TitleAbstractYear(sorted ascending)
seroepidemiology of selected arboviruses in febrile patients visiting selected health facilities in the lake/river basin areas of lake baringo, lake naivasha, and tana river, kenya.arboviruses cause emerging and re-emerging infections affecting humans and animals. they are spread primarily by blood-sucking insects such as mosquitoes, ticks, midges, and sandflies. changes in climate, ecology, demographic, land-use patterns, and increasing global travel have been linked to an upsurge in arboviral disease. outbreaks occur periodically followed by persistent low-level circulation.025700043
undiagnosed acute viral febrile illnesses, sierra leone.sierra leone in west africa is in a lassa fever-hyperendemic region that also includes guinea and liberia. each year, suspected lassa fever cases result in submission of ≈500-700 samples to the kenema government hospital lassa diagnostic laboratory in eastern sierra leone. generally only 30%-40% of samples tested are positive for lassa virus (lasv) antigen and/or lasv-specific igm; thus, 60%-70% of these patients have acute diseases of unknown origin. to investigate what other arthropod-borne an ...024959946
a genome-wide rnai screen reveals that mrna decapping restricts bunyaviral replication by limiting the pools of dcp2-accessible targets for cap-snatching.bunyaviruses are an emerging group of medically important viruses, many of which are transmitted from insects to mammals. to identify host factors that impact infection, we performed a genome-wide rnai screen in drosophila and identified 131 genes that impacted infection of the mosquito-transmitted bunyavirus rift valley fever virus (rvfv). dcp2, the catalytic component of the mrna decapping machinery, and two decapping activators, ddx6 and lsm7, were antiviral against disparate bunyaviruses in ...023824541
stem-loop recognition by ddx17 facilitates mirna processing and antiviral defense.dead-box helicases play essential roles in rna metabolism across species, but emerging data suggest that they have additional functions in immunity. through rnai screening, we identify an evolutionarily conserved and interferon-independent role for the dead-box helicase ddx17 in restricting rift valley fever virus (rvfv), a mosquito-transmitted virus in the bunyavirus family that causes severe morbidity and mortality in humans and livestock. loss of drosophila ddx17 (rm62) in cells and flies enh ...025126784
emerging infections of cns: avian influenza a virus, rift valley fever virus and human parechovirus.history is replete with emergent pandemic infections that have decimated the human population. given the shear mass of humans that now crowd the earth, there is every reason to suspect history will repeat itself. we describe three rna viruses that have recently emerged in the human population to mediate severe neurological disease. these new diseases are results of new mutations in the infectious agents or new exposure pathways to the agents or both. to appreciate their pathogenesis, we summariz ...026276027
blood meal analysis and virus detection in blood-fed mosquitoes collected during the 2006-2007 rift valley fever outbreak in kenya.rift valley fever (rvf) is a zoonosis of domestic ruminants in africa. blood-fed mosquitoes collected during the 2006-2007 rvf outbreak in kenya were analyzed to determine the virus infection status and animal source of the blood meals.025229704
reemergence of rift valley fever, mauritania, 2010.a rift valley fever (rvf) outbreak in humans and animals occurred in mauritania in 2010. thirty cases of rvf in humans and 3 deaths were identified. rvfv isolates were recovered from humans, camels, sheep, goats, and culex antennatus mosquitoes. phylogenetic analysis of isolates indicated a virus origin from western africa.024447381
rift valley fever outbreak, southern mauritania, 2012.after a period of heavy rainfall, an outbreak of rift valley fever occurred in southern mauritania during september-november 2012. a total of 41 human cases were confirmed, including 13 deaths, and 12 rift valley fever virus strains were isolated. moudjeria and temchecket departments were the most affected areas.024447334
unexpected rift valley fever outbreak, northern mauritania.during september-october 2010, an unprecedented outbreak of rift valley fever was reported in the northern sahelian region of mauritania after exceptionally heavy rainfall. camels probably played a central role in the local amplification of the virus. we describe the main clinical signs (hemorrhagic fever, icterus, and nervous symptoms) observed during the outbreak.022000364
genome analysis of rift valley fever virus, further confirmation of a first human case of rift valley fever in 2007 in comoros, we isolated rift valley fever virus in suspected human cases. these viruses are genetically closely linked to the 2006-2007 isolates from kenya.022608405
