| prevalence of hepatitis virus and some arbovirus infections in kavango, northern swa/namibia. | a survey of the frequency of hepatitis b markers in 258 subjects from kavango, northern south west africa/namibia, was undertaken during february - may 1983. the hepatitis b surface antigen and hepatitis b e antigen carrier rates were 13,6% and 2,7% respectively. only 1,9% of the subjects were negative for all the markers tested, indicating that infection had been present at some stage in 98,1% of the sample. no known transmission method of the virus seems to fit this high exposure rate. the pos ... | 1985 | 3983734 |
| vector competence of senegalese aedes fowleri (diptera: culicidae) for rift valley fever virus. | | 1988 | 3404545 |
| rift valley fever in egypt 1986. surveillance of sheep flocks grazing in the northeast nile delta. | from october 1985 through november 1986, 1714 presumably unvaccinated sheep in 13 nomadic flocks located in four provinces in dakahliya governorate, in the northeast nile delta, were ear tagged and monitored for acquisition of rift valley fever virus (rvfv) antibodies. sheep were bled at approximately 3 month intervals and sera were tested for haemagglutination inhibition (hi) antibodies to rvfv. hi reactors were tested for rvfv specific igm antibody by enzyme-linked immunosorbent assay (elisa) ... | 1988 | 3404565 |
| the distribution of rift valley fever virus in the mosquito culex pipiens as revealed by viral titration of dissected organs and tissues. | distribution of rift valley fever virus (rvfv) was studied in the mosquito culex pipiens. mosquitoes were dissected on days 1-7 after an infectious bloodmeal, and rvfv plaque assays were performed on the legs, posterior midgut, ovaries, salivary glands, thoracic ganglia, and remaining organs and tissues (remnants). on days 7-12 and 14 following an infectious bloodmeal, mosquitoes were tested for their ability to transmit virus and then dissected. dissemination (systemic infection) rates averaged ... | 1988 | 3407841 |
| viral haemorrhagic fever survey in chobe (botswana). | | 1987 | 3445357 |
| pathogenesis of rift valley fever virus (rvfv) in inbred rats. | the pathogenesis of rift valley fever in adult rats from 3 inbred strains (lew, maxx, wf) was investigated. wf rats all died by day 2 postinoculation with viral tissue titers reaching 9 log10 pfu/g. lew and maxx rats were resistant to liver disease, but fatal necrotising encephalitis developed in 16 and 44% of the rats, respectively. detection of serum neutralising antibody on day 3 coincided with clearance of virus from serum and liver, although infectious virus was detected in spleen homogenat ... | 1987 | 3509859 |
| evaluation of a new rift valley fever vaccine: safety and immunogenicity trials. | a formalin-inactivated rift valley fever vaccine prepared in primary monkey kidney cells has been used to protect laboratory workers from disease since 1967. a similar but improved vaccine was prepared in 1978-1979 using well characterized diploid fetal rhesus lung cells. in initial clinical trials reported here, the new vaccine elicited high levels of plaque neutralizing antibodies and caused only minimal local reactions at the injection site. significant variability was observed in the geometr ... | 1986 | 3532605 |
| vector competence tests with rift valley fever virus and five south african species of mosquito. | aedes juppi was readily infected by inoculation with virus but failed to transmit either horizontally or vertically. seventy-five to 90% of the other 4 mosquito species became infected after ingesting 6.8-9.8 log10cpd50/ml of virus. these species all transmitted virus at the following rates on the post-infection days indicated: aedes unidentatus (58%--day 11), aedes dentatus (32%--day 11, 50%--day 18), culex poicilipes (15%--day 15, 80%--day 30) and aedes argenteopunctatus (14% on day 30). on th ... | 1988 | 2903903 |
| mutagen-directed attenuation of rift valley fever virus as a method for vaccine development. | serial mutagenesis with 5-fluorouracil has been employed to derive an attenuated strain of rift valley fever virus for use as a live virus vaccine. | 1985 | 4045430 |
| isolation of rift valley fever virus from cattle abortions in tanzania. | | 1985 | 4060243 |
| rift valley fever. 2. attempts to transmit virus with seven species of mosquito. | | 1973 | 4148061 |
| rift valley fever. 3. viraemia in cattle and sheep. 4. the susceptibility of mice and hamsters in relation to transmission of virus by mosquitoes. | | 1973 | 4149110 |
| selection of avirulent variants of rift valley fever virus. | | 1974 | 4465474 |
| the pathogenicity of rift valley fever virus for the baboon. | | 1972 | 4558832 |
| fluorescent and neutralizing antibody response to infection by rift valley fever virus. | | 1973 | 4588885 |
| induction of virus-inhibiting factor or interferon in mice by strains with different virulence of rift valley fever virus. | | 1972 | 4632205 |
| long term existence of rift valley fever virus in immune mice. | | 1973 | 4805358 |
| immunofluorescent cell-counting assay of rift valley fever virus. | | 1969 | 4893388 |
