rates of infection in, and transmission of, african horse-sickness virus by aedes aegypti mosquitoes.very low infection rates (less than 3%) were obtained when aedes aegypti mosquitoes ingested blood contained 5.8--6.5 log10 mld50/0.02 ml african horse sickness virus (ahsv). when a. aegypti mosquitoes were inoculated intrathoracically with virus, however, high infection rates were achieved. mosquitoes infected by inoculum failed to transmit virus to embryonated hens eggs by bite, and virus could not be detected in membrane or blood when inoculated mosquitoes were allowed to engorge on uninfecte ...197829475
characterization of the tubules associated with the replication of three different orbiviruses. 1979218352
inactivation of african horse-sickness virus by betapropiolactone and by ph.the inactivation of several types of african horse sickness virus (ahsv) by ph and by betapropiolactone (bpl) was studied. at 19 degrees - 22 degrees c the virus was stable between ph 6.0 and 10.4, whether suspended in mouse brain or in serumfree buffer. below ph 5.6 and above ph 10.9, more than 99 per cent of infectivity was inactivated within 15 minutes. the addition of 50 per cent serum did not influence ph stability. disinfection in the presence of citric acid and caustic soda is briefly dis ...1975237497
elephants and zebras as possible reservoir hosts for african horse sickness virus. 1977860390
african horse sickness virus antibodies in northern nigeria 1974--1975. 1977877421
a gel electrophoretic study of the protein and nucleic acid components of african horsesickness virus.the physico-chemical structure of african horsesickness virus (ahsv) is compared with that of some of the other members of the reoviridae, and in particular with that of bluetongue virus (btv), the type strain of the orbivirus genus. this study adduces evidence of a great similarity between the gel electrophoretic patterns of the polypeptides of ahsv and btv. the molecular mass values of the 7 ahsv polypeptides range between 0,30 x 10(5) and 1,46 x 10(5) dalton, a variation similar to that of bt ...19761023091
the growth of african horse-sickness virus in embryonated hen eggs and the transmission of virus by culicoides variipennis coquillett (diptera, ceratopogonidae).seven-day-old embryonated hen eggs were infected with african horse sickness virus by the yolk sac and intravenous routes. virus reached a high titre in the blood of infected embryos. culicoides variipennis midges which took a blood meal from infected eggs became infected with virus, and after 7 days at 26 degrees - 27 degrees c transmitted african horse sickness virus to uninfected eggs. c. variipennis may therefore be considered a biological vector of african horse sickness virus in the labora ...19751169930
the multiplication of african horse-sickness virus in two species of culicoides (diptera, ceratopogonidae).type 9 african horse-sickness virus multiplied to a high titre in both culicoides nubeculosus and c. variipennis after intrathoracic inoculation and in c. variipennis after oral ingestion. the orally infected c. variipennis were able to transmit the virus by biting after 13 days incubation at 26 degrees c but not after 6 days incubation. intrathoracically inoculated c. variipennis were able to transmit the virus after 4 days incubation. it is suggested that c. variipennis can act as a biological ...19751169931
letter: ahs vaccine. 19761258291
characterization of the genes encoding two of the major capsid proteins of epizootic haemorrhagic disease virus indicates a close genetic relationship to bluetongue virus.the sequences of the genes of two of the major capsid proteins of epizootic haemorrhagic disease virus serotype 1 (ehdv-1, orbivirus genus, reoviridae) have been determined by analyses of cdna clones representing the l2 and s7 rna segments. the ehdv-1 s7 rna segment, which encodes the vp7 core protein, is 1162 nucleotides in length and has the capacity to encode 349 amino acids (m(r) 38,243). the ehdv-1 l2 rna segment, which encodes the outer capsid vp2 protein (m(r) 113,249) is 2968 nucleotides ...19921321879
comparison of the major structural core proteins of tick-borne and culicoides-borne orbiviruses.comparison of sequence data for broadhaven (brd) virus, a tick-borne orbivirus, and bluetongue virus (btv), the type species of the genus, indicated that rna segments 2 and 7 of brd virus encode the two structural core proteins, vp2 and vp7, respectively. segment 2 is 2792 nucleotides in length with a coding capacity for a protein (vp2) of 908 amino acids and a net charge of +8.5 at neutral ph. segment 7 is 1174 nucleotides in length with a coding capacity for a protein (vp7) of 356 amino acids ...19921328474
the complete sequence of african horsesickness virus serotype 4 (vaccine strain) rna segment 5 and its predicted polypeptide compared with ns1 of bluetongue virus.the complete sequence of rna segment 5 of the african horsesickness virus serotype 4 (ahsv-4) vaccine strain was determined from cdna clones inserted into pbr322. the rna is 1751 bp long (m(r) 1.12 x 10(6)) and contains an open reading frame encoding a protein of 548 amino acids (m(r) 63,122) with a net charge of +0.5 at neutral ph. a comparison of the sequence of ahsv-4 segment 5 with that of segment 6 of bluetongue virus (btv) serotypes 10 and 17 revealed 49.2% and 48.9% nucleotide similarity, ...19921328499