countermeasure development for rift valley fever: deletion, modification or targeting of major virulence factor nss.rift valley fever (rvf) is a mosquito-borne zoonotic disease characterized by a high rate of abortion in ruminants, and febrile illness, hemorrhagic fever, retinitis and encephalitis in humans. rvf is caused by the rvf virus (rvfv), belonging to the genus phlebovirus of the family bunyaviridae. rvfv encodes a major virulence factor, nss, which is dispensable for viral replication, yet required for evasion of host innate immune responses. rvfv nss inhibits host gene upregulation at the transcript ...024910709
seroprevalence of antibodies against chikungunya, dengue, and rift valley fever viruses after febrile illness outbreak, october 2009, two-3 months after an outbreak of a febrile disease with joint pain on the eastern coast of madagascar, we assessed serologic markers for chikungunya virus (chikv), dengue virus (denv), and rift valley fever virus (rvfv) in 1,244 pregnant women at 6 locations. in 2 eastern coast towns, igg seroprevalence against chikv was 45% and 23%; igm seroprevalence was 28% and 5%. igg seroprevalence against denv was 17% and 11%. no anti-denv igm was detected. at 4 locations, 450-1,300 m hig ...023092548
ngari virus in goats during rift valley fever outbreak, mauritania, 2010. 025419696
rift valley fever : a report of three cases of laboratory infection and the experimental transmission of the disease to ferrets.three cases of rift valley fever in human individuals are reported. the virus was recovered from the respiratory tract of the patients and was transmitted to ferrets by the intranasal route. the experimental disease so produced in ferrets is characterized by fever, marked pulmonary lesions, and hemorrhagic phenomena. the results indicate that the virus of rift valley fever belongs to the group of filterable viruses which may gain entrance to the human body through the respiratory tract. the diff ...193519870425
human infection with rift valley fever virus and immunity twelve years after single attack. 194720239431
[not available]. 194818916321
rift valley fever; isolation of the virus from wild mosquitoes. 194818868961
rift valley fever; transmission of the virus by mosquitoes. 194918128095
rift valley fever; the neurotropic adaptation of the virus and the experimental use of this modified virus as a vaccine. 194918128091
[pantotropic virus. iv. rift valley fever virus]. 195014781478
the development of neurotropism in rift valley fever virus. 195024537996
notes on rift valley fever. 195113249478
epidemiological notes on some viruses isolated in uganda; yellow fever, rift valley fever, bwamba fever, west nile, mengo, semliki forest, bunyamwera, ntaya, uganda s and zika viruses. 195313077697
different-sized infective particles of rift valley fever virus. 195413165719
destruction of tumour cells by rift valley fever virus. 195413213987
[inhibition of multiplication of rift valley fever virus by homologous virus irradiated by ultraviolet rays]. 195513317292
a brain factor influencing the viability of neurotropic rift valley fever. 195513265798
propagation of rift valley fever virus in ascites hepatoma cells of the rat: production of a new variant of the virus. 195513267977
plaque formation with rift valley fever virus. 195513267991
multiplication of neurotropic rift valley fever virus in ehrlich ascites tumor cells. 195513405632
rift valley fever virus in mice. i. general features of the infection. 195613315885
rift valley fever virus in mice. ii. adsorption and multiplication of virus. 195613315886
rift valley fever virus in mice. iii. further quantitative features of the infective process. 195613315887
rift valley fever virus in mice. iv. incomplete virus; its production and properties. 195613315888
the coagulation defect in rift valley fever and yellow fever virus infections. 195613340674
rift valley fever virus in mice. v. the properties of a haemagglutinin present in infective serum. 195613374199
[inhibition of multiplication of virus in rift valley fever by homologous virus irradiated with ultraviolet rays. ii]. 195613365226
interference between active and ultraviolet-irradiated rift valley fever virus. 195713416526
a variant of rift valley fever virus. 195713495627
studies on arthropod-borne viruses of tongaland. v. isolation of bunyamwera and rift valley fever viruses from mosquitoes. 195713506705
rift valley fever virus in mice. vi. histological changes in the liver in relation to virus multiplication. 195713522505
rift valley fever in southern rhodesia. 195813573432
[further notes on the interference of the inactive virus of rift valley fever with the active homologous virus]. 195813597385