| detection of rift valley fever virus by the fluorescent antibody technique in organs of experimentally infected animals. | | 1970 | 4926635 |
| heat- and acid-labile virus-inhibiting factor or interferon induced by rift valley fever virus in mice. | | 1971 | 5003260 |
| susceptibility of dogs and cats to rift valley fever by inhalation or ingestion of virus. | | 1972 | 5016294 |
| ultrafiltration as a method for concentrating rift valley fever virus grown in tissue culture. | filtration by means of a diaflo ultrafilter was used to concentrate three 1,000-ml lots and one 3,000-ml lot of tissue culture-grown rift valley fever virus. quantitation of both infectivity and total protein was achieved. water treatment with continued ultrafiltration of the virus concentrate provided a final virus product approximately 99.25% free of low-molecular-weight materials originally present in the growth medium. | 1971 | 5103483 |
| the clinical aspects of rift valley fever virus in household pets. i. susceptibility of the dog. | | 1970 | 5410787 |
| relationship between plaque assay and the mouse assay for titrating rift valley fever virus. | | 1970 | 5457747 |
| the clinical aspects of rift valley fever virus in household pets. ii. susceptibility of the cat. | | 1970 | 5460684 |
| the clinical aspects of rift valley fever virus in household pets. 3. pathologic changes in the dog and cat. | | 1970 | 5460685 |
| concentration of rift valley fever and chikungunya viruses by precipitation. | simple and efficient methods for concentrating rift valley fever (rvf) virus and chikungunya (chik) virus are described. ammonium sulfate, potassium sulfate, or alcohol was used as a precipitating agent and the precipitate was resuspended to volumes suitable for further processing and purification. the methods permitted concentration of live rvf virus and chik virus about 100-fold with negligible losses of virus. rvf virus retained a high level of infectivity with potassium aluminum sulfate and ... | 1970 | 5494763 |
| electron microscopic studies on bhk 21 cells infected with rift valley fever virus. | | 1968 | 5729635 |
| growth of rift valley fever virus in human diploid (wi-38) cells. | | 1969 | 5766737 |
| interacting factors that influence long-term storage of live pasteurella tularensis vaccine and rift valley fever virus. | studies were conducted on the interaction of various parameters which affect the storage stability and growth potential of liquid cultures of pasteurella tularensis live vaccine strain (lvs) and rift valley fever virus van wyk strain (rvfv). storage variables studied with lvs included four storage temperatures (4, -20, -65, -175 c), single and multiple freeze-thaw cycles, two freezing and two thawing rates (slow and fast), various inoculum levels (1, 3, 5, and 10%) for the determination of growt ... | 1969 | 5780399 |
| evaluation of factors related to growth of rift valley fever virus in suspended cell cultures. | the effect of several controlled variables on the peak titer and fold increase of rift valley fever virus grown in suspension culture on two variants of earle's l cell, l-dr and l-ma clone 1-1, was studied. no significant amount of cell-associated virus was found at 24 hr, indicating a release of virus soon after its formation. mild sonic treatment of the virus produced in serum-free medium increased the infective titer about 10x. this difference was not observed with virus produced in medium su ... | 1969 | 5814993 |
| stability of rift valley fever virus at 4 c. | | 1967 | 6029841 |
| complete sequences of the glycoproteins and m rna of punta toro phlebovirus compared to those of rift valley fever virus. | the complete sequence of punta toro virus (phlebovirus, bunyaviridae) middle size (m), rna has been determined. the rna is 4330 nucleotides long (mol wt 1.46 x 10(6), base composition: 26.7% a, 33.6% u, 18.5% g, 21.2% c) and has 3'- and 5'-terminal sequences that, depending on the arrangement, are complementary for some 15 residues. the viral rna codes in its viral-complementary sequence for a single primary gene product (the viral glycoprotein precursor) that is comprised of 1313 amino acids (1 ... | 1985 | 2998043 |
| experimental infection of cattle with pantropic rift valley fever virus. | | 1967 | 6064502 |
| biological characteristics of plaque variants of rift valley fever virus. | | 1967 | 6070948 |
| serological relation between rift valley fever virus and viruses of phlebotomus fever serogroup. | | 1980 | 6103252 |
| vector studies on rift valley fever virus in south africa. | | 1980 | 6105722 |
| pathogenicity and immunogenicity of a mutagen-attenuated rift valley fever virus immunogen in pregnant ewes. | a mutagenized clone of rift valley fever virus (rvfv; mv p12) used in inoculation of 3 pregnant ewes was immunogenic, nonpathogenic, and nonabortogenic. in contrast, inoculation of a matched group of 3 pregnant ewes with parent rvfv induced clinical disease and abortions. ewes given mv p12 delivered healthy lambs that had rvfv antibody titers of less than 1:10 at birth, increasing to greater than or equal to 1:80 after ingestion of colostrum. ewes inoculated with parent rvfv developed marked vir ... | 1987 | 3631685 |