evolutionary relationships among the gnat-transmitted orbiviruses that cause african horse sickness, bluetongue, and epizootic hemorrhagic disease as evidenced by their capsid protein sequences.the amino acid sequences of four major capsid proteins of african horse sickness virus (serotype 4, ahsv-4) have been compared with those of bluetongue virus of sheep. epizootic hemorrhagic disease virus of deer, and the phylogenetic relationships established. complete nucleotide sequence analysis of three rna segments (l2, l3, and m6) of ahsv-4 and their encoded products, vp2, vp3, and vp5, together with previously published data for vp7 (roy et al., 1991), have revealed that of the four capsid ...19921329319
susceptibility of aedes krombeini cell line to some arboviruses.the susceptibility of the newly established ae. krombeini cell line (nivi-ak-453) to six arboviruses, belonging to four different families, was studied. sindbis (sind), vesicular stomatitis (vsv) chandipura (chp) and african horse sickness (ahs) viruses multiplied in these cultures. a four-to-five-fold increase in the virus titres was observed. the maximum titre of sind, vsv, chp and ahs viruses were observed on 1st, 4th, 3rd and 10th post infection days, respectively. a steady and significant i ...19921335966
african horse sickness and equine infectious anaemia serology in the gambia. 19921339038
preliminary findings for an inactivated african horsesickness vaccine using binary ethyleneimine.investigation studies on inactivated african horsesickness vaccine using binary ethyleneimine were conducted. the inactivation process of virulent type-9 strain using the above inactivant revealed complete virus inactivation at 18, 48 and 84 h post-treatment with inactivant concentrations of 0.004, 0.003 and 0.002m, respectively, without detection of residual virus. an inactivant concentration of 0.003m is recommended and no changes in viral antigenic properties were noticed in complement fixati ...19921339986
prevalence of complement-fixing antibody to the african horse sickness virus in domestic animals in nigeria.the occurrence of antibodies against the african horse sickness virus was investigated in 246 domestic animals (horses, donkeys, camels, dogs) in various regions of nigeria by means of the complement-fixing rate. 34% of the sera tested were positive: 75% in donkeys, 68% in horses, 19% in camels, and 9% in dogs. among the horses, those of 6 to 15 years of age had higher than average prevalence rates than the other age groups. stallions from the northern regions had higher prevalence rates than ma ...19921340757
expression of the major core antigen vp7 of african horsesickness virus by a recombinant baculovirus and its use as a group-specific diagnostic reagent.the major core protein, vp7, of african horsesickness virus serotype 4 (ahsv-4), the aetiological agent of a recent outbreak of the disease in southern europe, was expressed in insect cells infected with a recombinant baculovirus containing a cloned copy of the relevant ahsv gene (s7). analyses of its biochemical and antigenic properties confirmed the authenticity of the protein expressed. the high-level expression of vp7 under the control of the strong polyhedrin promoter of autographa californ ...19921378881
vectors of african horse sickness in the cape verde islands. 19921441165
electron microscopic evidence for endothelial infection by african horsesickness virus. 19921448905
african horse sickness in spain.the aetiology, pathogenesis and epizootiology of african horse sickness (ahs) are reviewed with special reference to recent outbreaks in the iberian peninsula. ahs is a highly fatal insect-borne viral disease of equidae. it is caused by an orbivirus (family reoviridae) and nine serotypes are recognised. outbreaks occurred in central spain in 1987 and in southern regions of the iberian peninsula in 1988, 1989 and 1990. all were associated with serotype 4 of the virus, whereas other occurrences of ...19921481352
diagnostic methods for african horsesickness virus using monoclonal antibodies to structural and non-structural proteins.a panel of 32 hybridoma cell lines secreting monoclonal antibodies (mabs) reactive with african horsesickness virus serotype 4 (ahsv-4) has been developed. four of the mabs recognized the major core antigen vp7, twenty recognized the outer capsid protein vp2 and eight reacted with the non-structural protein ns1. with the vp7-specific mabs a rapid and sensitive double antibody sandwich immunoassay has been developed to detect viral antigen in infected vero cells and in spleen tissue from ahsv-inf ...19921481354