[multiplication of the neurotropic strain of rift valley fever virus in the spleen and liver of mice]. 195813639453
multiplication of rift valley fever virus in human liver cell culture with special reference to production complement fixing antigen. 195914406176
rift valley fever virus in the one-day-old chick embryo. 195913631254
pharmacologically active peptides in the blood and urine of animals infected with babesia rodhaini and other pathogenic organisms.the blood and urine of mice and rats infected with babesia rodhaini contain substances which stimulate the isolated guinea-pig ileum and rat duodenum. the amount of active material excreted increases as the infection increases. the active substances are stable to boiling with hydrochloric acid but not with alkali; they pass through a cellophane membrane and are soluble in hot ethanol. they are destroyed rapidly by papain and less rapidly by chymotrypsin, but are unaffected by trypsin or pepsin. ...196013851100
[conditions necessary for interference of the neutropic virus with the pantropic virus of rift valley fever]. 196013853858
neutralizing antibody response of sheep to pantropic and neutrotropic rift valley fever virus. 196213876399
the development of a formalin-killed rift valley fever virus vaccine for use in man. 196213990748
purification and electron microscopy of pantropic rift valley fever virus. 196314043418
the effect of recently isolated strains of rift valley fever virus on lamb testis cell cultures. 196314068962
a slowly sedimenting infectious component of rift valley fever virus. 196314099024
rift valley fever virus hepatitis: light and electron microscopic studies in the mouse. 196319971024
immunization against rift valley fever. the development of vaccines from nonprimate cell cultures and chick embryos. 196313968362
physical and serological investigation of rift valley fever antigens. 196414171274
[animal hepato-neurotropic viral infections and human viral hepatitis. comparative pathological note]. 196414147320
immunization against rift valley fever virus. studies on the immunogenicity of lyophilized formalin-inactivated vaccine. 196414202259
alteration in virulence of rift valley fever virus during serial passage in lamb testis cells. 196514263453
titration of rift valley fever virus in hamster kidney cells in the absence of serum. 196514266928
protection of mice and lambs against pantropic rift valley fever virus, using immune serum. 196514269221
stability of rift valley fever virus at 4 c. 19676029841
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 ...19676035052
experimental infection of cattle with pantropic rift valley fever virus. 19676064502
biological characteristics of plaque variants of rift valley fever virus. 19676070948
electron microscopic studies on bhk 21 cells infected with rift valley fever virus. 19685729635
growth of rift valley fever virus in human diploid (wi-38) cells. 19695766737
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 ...19695780399
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 ...19695814993
immunofluorescent cell-counting assay of rift valley fever virus. 19694893388
detection of rift valley fever virus by the fluorescent antibody technique in organs of experimentally infected animals. 19704926635
the clinical aspects of rift valley fever virus in household pets. i. susceptibility of the dog. 19705410787
relationship between plaque assay and the mouse assay for titrating rift valley fever virus. 19705457747
the clinical aspects of rift valley fever virus in household pets. ii. susceptibility of the cat. 19705460684
the clinical aspects of rift valley fever virus in household pets. 3. pathologic changes in the dog and cat. 19705460685
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 ...19705494763
heat- and acid-labile virus-inhibiting factor or interferon induced by rift valley fever virus in mice. 19715003260
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.19715103483
growth of pathogenic virus in a large-scale tissue culture system.a model system is described for the mass propagation of rift valley fever (rvf) virus, utilizing large-volume fermentor units for suspension culture of tissue cells and the subsequent production of virus. comparisons between laboratory- and fermentor-scale operations of tissue cell growth gave equivalent results. cell viability dropped 24 to 30 hr postinfection with a subsequent virus yield between 10(8.0) and 10(9.0) mouse intracerebral median lethal doses per milliliter. infecting volumes of t ...19715544288
susceptibility of dogs and cats to rift valley fever by inhalation or ingestion of virus. 19725016294
the pathogenicity of rift valley fever virus for the baboon. 19724558832
induction of virus-inhibiting factor or interferon in mice by strains with different virulence of rift valley fever virus. 19724632205