| enzyme-linked immunosorbent assay for detection of antibodies to rift valley fever virus in ovine and bovine sera. | an enzyme-linked immunosorbent assay (elisa) was developed for the rapid detection of antibodies to rift valley fever virus (rvfv) in ovine and bovine sera. conditions to reduce nonspecific reactions were optimized. the elisa results correlated with those of a plaque-reduction neutralization test, revealing 100% specificity and 90.7% sensitivity. in sera from sheep and cattle inoculated against rvfv, the hemagglutination-inhibition test in combination with the elisa provided a better indication ... | 1987 | 3631700 |
| recombinant dna technology for the preparation of subunit vaccines. | recombinant dna technology appears to be on the verge of producing safe and effective protein vaccines for animal and human diseases. the procedure is applicable to most viruses because their isolated surface proteins generally possess immunogenic activity. strategies used for the preparation and cloning of the appropriate genes depend on the characteristics of the viral genomes: whether dna or rna; their size, strandedness, and segmentation; and whether messenger rna are monocistronic or polyci ... | 1982 | 6129235 |
| monoclonal antibodies to identify zinga virus as rift valley fever virus. | | 1983 | 6131312 |
| reduced survival of adult culex pipiens infected with rift valley fever virus. | the effect of rift valley fever (rvf) viral infection on the survival of female culex pipiens was examined. in 3 experiments in which mosquitoes ingested rvf virus, there was a 44% decrease in survival to days 14-16 for transmitting vs. nontransmitting mosquitoes, and a 48% decrease in survival for individuals with disseminated vs. nondisseminated infections. these results were corroborated by other experiments in which survival of mosquitoes intrathoracically inoculated with rvf virus was compa ... | 1987 | 3661832 |
| serological evidence of endemic zinga virus and rift valley fever virus in central african republic. | | 1983 | 6134127 |
| isolation of crimean-congo haemorrhagic fever and rift valley fever viruses in upper volta. | | 1984 | 6144896 |
| [rift valley fever]. | | 1984 | 6145273 |
| increased mosquito feeding on rift valley fever virus-infected lambs. | experiments were conducted to determine whether or not mosquitoes exhibited an increase in feeding on rift valley fever (rvf) virus-infected lambs as compared to uninfected ones. overall, when given a choice between a viremic lamb, or its uninfected twin, 65% (1,264/1,943) of the engorged female culex pipiens obtained blood from the viremic lamb. this excess of feedings on viremic lambs was demonstrated regardless of the age of the lambs, or the time period between inoculation of the lambs and e ... | 1984 | 6150656 |
| rift valley fever: a sero-epidemiological survey among pregnant women in mozambique. | rift valley fever (rvf) causes abortion in sheep and cattle. however, the teratogenic and abortogenic potential of rvf in humans is not known. sera from a total of 1163 pregnant women in mozambique were tested for rvf virus antibodies by elisa and 28 (2%) were found to be positive. mothers experiencing fetal death or miscarriage (155) had the same rvf virus antibody prevalence as those with normal deliveries. analysis of maternity histories showed some indication of increased fetal wastage among ... | 1987 | 3678406 |
| experimental infection and protection of lambs with a minute plaque variant of rift valley fever virus. | the injection of a single dose containing 5 x 10(3) plaque forming units (pfu) of a minute plaque variant of rift valley fever virus (rvfv) into two susceptible lambs resulted in no detectable viremia, pyrexia or clinical signs of disease. immunization with the minute plaque variant induced neutralizing antibody as early as seven days postinoculation; however, no complement fixing antibodies were detected. lambs immunized in this manner were protected when challenged with an infectious dose cont ... | 1986 | 3706629 |
| [recent research progress on interferon]. | | 1982 | 6180965 |
| rift valley fever surveillance in mobile sheep flocks in the nile delta. | rift valley fever (rvf) surveillance was carried out in the nile delta by monitoring mobile and stationary sheep flocks for antibodies to rvf virus. sheep are known to be susceptible to rvf virus infection and experienced severe morbidity in 1977 and 1978 when rvf was epidemic in egypt. four hundred six sheep in 32 flocks were surveyed during 1984. twenty-four sheep from 7 flocks had antibodies to rvf virus detected by hemagglutination inhibition and plaque reduction neutralization tests. antibo ... | 1986 | 3766852 |
| effect of extrinsic incubation temperature on the ability of aedes taeniorhynchus and culex pipiens to transmit rift valley fever virus. | studies were conducted to examine the effects of extrinsic incubation (ei) temperature on the vector competence of egyptian culex pipiens and north american aedes taeniorhynchus for rift valley fever (rvf) virus. following per os exposure, infection rates in ae. taeniorhynchus remained relatively constant at 55%, 56%, and 59% for mosquitoes held at ei temperatures of 13, 26, and 33 degrees c, respectively. in contrast, significantly fewer cx. pipiens became infected when held at 13 degrees c (38 ... | 1985 | 3834803 |
