found to reassociate and to form haemagglutinating homogeneous glycoprotein complexes sedimenting at 15 to 16, 16 to 18 and 11 to 23s after tx-100, og and ctab treatment, respectively. gl ...19807420059
[arboviruses - structure and classification (author's transl)].the larger, biologically defined, set of arboviruses contains sub-sets representative of a number of different taxons. arboviruses classified on serological grounds into groups a and b are now placed respectively into the genera alphavirus and flavivirus, which form part of the family togaviridae. the recently defined family bunyaviridae contains almost 200 different arboviruses, serologically divisible into at least 24 different serogroups. the family reoviridae includes the genus orbivirus whi ...19807442509
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