production and properties of monoclonal antibodies against african horsesickness virus, serotype 3.four polyethylene glycol-mediated cell fusions yielded a total of 23 monoclonal antibodies (mcabs) specific for african horsesickness virus (ahsv). two recognised the major core structural polypeptide, vp7, while one each was specific for the outer capsid proteins, vp2 and vp5. the remainder co-precipitated both vp2 and vp7. an inhibition elisa and radio-immunoprecipitation revealed two types of co-precipitating mcabs, distinguishable from each other by the different relative amounts of the two ...19921513593
detection of african horsesickness virus in infected spleens by a sandwich elisa using two monoclonal antibodies specific for vp7.a sandwich enzyme-linked immunsorbent assay (elisa) for rapid detection of african horsesickness virus (ahsv) in infected spleens or cell culture supernatant was developed. this method uses two monoclonal antibodies (mabs) which recognize two non-overlapping epitopes of the major core protein (vp7) to coat the solid phase, and one labeled with biotin as second antibody. this elisa was evaluated for its ability to detect ahsv in infected spleens resulting in a sensitivity of 97.4% and a specifici ...19921517353
identification and characterization of the structural and nonstructural proteins of african horsesickness virus and determination of the genome coding assignments.proteins present in purified african horsesickness virus (ahsv) and in infected cells were analyzed by sds-polyacrylamide gel electrophoresis. twelve viral proteins were identified, one minor and four major structural proteins, three major and two minor nonstructural proteins, as well as variable amounts of two additional structural proteins. cell-free translation of total ahs virion rna in a rabbit reticulocyte system resulted in the synthesis of proteins which were qualitatively and quantitati ...19921531096
the detection of african horse sickness virus antigens and antibodies in young equidae.four ponies were each inoculated with a different serotype of african horse sickness virus (ahsv) which had been passaged through cell culture in order to achieve attenuation. three of the ponies died suddenly after showing mild clinical signs, the fourth pony remained clinically normal and was killed at day 38. infectious ahsv was isolated from blood samples collected at intervals from all four ponies. positive antigen elisa reactions were only observed with blood samples from two of the ponies ...19921547837
encephalitis and chorioretinitis associated with neurotropic african horsesickness virus infection in laboratory workers. part i. clinical and neurological observations.four laboratory workers from the same vaccine-packing facility developed at different times over an 8-year period an illness characterised by encephalitis (in 3 workers) and uveochorioretinitis (in 4). low complement fixation titres were detected in all 4 patients to african horsesickness (ahs) virus and enzyme immunoassay and plaque reduction neutralising tests were positive, the latter against both serotypes 1 and 6. five of 15 laboratory workers from the same facility who were healthy on clin ...19921574746
encephalitis and chorioretinitis associated with neurotropic african horsesickness virus infection in laboratory workers. part ii. ophthalmological findings.four laboratory workers developed uveitis-chorioretinitis, associated with encephalitis in 3 cases. the retinitis was characterised by haemorrhages and areas of retinal oedema, most marked over the posterior polar regions, and was associated with exudative retinal detachments. the lesions progressed over weeks and showed a severe retinal arterial vasculopathy with arteriolar narrowing, ghost vessel formation and the development of optic atrophy. the picture in 2 of the patients resembled that of ...19921574747
encephalitis and chorioretinitis associated with neurotropic african horsesickness virus infection in laboratory workers. part iii. virological and serological investigations.four cases of encephalitis with chorioretinitis occurred in the vaccine-packing section of a veterinary research institute: 1 in 1982, 1 in 1985 and 2 in 1989. no viruses were isolated from patients and serological tests failed to reveal significant antibodies to a range of viruses incorporated in veterinary vaccines or to other likely pathogens, except for low titres of complement-fixing antibody to african horsesickness (ahs) virus in all 4 patients. in confirmatory tests, high enzyme immunoas ...19921574748
encephalitis and chorioretinitis associated with neurotropic african horsesickness virus infection in laboratory workers. part iv. experimental infection of the vervet monkey (cercopithecus pygerythrus).neurotropic vaccine strains of african horsesickness (ahs) virus types 1 and 6 were implicated as the possible aetiological agents in 4 cases of encephalitis and uveochorioretinitis in laboratory workers accidentally exposed to the freeze-dried vaccine preparations of the virus. to date, ahs virus has not been known to infect man. to ascertain whether or not primates were susceptible to infection with ahs virus, vervet monkeys (cercopithecus pygerythrus) were inoculated, either transnasally or i ...19921574749