| clinical and pathological studies in adult sheep and goats experimentally infected with wesselsbron disease virus. | the clinical symptoms and pathology in 33 adult sheep and 31 adult goats experimentally infected with wesselsbron disease virus are described. there was moderate to severe hyperthermia in most animals, but no other clinical signs of disease or deaths were recorded. eleven sheep and 6 goats were sacrificed for pathological studies at various stages during the febrile response. the macroscopic and microscopic lesions in these cases are described. microscopic studies revealed that the liver was con ... | 1982 | 6289220 |
| antiviral efficacy of pyrazofurin against selected rna viruses. | the antibiotic pyrazofurin, 3-(beta-d-ribofuranosyl)-4-hydroxypyrazole-5-carboxamide, markedly inhibited the in vitro replication of a number of rna viruses including rift valley fever (rvf), venezuelan equine encephalomyelitis (vee), sandfly, pichinde, lassa and lcm virus. plaque formation was reduced by 80% or more with 2-10 micrograms/ml of pyrazofurin while 2 micrograms/ml reduced by 1000-fold the yield of lassa and lcm virus in a yield reduction assay. in vivo, pyrazofurin failed to protect ... | 1982 | 6299188 |
| characterization of eight new phlebotomus fever serogroup arboviruses (bunyaviridae: phlebovirus) from the amazon region of brazil. | eight new members of the phlebotomus fever arbovirus serogroup (family bunyaviridae; genus phlebovirus) from the amazon region of brazil are described. one serotype was recovered from a febrile patient, three from small wild animals and four from sand flies. a small serum survey carried out with the human isolate, alenquer virus, suggests that it rarely infects man. complement-fixation and plaque reduction neutralization tests were done, comparing the eight new viruses with other members of the ... | 1983 | 6312820 |
| rift valley fever. | | 1983 | 6359835 |
| enhanced mosquito blood-finding success on parasitemic hosts: evidence for vector-parasite mutualism. | the generalized hematopathology frequently found in animals infected with vector-borne pathogens may maximize transmission by enhancing the ability of vectors to locate blood in infected hosts. we tested this idea of mutualism between parasite and vector by comparing duration of probing of mosquitoes feeding on noninfected and on malaria-(plasmodium chabaudi) or arbovirus-(rift valley fever virus) infected animals. we found that median duration of probing (blood location) on infected rodents was ... | 1985 | 3865192 |
| rainfall and epizootic rift valley fever. | epizootic rift valley fever (rvf) has occurred in kenya four times over the last 30 years. widespread, frequent, and persistent rainfall has been a feature of these epizootic periods. a composite statistic, based upon measurements of these rainfall characteristics, is positive during periods of epizootic rift valley fever. the heavy rainfall raises the level of the water table in certain areas, flooding the grassland depressions (dambos) that are the habitat of the immature forms of certain grou ... | 1985 | 3879206 |
| detection of rift valley fever virus antigen by enzyme-linked immunosorbent assay. | a double-antibody (sandwich) enzyme-linked immunosorbent assay (elisa) was adapted to detect rift valley fever virus antigen. antibodies were purified from hyperimmune mouse and rabbit sera by affinity chromatography, using cnbr-activated sepharose 4b coupled to a beta-propiolactone-inactivated sucrose-acetone-extracted suckling mouse liver antigen. in the assay, antigen was captured by mouse antibody adsorbed to polystyrene plates and then detected by reacting sequentially with rabbit anti-rift ... | 1983 | 6409920 |
| investigations following initial recognition of crimean-congo haemorrhagic fever in south africa and the diagnosis of 2 further cases. | sera from 124 cattle herds were tested, and antibodies to crimean-congo haemorrhagic fever (cchf) were found in 93 herds. the prevalence of antibodies was high in the interior of the country, in excess of 90% in some herds, but was less than 4% in cattle along the coast from cape town to east london. only 17 out of 1109 (1,5%) human residents of 55 farms had antibodies to cchf, while none of 164 veterinary research workers or 98 veterinarians engaged in farm animal practice had them. specimens f ... | 1985 | 3933132 |
| messenger rna of the m segment rna of rift valley fever virus. | the putative messenger rna (mrna) of the m segment rna of the phlebovirus rift valley fever virus (rvfv) has been characterized using s1 nuclease mapping and oligonucleotide primer extension procedures. these experiments revealed that the 3' end of the mrna lacks approximately 112 nucleotides of the m genomic rna sequences, and that the 5' end of the mrna possesses all of the sequences present at the 3' end of the m rna but is further extended beyond the end of the genome by some 12-14 nucleotid ... | 1986 | 3962188 |