long term existence of rift valley fever virus in immune mice. 19734805358
fluorescent and neutralizing antibody response to infection by rift valley fever virus. 19734588885
rift valley fever. 2. attempts to transmit virus with seven species of mosquito. 19734148061
rift valley fever. 3. viraemia in cattle and sheep. 4. the susceptibility of mice and hamsters in relation to transmission of virus by mosquitoes. 19734149110
selection of avirulent variants of rift valley fever virus. 19744465474
observations on the epidemiology of rift valley fever in kenya.the epizootic range of rift valley fever in kenya is defined from the results of virus isolations during epizootics, and form an extensive serological survey of cattle which were exposed during an epizootic. a study of the sera from a wide range of wild bovidae sampled immediately after the epizootic, showed that they did not act as reservoir or amplifying hosts for rvf. virus isolation attempts from a variety of rodents proved negative. rift valley fever did not persist between epizootics by pr ...19751058243
experimental rift valley fever in west african dwarf sheep.west african dwarf sheep were challenged with a low mouse brain-passaged rift valley fever virus (ib-ar 55172) isolated from nigeria. viraemia, mild febrile reaction and neutralising antibodies were demonstrated in inoculated animals.19751144929
demonstration of nuclear immunofluorescence in rift valley fever infected cells.eosinophilic intranuclear filaments described previously in rift valley fever infected cells, were shown to fluoresce specifically in an indirect technique with antiserum to the virus. actinomycin d failed to suppress development of the filaments or replication of the virus.1977323417
hydrops amnii in sheep associated with hydranencephaly and arthrogryposis with wesselsbron disease and rift valley fever viruses as aetiological agents.during the 1974/75 lambing season numerous reports were received from various parts of the republic of south africa and south west africa of severe abdominal distension in ewes after vaccination with the attenuated rift valley fever and/or attenuated wesselsbron disease vaccine. the ewes were vaccinated at different stages of gestation in spite of recommendations to the contrary, the syndrome being especially obvious in ewes immunized with one or both of these vaccines during the first trimester ...1977351506
rift valley fever affecting humans in south africa: a clinicopathological study. 1977561445
a preliminary report on an epidemic of rift valley fever (rvf) in egypt. 1977569679
an inactivated rift valley fever vaccine.the immunising potency of an inactivated rift valley fever (rvf) vaccine prepared from rvf virus infected mouse brain and rvf infected cell culture was studied in cattle and sheep. different doses and adjuvants were compared. in laboratory trials both cattle and sheep developed neutralising antibodies against virulent rvf virus and in cattle antibodies were still detectable 9 months after immunisation. although the immunity produced was inadequate to prevent viraemia after challenge, evidence of ...1977874947
the rift valley fever virus, agent of dengue-like epidemics: its geographical distribution and public health problems. 1978572395
virus isolation and identification from cases of rift valley fever virus infection in egypt. 1978572404
epidemic of rift valley fever (rvf) in egypt: virological diagnosis of rvf in man. 1978572405
rift valley fever virus infections in egypt: pathological and virological findings in man.ten strains of rift valley fever virus were isolated from serum samples from acute human cases collected during an epidemic of undifferentiated febrile illness. post-mortem samples were obtained from two fatal infections. severe liver necrosis, interstitial pneumonia and myocardial degeneration were seen. rift valley fever virus was isolated from post-mortem samples of liver, cerebro-spinal, pericardial and pleural fluid and from a throat swab. the virus was also isolated from nasopharyngeal was ...1978568328
studies on rift valley fever in some african murids (rodentia: muridae).brains, spleens and livers of 2214 murids, 27 shrews and 7 dormice, trapped at 7 sites in rhodesia, were tested in 277 pools for the presence of rift valley fever virus. there were no isolations of rift valley fever, but 69 isolations of an unidentified virus were obtained. sixteen out of 867 sera had low-titre haemagglutination-inhibition activity against rift valley fever antigen, but only one out of 1260 sera had neutralizing antibody. the evidence suggests that murids fail to encounter infec ...1978632561
rift valley fever: an historical perspective. 1978752698
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