an attempt to define the host range for african horse sickness virus (orbivirus, reoviridae) in east africa, by a serological survey in some equidae, camelidae, loxodontidae and carnivore.a survey was carried out in horse, zebra, elephant, camel, sheep and goat and wild carnivore sera for virus-serum neutralising antibody to the nine type strains of african horse sickness virus. antibody was found amongst the horse, zebra and elephant sera to all nine different strains. no antibody was detected in any sera from camels, sheep and goats. none was found in sera from hyaena and jackals in this series but had been detected earlier.19921615634
a review of african horse sickness with emphasis on selected vaccines. 19921626876
the complete sequence of the group-specific antigen, vp7, of african horsesickness disease virus serotype 4 reveals a close relationship to bluetongue virus.the complete sequence of the s7 rna that codes for the major group-specific coat protein. vp7, of african horsesickness virus serotype 4 (ahsv-4) was determined from cdna analyses and found to be 1179 nucleotides in length. one single open reading frame of 353 codons was observed defining a protein of mr 38,107 with a net charge of -1.5 at neutral ph. comparison of the ahsv-4 vp7 sequence with that of bluetongue virus serotype 10 revealed an overall similarity of 44%, with the amino- and carboxy ...19911646273
the use of a membrane feeding technique to determine the infection rate of culicoides imicola (diptera, ceratopogonidae) for 2 bluetongue virus serotypes in south africa.culicoides spp. in the lowveld of the northern transvaal, republic of south africa, were fed bluetongue virus serotypes 3 and 6 and african horsesickness virus serotype 1 through latex and chicken skin membranes. after an incubation period of 10 days at 25-27 degrees c, the infection rate of c. imicola for bluetongue virus serotypes 3 and 6 was established at 31% and 24% respectively. no african horsesickness virus could be recovered. the membrane feeding technique and handling procedures proved ...19911646980
a comparison of the nucleotide sequences of cognate ns2 genes of three different orbiviruses.the genes encoding nonstructural protein ns2 of african horsesickness virus (ahsv) and epizootic hemorrhagic disease virus (ehdv) were cloned, sequenced, and compared to the ns2 gene of bluetongue virus (btv). nucleotide similarity ranged from 53 to 60%. the length of the proteins varied from 376 amino acids (ehdv) to 365 amino acids (ahsv). the n-terminal half of ns2 is more conserved (+/- 58% similarity) among the three orbiviruses, while the c-terminal half contains a 120 amino acid region of ...19911656603
vp2 is the major exposed protein on orbiviruses. 19911759907
the use of elisa for the detection of african horse sickness viruses in culicoides midges.the use of elisa for the detection of african horse sickness viruses (ahsv) in midges preserved in 5.0% formalin was evaluated. no differences were detected by elisa when testing ahsv infected batches of culicoides midges collected in diluent with or without the addition of formalin. the elisa was considered highly sensitive and easily distinguished between non-infected midges and batches containing varying numbers of infected and non-infected midges. positive elisa reactions were detected with ...19911804852
a serogroup specific enzyme-linked immunosorbent assay for the detection and identification of african horse sickness viruses.a serogroup specific, indirect, sandwich elisa was developed for the rapid detection of african horse sickness virus and viral antigens in field samples or in infected tissue cultures. the assay was shown to be highly sensitive and capable of providing confirmation of clinical diagnosis within one day. the results demonstrated that this elisa will be useful for epidemiological surveillance of insect and mammalian host populations.19911864909
antibodies in horses, mules and donkeys following monovalent vaccination against african horse sickness.a total of 256 sera collected from three species of domesticated equidae in four different spanish provinces were examined 1-4 months after the administration of attenuated monovalent african horse sickness virus (ahsv) serotype 4 vaccine. approximately 10% of the sera were negative by elisa, virus neutralization, agar gel immuno-diffusion and complement fixation tests. similar negative reactions were recorded with sera from two ponies after experimental primary vaccination. the rapid rise in an ...19911902185
a comparison of the genes which encode non-structural protein ns3 of different orbiviruses.the segment 10 (s10) genes of african horsesickness virus (ahsv), palyam virus and epizootic haemorrhagic disease virus were translated in vitro in a rabbit reticulocyte lysate system. each of the s10 genes encoded two proteins ns3 and ns3a, which were shown to be related by peptide mapping. cloned copies of the s10 genes of two ahsv serotypes (ahsv-3 and ahsv-9) and palyam virus were sequenced and compared to each other and to the nucleotide sequence of bluetongue virus (btv) gene s10. two in-p ...19912033391