| active and passive immunization against rift valley fever virus infection in syrian hamsters. | the protection by active and passive immunization of golden syrian hamsters challenged with rift valley fever (rvf) virus intraperitoneally was studied. six groups of 10 hamsters were inoculated with different amounts of immune serum while five groups were actively immunized with different doses of a formalin-inactivated rvf vaccine. one day after passive and three weeks after active immunization all hamsters were challenged with 5000 plaque-forming units of rvf virus. plaque reduction neutraliz ... | 1984 | 6507105 |
| preliminary survey of domestic animals of the sudan for precipitating antibodies to rift valley fever virus. | in a preliminary seroepidemiological survey a total of 780 serum samples derived from various domestic animals of the sudan were examined for rift valley fever (rvf) virus precipitating antibodies. the incidence was approximately 34.3% in sheep, 33.2% in cattle, 22% in goats, 7.9% in camels and 4% in donkeys. the findings indicated that rvf is mainly prevalent in the rich savanna areas of the south as well as the irrigated areas close to the nile in the north. circumstantial evidence suggests th ... | 1984 | 6512261 |
| [rift valley fever and zinga virus: a pathogenic arbovirus in man and animal new for madagascar]. | virus zinga strains have been isolated from several pools of mosquitoes collected in perinet area, 130 km far from tananarive, at the institut pasteur of madagascar in 1980. although this virus is pathogenic for man, it seemed to give only a mild illness and did not appear to constitute a problem of public health. but today it is seen in quite a different way; since the who center for arbovirus reference and research of new haven has shown the serologic identity between virus zinga and an anothe ... | 1984 | 6534285 |
| detection of human immunoglobulins g and m antibodies to rift valley fever virus by enzyme-linked immunosorbent assay. | rift valley fever virus (rvfv) is an important human and animal pathogen in africa and has been responsible for infections in travelers. because of the aerosol infectivity and risk of dissemination of the virus, a need exists for simple, safe, serological tests for diagnosis. an enzyme-linked immunosorbent assay (elisa) was developed to detect rvfv-specific immunoglobulins (immunoglobulin g [igg] and igm). in the test, a betapropiolactone-inactivated, sucrose-acetone-extracted, suckling mouse li ... | 1984 | 6538206 |
| mechanical transmission of rift valley fever virus by hematophagous diptera. | experimental studies were conducted to determine if hematophagous diptera were capable of mechanical transmission of rift valley fever (rvf) virus to laboratory animals. all species tested (glossina morsitans, aedes aegypti, aedes taeniorhynchus, culex pipiens, stomoxys calcitrans, lutzomyia longipalpis, and culicoides variipennis) mechanically transmitted the virus to hamsters. mechanical transmission rates for g. morsitans ranged from 0-100%, with the probability of mechanical transmission pos ... | 1985 | 3970308 |
| the use of veterinary vaccines for prevention and control of rift valley fever: memorandum from a who/fao meeting. | this memorandum considers the use of veterinary vaccines for the prevention of rift valley fever (rvf) and for its control during outbreaks. veterinary vaccines are the first line of defence against rvf. existing live and inactivated vaccines have been used extensively in africa but further development of both is warranted. the live virus vaccine may cause abortion and its potential for reversion to virulence has not been adequately investigated. it should be used only in enzootic and epizootic ... | 1983 | 6602663 |
| enzyme-linked immunosorbent assay for detection of rift valley fever virus antigen in mosquitoes. | an enzyme-linked immunosorbent assay (elisa) was used to measure the quantity of rift valley fever (rvf) viral antigen in infected egyptian culex pipiens. infectivity, as measured by plaque assay, was significantly correlated with viral antigen, as measured by the elisa, in all groups of mosquitoes regardless of the time interval after the infectious blood meal. the proportion of noninfectious viral antigen in these groups increased with time. when individual mosquitoes were assayed the plaque a ... | 1985 | 3985279 |
| broad-spectrum antiviral activity of 2-beta-d-ribofuranosylselenazole-4-carboxamide, a new antiviral agent. | the relative in vitro antiviral activities of three related nucleoside carboxamides, ribavirin (1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamide), tiazofurin (2-beta-d-ribofuranosylthiazole-4-carboxamide), and selenazole (2-beta-d-ribofuranosylselenazole-4-carboxamide), were studied against selected dna and rna viruses. although the activity of selenazole against different viruses varied, it was significantly more potent than ribavirin and tiazofurin against all tested representatives of the ... | 1983 | 6615611 |
