antibodies to ockelbo virus in three orders of birds (anseriformes, galliformes and passeriformes) in sweden.sera from 324 birds collected in an ockelbo virus disease endemic area in central sweden were examined for the presence of specific antibodies to ockelbo virus by a plaque reduction neutralization test. birds examined belonged to the orders anseriformes (n = 207), galliformes (n = 66) and passeriformes (n = 51). ockelbo virus neutralizing antibodies were detected in 26 (8%) of the specimens, including species from each of the three orders tested. specific antibodies found in caged birds and in 6 ...19921312646
effect of environmental temperature on the vector competence of culex pipiens and cx. torrentium for ockelbo virus.the effects of environmental temperature on ockelbo virus infection, dissemination, and transmission were studied in culex torrentium and in the uppsala and the el gabal strains of cx. pipiens. temperatures tested included 10 degrees c, 17 degrees c, 24 degrees c, and a cyclic (10-24 degrees c, mean = 17 degrees c) regimen designed to mimic typical hourly temperatures in an area endemic for ockelbo disease in sweden during the transmission season. the vector competence of both the uppsala and th ...19902173433
effect of environmental temperature on the vector competence of aedes aegypti and ae. taeniorhynchus for ockelbo virus.studies were conducted to determine the effect of environmental temperature on the ability of aedes aegypti and ae. taeniorhynchus to transmit ockelbo (ock) virus. temperatures tested were 10 degrees c, 17 degrees c, 24 degrees c, and a cyclic (10-24 degrees c, mean = 17 degrees c) regimen designed to mimic continuously temperatures to which a mosquito might be exposed in july and august in central sweden. both species were highly susceptible to oral infection, with no consistent association bet ...19902173434
ecologic studies of mosquitoes and birds as hosts of ockelbo virus in sweden and isolation of inkoo and batai viruses from mosquitoes.field studies were conducted in central sweden from 1983 through 1985 to obtain information on the etiologic agent of ockelbo disease, described in sweden in the 1960s and probably identical to pogosta disease in finland and to karelian fever in the western ussr. mosquitoes (63,644) collected during this 3 year period yielded 21 virus strains. ockelbo virus isolations were from culiseta morsitans (5 strains), culex pipiens and/or cx. torrentium (6 strains), and aedes cinereus (3 strains). inkoo ...19892572178
antigenic comparison of ockelbo virus isolates from sweden and russia with sindbis virus isolates from europe, africa, and australia: further evidence for variation among alphaviruses.the plaque-reduction neutralization test (prnt) was used to compare 15 isolates of ockelbo virus from sweden, one isolate of ockelbo virus from russia, the egyptian prototype sindbis virus, and sindbis-like viruses from slovakia, south africa, cameroon, and australia. strains from northern europe (sweden and russia) were indistinguishable by prnt. we observed some antigenic variation between isolates of sindbis virus from europe, africa, and australia. an australian strain (c-377) was shown to b ...19937902675
swedish culex torrentium and cx. pipiens (diptera: culicidae) as experimental vectors of ockelbo virus.the ability of the sibling species culex pipiens (l.) and culex torrentium (martini) from central sweden to transmit ockelbo (ock) virus was determined. both species became infected after ingesting ock virus from a viremic chicken; they transmitted this virus to chickens after 21-28 d of extrinsic incubation. in cx. torrentium, infection rates were 90% or higher, and all 10 refeeding mosquitoes transmitted virus after feeding on chickens with a viremia of at least 10(3.0) plaque-forming units (p ...19902167372
ockelbo virus (togaviridae: alphavirus) neutralizing antibodies in experimentally infected swedish birds.the ability of native swedish birds to produce and maintain production of ockelbo virus neutralizing (nt) antibodies were evaluated experimentally between 6 june 1990 and 27 july 1991. after experimental infection of 57 birds of the orders anseriformes and passeriformes with ockelbo virus, these birds were examined for ockelbo virus nt antibodies at 5 days, and at 1, 3, 6, 9, and 12 mo after inoculation. one month after inoculation, nt antibodies were more prevalent in birds with a detectable vi ...19968627942
geographical and temporal distribution of ockelbo disease in sweden.the incidence of ockelbo disease and the prevalence of ockelbo virus neutralizing antibodies were investigated in a sample of the swedish population. the disease occurs throughout most of sweden but with higher incidence and antibody prevalence rates in the central part of the country. it generally affects middle-aged men and women, with equal incidence between sexes, and is uncommon in people younger than 20 years of age. the disease occurs during a short period each year between the third week ...19911646735
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