laboratory confirmation of african horsesickness in the western cape: application of a f(ab')2-based indirect elisa.recently a suspected outbreak of african horsesickness in the western cape province resulted in the deaths of four foals and one adult horse. spleen samples from these animals were subjected to analysis by an enzyme-linked immunosorbent assay (elisa) which uses f(ab')2 fragments of immunoglobulins to detect african horse sickness virus (ahsv) antigens. the results of the immunoassay were compared with those obtained by isolation followed by serotyping as is currently applied by the reference cen ...19912052314
a competitive elisa for the detection of group-specific antibodies to african horse sickness virus.a competition enzyme-linked immunosorbent assay (elisa) has been developed for the rapid identification and quantification of antibodies against african horse sickness (ahs) in sera from solipeds. the data showed the elisa to be sensitive, specific and reliable. more than 1600 sera from 37 different countries were examined and results compared with those obtained by agar gel immuno-diffusion (agid) tests. in no case did any of 775 sera from countries where ahs has never been reported and where a ...19902108871
african horse sickness in saudi arabia. 19902118696
laboratory diagnosis of african horse sickness: comparison of serological techniques and evaluation of storage methods of samples for virus isolation.five serological methods of diagnosing african horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of african horse sickness virus (ahsv1 through ahsv9): agar gel immunodiffusion (agid), indirect fluorescent antibody (ifa), complement fixation (cf), virus neutralization (vn), and enzyme-linked immunosorbent assay (elisa). the 5 tests were also compared using a panel of field samples, convalescent equine sera with a ...19902128615
purification and characterization of the major group-specific core antigen vp7 of bluetongue virus synthesized by a recombinant baculovirus.the major core protein, vp7, of bluetongue virus serotype 10 (btv-10) has been purified from insect cells infected with a genetically manipulated recombinant baculovirus. the high level expression of vp7 (in excess of 100 mg per litre of culture) and its presence in the soluble fraction of infected cells following lysis by detergent has allowed the purification of the protein virtually to homogeneity (95%) by a simple two-step procedure of ammonium sulphate fractionation and ion-exchange chromat ...19902174958
isolations of african horse sickness virus from vector insects made during the 1988 epizootic in spain.this paper describes the first isolations of african horse sickness virus (ahsv) from insects in spain. seven isolations of ahsv serotype 4 were made; four from culicoides imicola a known vector of the virus elsewhere, two from mixed pools of culicoides species not including c. imicola and one from blood engorged mosquitoes. three further isolations of ahsv serotype 4 were also made from horses kept adjacent to the insect collecting sites. this work presents the first definitive identification o ...19902209746
an indirect sandwich elisa utilising f(ab')2 fragments for the detection of african horsesickness virus.african horsesickness virus (ahsv), an important disease of equines is caused by an orbivirus. because of the need to contain the spread of the disease, it is often essential to make a rapid diagnosis. for this purpose, an elisa capable of detecting viral antigen in animal tissue and in cell culture fluid was developed. immobilised f(ab')2 fragments prepared by digestion of ahsv-specific igg with pepsin were used to trap virus from tissue homogenates or cell culture supernatant. after addition o ...19902266146
characterization and cloning of the african horsesickness virus genome.the dsrna profiles of all nine african horsesickness virus (ahsv) serotypes were compared by agarose gel electrophoresis and page. the agarose profiles were identical, but a unique profile was obtained for each of the nine serotypes by page. nine of the 10 dsrna genome segments of ahsv-3 were cloned and the clones were used in dot-spot and northern blot hybridization experiments to determine intra- and inter-serogroup nucleic acid similarities. segments 1, 3, 4, 5, 7 and 8 were highly conserved ...19902324709
the characterization of equine encephalosis virus and the development of genomic probes.equine encephalosis virus (eev) is an orbivirus associated with a peracute illness of horses in southern africa. the virus has now been partially purified for the first time and characterized on a molecular level. the virion is composed of 10 dsrna segments and a protein capsid consisting of at least seven structural proteins that vary in mr from 36,000 to 120,000. partial clones of six of the dsrna segments of eev serotype cascara were obtained and analysed for possible use as serotype-specific ...19892549180
characterization of a nonstructural phosphoprotein of two orbiviruses.a phosphorylated nonstructural protein, ns2, was detected in bluetongue and african horsesickness virus (btv and ahsv) infected-radiolabeled-cell lysates by electrophoresis on sds-polyacrylamide gels (sds-page). the ns2 proteins of both viruses have similar migration on one-dimensional (1d) 10% sds-page. examination of infected cell lysates on two-dimensional (2d) gels (isoelectric focusing followed by sds-page) separated two phosphorylated isoelectric forms of btv ns2 and four phosphorylated fo ...19882849253