| rift valley fever in kenya: the presence of antibody to the virus in camels (camelus dromedarius). | five hundred and seventy-one camel sera collected after an epizootic of rift valley fever were examined for antibody to the virus. clinical disease had not been observed in cattle and sheep in the ecosystems shared with the camels. positive sera with high titres of serum neutralizing antibody were found in 22% of camels at one of the seven sampling sites. | 1985 | 3989285 |
| culex pipiens (diptera: culicidae) morbidity and mortality associated with rift valley fever virus infection. | | 1985 | 4009630 |
| replication and dissemination of rift valley fever virus in culex pipiens. | following ingestion of 10(4.2) to 10(7.2) plaque-forming units (pfu) of rift valley fever (rvf) virus, 662 of 850 female culex pipiens (78%) became infected. those mosquitoes that became infected separated into two distinct groups: 1) those with a nondisseminated infection limited to the gut, and 2) those with a disseminated infection. the former group contained a median of 10(3.2) pfu, while those females with a disseminated infection contained a median of 10(5.5) pfu. only those females with a ... | 1984 | 6696176 |
| enhanced efficacy of liposome-encapsulated ribavirin against rift valley fever virus infection in mice. | administration of liposome-encapsulated ribavirin to mice led to ribavirin concentrations in the liver, the primary site of rift valley fever virus proliferation, that were fivefold greater than those attained with the same doses of free ribavirin. liposomal ribavirin given at a dose of either 25 or 50 mg of drug per kg of body weight protected mice against a rapidly lethal high-titer challenge with rift valley fever virus, whereas similar doses of free drug or empty liposomes had no detectable ... | 1985 | 4026264 |
| replication of rift valley fever virus in the sand fly lutzomyia longipalpis. | rift valley fever virus was shown to replicate in lutzomyia longipalpis after intrathoracic inoculation. viral titers peaked at approximately 4 days postinoculation [mean titer = 10(4.0) plaque forming units (pfu)] and remained relatively constant through day 7. a minimum of 6 of 326 sand flies transmitted virus by bite to susceptible hamsters after 5-9 days of extrinsic incubation. viral titers of sand flies exposed per os declined steadily through day 9. none of 378 flies that had ingested app ... | 1984 | 6711746 |
| adjuvant activity of a novel metabolizable lipid emulsion with inactivated viral vaccines. | studies were conducted in mice, hamsters, sheep, and two species of nonhuman primates which demonstrate the adjuvant activity of a new metabolizable lipid emulsion with marginally immunogenic doses of formalin-inactivated viral vaccines. the lipid base consists of highly refined peanut oil emulsified in aqueous vaccines with glycerol and lecithin. hamsters and mice inoculated with lipid emulsion plus western or venezuelan equine encephalitis vaccine were significantly more resistant than vaccina ... | 1980 | 6772571 |
| a rift valley fever vaccine trial: 2. serological response to booster doses with a comparison of intradermal versus subcutaneous injection. | a booster dose of a formalin-inactivated, cell culture-propagated rift valley fever vaccine (tsi-gsd-200) was administered without significant reactogenicity to 60 volunteers 18 months after they received a three dose primary series. blood was drawn for serological testing prior to boosting and 10, 49, and 180 days thereafter. neutralizing antibody response was prompt, being maximum on day 10 and considerably higher than the peak titres obtained on day 42 after the initial series. a marked decli ... | 1985 | 4036270 |
| a serological survey for rift valley fever antibody in food animals in kaduna and sokoto states of nigeria. | a total of 1106 serum samples from cattle, sheep, goats and camels were collected from kaduna and sokoto states of nigeria. these were tested for the presence of antibody to rift valley fever virus by the agar gel immunodiffusion method. the antibody prevalence rates were 2.85% in cattle, 6.67% in sheep, 0.98% in goats and 3.13% in camels. | 1982 | 6820360 |
| rift valley fever virus vaccine trial: study of neutralizing antibody response in humans. | the serological response to immunization with a formalin inactivated rift valley fever (rvf) vaccine was studied in 963 swedish un soldiers serving in the sinai peninsula. antibody titres were determined with a plaque reduction neutralization test (prnt). attempts were made to give all soldiers three injections (1 ml s.c. days 0, 7-10 and 28-30) but 128 soldiers received only two injections. in a group of 51 fully vaccinated individuals, repeated blood samples were collected. fifty of the vaccin ... | 1985 | 4036271 |
| rdb--a new product of plant origin for cell culture dispersion. | rdb is a crude preparation extracted from a plant source. it is a very potent agent for dispersion of monolayer cell cultures as well as for the preparation of primary cell suspensions. it was found to be most effective in dispersing a wide range of animal and mosquito cells and dissociating neuronal and muscular tissue for primary cell cultures. rdb was also found to be useful for preparation of primary culture for chick embryo fibroblasts. after treatment with rdb cell viability was found to b ... | 1985 | 4043538 |
| comparison of techniques for demonstrating antibodies to rift valley fever virus. | nine serological techniques were compared by monitoring the response to infection with rift valley fever (rvf) virus in three sheep. antibodies were monitored daily for the first 14 days after infection, then weekly and later fortnightly up to week 24. the earliest antibody response was detected in one sheep on day 3 by a plaque reduction neutralization test, and by day 6 antibodies were demonstrable in all three sheep by haemagglutination-inhibition, reversed passive haemagglutination-inhibitio ... | 1986 | 3537118 |
| comparative pathogenicity and antigenic cross-reactivity of rift valley fever and other african phleboviruses in sheep. | homologous and heterologous haemagglutination-inhibition (hai), complement-fixation (cf), immunodiffusion (id) and mouse neutralization tests were performed with the lunyo (lun) and a zimbabwean strain of rift valley fever (rvf) virus, the prototype and a south african strain of arumowot (amt) virus and prototype strains of gordil (gor), saint-floris (saf) and gabek forest (gf) viruses, using immune mouse ascitic fluids prepared against these viruses. reactions of identity occurred in all tests ... | 1986 | 3537119 |
| [current serologic data on viral hemorrhagic fevers in the central african republic]. | during the years 1984-1985, 1,528 serum samples were taken through out the car. of these sera, 319 (20.8%) contained anti-filoviridae antibodies (ebola, marburg). this figure is higher than those found in cameroon, sudan, gabon and zaïre. three zones of the country are particularly exposed, the north-east where the population is in the contact with sudan ebola, the south-east where it is in contact with zaïre ebola, and the south-west where it is in contact with sudan ebola. the authors believe ... | 1987 | 3607998 |
| effect of virus input multiplicity and tissue cell concentration on growth of rift valley fever virus. | the effects of virus input multiplicity and of tissue cell concentration upon the growth of rift valley fever virus in l cells (earle) were determined. the titers obtained in suspension cultures with cells obtained from two separate laboratories were significantly different. with both monolayer culture and suspension culture systems, a virus input multiplicity of 2.5 resulted in the greatest proliferation of virus. optimal viral yields were obtained in suspension cultures containing 4 x 10(5) ti ... | 1967 | 6035052 |
| rift valley fever, egypt 1977: disease spread by windborne insect vectors? | | 1982 | 7064329 |
| [isolation of rift valley fever virus from bats in the republic of guinea]. | virological investigations of bats performed in the territory of republic of guinea permitted for the first time to isolate from the bats micropteropus pusillus and hipposideros abae two strains which were identified as r. v. f. v. serological investigation revealed specific antibodies to r. v. f. v. among natives in 3.3% and among domestic animals in 6.8%. it is supposed that bats are reservoir of this virus. they can transmit agent of r. v. f. by means of mosquitoes or by being part of the nat ... | 1987 | 3607999 |
| identification of a major non-structural protein in the nuclei of rift valley fever virus-infected cells. | a non-structural protein of mol. wt. 34 x 10(3) was demonstrated in the nuclei of rift valley fever virus-infected vero cells by sds-polyacrylamide gel electro-phoresis. the protein appears to correspond to the virus-induced antigen demonstrated by indirect immunofluorescence in intranuclear inclusions. | 1982 | 7108491 |
| inbred rat strains mimic the disparate human response to rift valley fever virus infection. | | 1982 | 7130966 |
| [hematophagous diptera arbovirus vectors in africa (author's transl)]. | the authors, in a first part, show the general arthropods-viruses-vertebrates relationships and specially the different conditions of virus maintenance in the selvatic foci. then they succinctly give the main characteristics of the vectors bioecology useful for understanding the epidemiology of arbovirus diseases of man and domestic animals. thus diptera vectors of o'nyong-nyong and chikungunya fevers, yellow fever, dengue fever, wesselsbron, sindbis, and west nile viruses, rift valley fever, sa ... | 1981 | 6116145 |
| weather, host and vector--their interplay in the spread of insect-borne animal virus diseases. | the spread of insect-borne animal virus diseases is influenced by a number of factors. hosts migrate, move or are conveyed over long distances: vectors are carried on the wind for varying distances in search of hosts and breeding sites; weather and climate affect hosts and vectors through temperature, moisture and wind. as parasites of host and vector, viruses are carried by animals, birds and insects, and their spread can be correlated with the migration of hosts and the carriage of vectors on ... | 1980 | 6131919 |