bluetongue and related orbiviruses: overview of the world is silently spreading in tropical and subtropical countries in the world. serological surveys on bt in developing countries should be intensified and expanded. research is needed to develop simplified virus typing techniques, to develop safe and effective vaccines and to establish procedures for differentiating btv which produces clinical disease from that of low-virulency. it is considered necessary to develop a new disease reporting system which can accommodate both clinical and sub-clinica ...19852989847
gamma ray sensitivity of bluetongue, ehd and african horsesickness viruses and their precipitating and complement fixing antigens. 19852989879
sequence analyses of herpesviral enzymes suggest an ancient origin for human sexual behavior.comparison of the amino acid sequences of the deoxythymidine kinases of herpes simplex (hsv) and of marmoset herpes viruses (mhv) suggests a divergence time of 8 to 10 million years ago for hsv-1 and -2. like mhv, hsv-1 and -2 cause local infections in their natural hosts, and direct contact between two individuals during the brief period of infectivity is needed for transmission. because b virus, a nearer relative of hsv, depends on both oral and genital routes of transmission, we postulate tha ...19883128793
african horse sickness in zimbabwe: 1972 to 1981.during the nine years from october 1972 to september 1981 african horse sickness (ahs) virus was isolated from 23 suspected cases of the disease in zimbabwe and complement fixation antibody titres indicative of recent infection were detected in a further 49 horses. the 23 isolations belonged to seven of the nine known serotypes of ahs virus. in response to a questionnaire in 1980 the owners of 20% (1,654/8,000) of the horses in zimbabwe indicated that they had recorded 207 cases of clinically di ...19883194977
observations on antibody levels associated with active and passive immunity to african horse sickness.tests for neutralising (nt) antibodies to the nine serotypes of african horse sickness (ahs) virus on the sera of three groups of horses confirmed that an increasing number of immunisations with vaccine containing attenuated strains of serotypes 1 to 6 of the virus, leads to broader response to the various serotypes and to higher individual titres. nevertheless some horses failed to respond to one or more serotypes despite receiving numerous immunisations and it was clear that vaccine containing ...19883238767
[various aspects of horse sickness].the aetiology, symptoms, diagnosis and control of african horse sickness are described. special attention is paid to the introduction and epizootiology of the disease in spain and its consequences in respect to the international trade of horses.19883413759
a single dilution enzyme-linked immunosorbent assay for the quantitative detection of antibodies to african horsesickness virus.a single dilution enzyme-linked immunosorbent assay (elisa), utilizing a reference serum with a known, predetermined end-titre was used to compute antibody titres of serum samples against african horsesickness virus. compared to the complement fixation test it was found to be highly reproducible and sensitive. the assay also reduced the effect of between-test variations on test results and proved superior to an existing single-dilution elisa method.19873587930
role of culex pipiens l. in recovering latent african-horse-sickness virus from dogs. 19863722893
growth and persistent infection of african horse-sickness virus in a mosquito cell line. 19704097067
characterization of african horsesickness virus. 19704193496
studies on the replication of african horse-sickness virus in two different cell line cultures. 19674232530
detection of african horsesickness viral antigens in tissues by immunofluorescence.the fluorescent antibody reaction was studied in tissues of ponies infected with african horsesickness virus (ahsv). lung, spleen, lymph node, liver, skeletal muscle, intestine, stomach, nerve ganglion and kidney were sectioned and stained by the direct fluorescent antibody technique (fa). fluorescence was demonstrated only in the spleen and could be inhibited by using unconjugated antiserum.19724259931
african horse sickness virus antibodies in cyprus--1971-72. 19744428592
the isolation and identification of type 9 african horse sickness virus in the sudan. 19744447879
studies on the properties of african horse-sickness virus. 19684871753
cytology of monkey kidney cells infected with african horse-sickness virus. 19654953803
development of plaque techniques for titration and neutralization tests with african horse-sickness virus. 19664958049
sequential cellular changes produced by african horse-sickness virus in monkey kidney cells. 19664959956
some properties of avirulent cold variants of african horse sickness virus. 19674962856
buoyant density of african horsesickness virus. 19674964239
cytochemical studies with african horse sickness virus by fluorescent microscopy. 19674970515
thermal stability of african horse sickness virus. 19674970516
electron microscopic study of the formation of african horse-sickness virus. 19674971395
effects of freezing on african horse-sickness virus. 19684974541
quantitative studies on the neutralization reaction between african horse-sickness virus and antiserum. 19684977764
electron microscopic characterization of african horse-sickness virus. 19694978807
intracellular inclusions resulting from infection with african horsesickness virus.intranuclear and intracytoplasmic inclusions in monkey kidney cells infected with african horsesickness virus were studied with the aid of electron microscopy.19694980070
plaque formation by african horsesickness virus and characterization of its rna. 19705005083
isolation and identification of african horse-sickness virus in nigeria. 19715105172
the nucleic acid of african horse sickness virus. 19665223428
inactivated african horse sickness virus cell culture vaccine. 19685635756
infection of israeli culicoides with african horse sickness, blue tongue and akabane viruses.type 9 african horse sickness virus and type 4 bluetongue virus multiplied to a high titre in an israeli strain of culicoides puncticollis after intrathoracic inoculation. akabane virus persisted for at least 10 days in this midge after intrathoracic inoculation but with little evidence of virus multiplication. all 3 viruses failed to multiply in c. puncticollis after ingestion by the oral route and all were inactivated by 4 days post infection. five other species of israeli culicoides supported ...19816120643
antibody titres to african horse sickness, swine vesicular disease and foot-and-mouth disease viruses in samples from equidae in malta, 1975. 19826284298
the effect of temperature on the in vitro transcriptase reaction of bluetongue virus, epizootic haemorrhagic disease virus and african horsesickness virus.virions of bluetongue virus (btv), epizootic haemorrhagic disease virus (ehdv) and african horsesickness virus (ahsv) can be converted to core particles by treatment with chymotrypsin and magnesium. the conversion is characterized by the removal of the 2 outer capsid polypeptides of the virion. the loss of these 2 proteins results in an increase in density from 1,36 g/ml to 1,40 g/ml on cscl gradients. the btv, ehdv and ahsv core particles have an associated double-stranded rna dependent rna tra ...19826308533
factors associated with improved haemagglutination by african horse sickness virus. 19827112896
the incidence of african horse sickness antibodies in animals of various species in egypt. 19817201860
persistence of african horse sickness in nigeria. 19817292615
isolation and identification of african horsesickness virus from naturally infected dogs in upper egypt.african horsesickness virus was isolated from blood samples of street dogs in aswan province in arab republic of egypt. of six isolated "dog strain" african horsesickness viruses, three viruses designated d2, d6 and d10 have been identified as type 9 african horsesickness virus. methods of isolation, tissue culture adaptation, serological indentification and typing are described. horses experimentally infected with dog viruses showed febrile reaction and characteristic clinical and pathological ...19817337871
an outbreak of african horsesickness in dogs.several dogs died from african horsesickness which was contracted by the consumption of uncooked meat from the carcase of a horse that had died from the disease. respiratory embarrassment was the main clinical sign, while marked hydrothorax and pulmonary congestion and oedema were the major post mortem findings. serotype 6 horsesickness virus was isolated from 2 of these dogs.19817341783
the role played by hyalomma dromedarii in the transmission of african horse sickness virus in egypt. 19817348587
detection of african horse sickness viruses by dot-blot hybridization using a digoxigenin-labelled order to develop a non-radioactive dot-blot hybridization assay, for the detection of african-horse sickness virus (ahsv), genome segment 7 from 9 serotypes was amplified by rt-pcr. the resulting pcr products were denatured, immobilized on nylon membranes and then hybridized to a non-radioactive digoxigenin-labelled probe. this probe (265 bp in length) was generated by nested-pcr using genome segment 7 of ahsv, serotype 4 as a template. the dot-blot was visualized by chemiluminescence. positi ...19957477018
sequences of e/ns1 gene junction from four dengue-2 viruses of northeastern thailand and their evolutionary relationships with other dengue-2 viruses.we determined the 240-nucleotide sequences of the e/ns1 gene junction of four dengue-2 viruses by the primer extension dideoxy chain termination method. these viruses were isolated from dengue patients with different clinical severities in nakhon phanom, northeastern thailand in 1993. the results were compared with the 52 published dengue-2 sequences of the same gene region. sequence divergence of four new isolates varied from 4.17% to 5.42% compared with dengue-2 prototype new guinea c strain w ...19957494497