| the susceptibility of culicoides variipennis coq. (diptera: ceratopogonidae) to laboratory infection with rift valley fever virus. | the vector potential of culicoides variipennis for rift valley fever virus (rvfv) was investigated. insects from a colony maintained at the animal virus research institute, pirbright, were fed through a membrane on a mixture of mouse blood and rvfv (virus concentration of blood meal 7 x 95 log10 mld50ml). engorged insects were maintained at 25 degrees c +/- 1 degrees c. samples of insects were tested at daily intervals to determine their virus content. four of the five females tested immediately ... | 1982 | 7179410 |
| inhibition of rna viruses in vitro and in rift valley fever-infected mice by didemnins a and b. | didemnins, a new class of depsipeptides isolated from a caribbean tunicate, have been shown to have potent antiviral activity against a broad range of rna viruses in vitro. didemnins a and b both protected mice against a lethal challenge of rift valley fever virus. | 1982 | 7188246 |
| synergistic antiviral effects of ribavirin and the c-nucleoside analogs tiazofurin and selenazofurin against togaviruses, bunyaviruses, and arenaviruses. | binary combinations of the n-nucleoside ribavirin (1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamide) and the c-nucleoside analog selenazofurin (2-beta-d-ribofuranosylselenazole-4-carboxamide) or tiazofurin (2-beta-d-ribofuranosylthiazole-4-carboxamide) were tested in vitro for activity against venezuelan equine encephalomyelitis, japanese encephalitis, yellow fever, rift valley fever, korean hemorrhagic fever, and pichinde viruses. the 50% effective dose for each compound alone or in a series ... | 1984 | 6151377 |
| studies on the antigenic relationship among phleboviruses. | | 1982 | 6174048 |
| in-vivo activity of antivirals against exotic rna viral infections. | infection of humans by viruses belonging to the families of toga-, bunya-, and arenaviridae constitutes a major health problem worldwide and certain of the viruses have the potential to cause widespread epidemics. in the search for effective chemotherapy against these viruses several hundred nucleoside and nucleotide analogues have been screened for antiviral activity. of the compounds tested, ribavirin, has been shown in laboratory animal models to have significant inhibitory effects against ri ... | 1984 | 6208183 |
| [brain teratology as a result of transplacental virus infection in ruminants]. | various viruses relating to congenital brain teratology in ruminants are discussed. these include: bluetongue which may be responsible for porencephaly and hydranencephaly; akabane disease, rift valley fever (mouse brain attenuated virus) and wesselsbron disease (wild-type and mouse brain attenuated viruses) which can give rise to porencephaly, hydranencephaly, micrencephaly and cerebellar hypoplasia, and bovine viral diarrhoea-mucosal disease which results only in cerebellar hypoplasia. certain ... | 1980 | 6267276 |
| rift valley fever retinitis. | a 57-year-old dutch woman, who had lived and worked in tanzania for 26 years, developed serious, progressive bilateral retinitis after suffering from a fever of unknown origin. fundus abnormalities in both eyes suggested that the woman had been infected with rift valley fever virus. serologic studies confirmed this suspicion. white macular lesions accompanied to extensive vasculitis appear to be specific for rift valley fever retinitis. | 1981 | 7196157 |
| zinga virus: a strain of rift valley fever virus. | | 1983 | 6403821 |
| reversed passive hemagglutination and inhibition with rift valley fever and crimean-congo hemorrhagic fever viruses. | reversed passive hemagglutination (rpha) tests were performed by coating glutaraldehyde-fixed and tannic acid-treated sheep erthrocytes with antibodies to rift valley fever (rvf) and crimean-congo hemorrhagic fever (cchf) viruses. cells coated with crude antibody, in the form of mouse immune ascitic fluid, reacted with high specificity and sensitivity in rpha tests with live or inactivated virus antigens. in inhibition (rphi) tests, rvf antibody titers in human and sheep sera were similar to tho ... | 1983 | 6407347 |
| rift valley fever virus vaccine trial: study of side-effects in humans. | | 1982 | 7201671 |
| the extended horizons of rift valley fever: current and projected immunogens. | | 1980 | 7208510 |
| antibodies against haemorrhagic fever viruses in kenya populations. | human sera from lodwar (77 sera), nzoia (841 sera), masinga (251 sera), laisamis (174 sera) and the malindi/kilifi area (556 sera) in kenya were tested by indirect immunofluorescence for antibodies against marburg, ebola (zaire and sudan strains), congo haemorrhagic fever, rift valley fever and lassa viruses. antibodies against ebola virus, particularly the zaire strain, were detected in all regions and were, over-all, more abundant than antibodies against the other antigens. ebola and marburg a ... | 1983 | 6419422 |