the virtual absence of culicoides imicola (diptera: ceratopogonidae) in a light-trap survey of the colder, high-lying area of the eastern orange free state, south africa, and implications for the transmission of arboviruses.altogether 52 078 culicoides biting midges of 35 species were collected during february 1990 and 1993 in 40 light-trap collections made on 17 cattle and/or sheep farms in the bethlehem and fouriesburg districts of the colder, high-lying eastern orange free state. culicoides (avaritia) bolitinos was by far the most abundant species, representing 50.9% of all specimens collected. culicoides (a.) imicola, considered to be the most common stock-associated species in the summer rainfall areas of sout ...19947501364
epidemiology of african horsesickness: duration of viraemia in zebra (equus burchelli).the viraemic period of african horsesickness is significantly longer in experimentally infected zebra than in horses. the virus could be isolated 40 d post-infection from blood and 48 d post-infection from spleen. the introduction of zebra into african horsesickness-free countries should therefore be considered carefully, and preferably be restricted to serologically negative zebra.19947501371
the multimeric nonstructural ns2 proteins of bluetongue virus, african horsesickness virus, and epizootic hemorrhagic disease virus differ in their single-stranded rna-binding ability.the structure and single-stranded (ss) rna-binding by the nonstructural protein ns2 of three different orbiviruses were studied and compared. african horsesickness virus (ahsv), bluetongue virus (btv), and epizootic hemorrhagic disease virus (ehdv) were analyzed in recombinant baculovirus-infected cells and in cells infected with btv and ahsv. sedimentation analysis and nonreducing sds-page revealed that ns2 of all three orbiviruses is a 7s multimer with both inter- and intramolecular disulfide ...19957539971
identification of a linear neutralization domain in the protein vp2 of african horse sickness virus.overlapping fragments of the outermost capsid protein vp2 of african horse sickness virus serotype 4 (ahsv-4) have been expressed in escherichia coli. horse sera from infected and vaccinated animals, rabbit sera, and mice monoclonal antibodies specific for ahsv were used to screen these fragments for antigenic regions. the screening revealed that the major antigenic domain of the ahsv-4 vp2 is localized in a central region (amino acids 200 to 413) and that both the n-terminal region (aa 1-159) a ...19957542417
application of the polymerase chain reaction to the detection of african horse sickness viruses.the development of a coupled reverse transcriptase-polymerase chain reaction assay (rt-pcr) is described for the detection of african horse sickness virus (ahsv) double-stranded rna. genome segments 7 and 10 were chosen as target templates for primers selected for use in the rt-pcr. using these ahsv-specific primers all 9 serotypes were detectable. the sensitivity and specificity of the rt-pcr results were compared to those obtained by competition elisa.19957543488
influence of antigen presentation and exogenous cytokine activity during in vitro primary immunizations employed for the generation of monoclonal antibodies.hybridomas secreting monoclonal antibodies (mabs) against african horse sickness virus (ahsv) were generated using different ahsv antigen preparations (inactivated ahsv, semi-purified virus, and a preparation of nonstructural viral proteins) in one of three different in vitro primary immunization systems: (i) the cel-prime kit, a method using immunization of splenocytes aided by antigen-primed support cells; (ii) a system based on a cytokine soup derived from a mixed lymphocyte reaction plus sti ...19957594620
proteolytic cleavage of vp2, an outer capsid protein of african horse sickness virus, by species-specific serum proteases enhances infectivity in culicoides.purified african horse sickness virus (ahsv) was fed, as part of a blood meal, to adult females from a susceptible colony of culicoides variipennis, established in the insectories at the institute for animal health, pirbright laboratory, uk. the meal consisted of heparinized blood obtained from ovine, bovine, equine (horse and donkey) or canine sources spiked with ahsv serotype 9 (ahsv9). the infectivity levels observed for c. variipennis varied significantly, according to the source of the bloo ...19957595366
african horsesickness epidemiology: five species of culicoides (diptera: ceratopogonidae) collected live behind the ears and at the dung of the african elephant in the kruger national park, south africa.during the culling of elephants (loxodonta africana) at five sites in the kruger national park, south africa, a total of 682 culicoides of five species of the subgenus avaritia were found live either behind the ears of elephants or attracted to the freshly disembowelled intestinal dung of elephants. the species are culicoides tororoensis khamala & kettle, 1971; c. kanagai khamala & kettle, 1971; c. loxodontis meiswinkel, 1992, and two undescribed species, i.e. culicoides sp. #50 and culicoides s ...19947596566
Displaying items 1 - 100 of 424