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S Vene

Publications and source records attributed to S Vene.

At least 37 records · Page 2Linked to original sources

Vector-borne viral diseases in Sweden--a short review.

Ockelbo disease, caused by a Sindbis-related virus transmitted to man by mosquitoes, was first described in the central part of Sweden in the 1960s as clusters of patients with fever, arthralgia and rash. An average annual rate of 30 cases was recorded in the 1980s but no cases have been diagnosed during the last few years. Nephropathia epidemica (NE) characterized by fever, abdominal pain and renal dysfunction has been known to cause considerable morbidity in Sweden during the last 60 years but the etiologic agent (Puumala virus) was not isolated until 1983. This virus's main reservoir is the bank vole (Clethrionomys glareolus). NE is endemic in the northern two thirds of Sweden where more than a hundred cases are diagnosed each year. Tick-borne encephalitis transmitted by Ixodes ricinus ticks is restricted to the archipelago and Lake M-alaren on the east coast close to Stockholm. Between 30 and 110 cases are diagnosed every year. Inkoo virus, a California encephalitis group virus, has been isolated from mosquitoes in Sweden. The antibody prevalence to Inkoo virus is very high in a normal population, but no disease has as yet been associated with this virus in Sweden. Among the vector-borne virus diseases imported to Sweden, dengue is the most important, with approximately 50 cases recorded every year.

Alphavirus Infections↗

Viral etiology of acute childhood encephalitis in Beijing diagnosed by analysis of single samples.

OBJECTIVE: To understand the viral etiology of acute childhood encephalitis in Beijing. METHODS: Ninety-seven Chinese children (between 7 months and 13 years of age) with acute encephalitis were retrospectively investigated. They were treated in Beijing Children's Hospital between June, 1991, and October, 1994. Different serologic methods (immunofluorescence assay, enzyme-linked immunosorbent assay, solid phase reverse immunosorbent test) were used for detection of IgM antibody to enteroviruses, herpesviruses, mumps, measles, rubella and Japanese encephalitis virus. The viral DNA of six herpesviruses was detected by polymerase chain reaction. RESULTS: Viral etiology was identified in 35 of 97 (36.0%) cases. The most frequently identified pathogens were enteroviruses (15; 15.4%), followed by mumps (7; 7.2%), rubella (6; 6.1%), Japanese encephalitis virus (5; 5.1%), human herpesvirus 6 (2; 2.0%), herpes simplex virus (2; 2.0%) and Epstein-Barr virus (1; 1.0%). IgM antibody in cerebrospinal fluid was detected for enterovirus, mumps and rubella viruses. CONCLUSIONS: Enteroviruses were the most frequent viral pathogens of acute childhood encephalitis in Beijing. Detection of IgM in cerebrospinal fluid may be useful for diagnosis in certain cases of viral encephalitis.

Acute Disease↗

Nuclear colocalization of the Ro 60 kDa autoantigen and a subset of U snRNP domains.

The Ro 60 kDa protein is an RNA binding molecule present both in the cytoplasm and in the nucleus. Cytoplasmic Ro 60 kDa is complexed to other proteins and to certain RNAs denoted hYRNAs. This RNA-protein complex is also known as the Ro/SSA antigen recognized by sera from patients with certain autoimmune disorders. Components interacting with the nuclear Ro 60 kDa protein fraction in mammalian cells have not been identified. To look for an association with previously known nuclear structures, rabbit antisera to the amino- and carboxy-terminal parts of the Ro 60 kDa protein were used in immunomorphological studies on HeLa cells. A strong speckled nuclear pattern and a weak cytoplasmic staining were detected. Double immunofluorescence staining with affinity purified anti-Ro 60 kDa antibodies and monoclonal antibodies recognizing the Sm and RNP antigens of the U snRNPs, displayed colocalization. Another U snRNP containing nuclear compartment, the coiled bodies, did not contain any Ro 60 kDa protein. Cells infected with a toga virus demonstrated redistribution of both U snRNP antigens and the Ro 60 kDa protein with retained colocalization. These results indicate a role for the nuclear fraction of the Ro 60 kDa protein in RNA processing.

Animals↗

Indirect immunofluorescence for serological diagnosis of dengue virus infections in Swedish patients.

BACKGROUND: An increasing number of travellers to dengue endemic areas has emphasized the need for an easy and reliable serological test for diagnosis of dengue virus infections. OBJECTIVES: Indirect immunofluorescence (IF) and hemagglutination inhibition (HI) tests were compared for serological diagnosis of dengue fever (DF). STUDY DESIGN: Sera from patients with clinical symptoms compatible with DF and a travel history comprising dengue endemic areas were included in the study. Paired serum samples from 24 patients and single convalescent sera from five patients were investigated by HI and IF. Paired sera from ten patients were investigated by plaque reduction neutralization test (PRNT) in order to confirm the HI/IF results. RESULTS: In twelve of the patients with paired sera a sero-conversion or a significant (4-fold) antibody titer rise was seen with HI as well as with IF. Four patients with stationary HI-titers had significant titer rises when investigated by IF. Stationary or declining HI- and IF-titers were found in the remaining eight patients. The five single sera were antibody-positive by both methods. Investigation by PRNT of paired sera from ten patients confirmed the IF results. A total of 298 serum samples (paired sera or early convalescent samples) were investigated for dengue antibodies by IF. A sero-conversion, significant titer-rise or an IF-titer of 320 was generally seen 7-13 days post onset of disease. During the years 1991-1993 altogether 161 cases of dengue were diagnosed by IF in Swedish patients, a majority of which had travelled to Southeast Asia. CONCLUSION: Antibody detection by indirect IF proved to be at least as reliable as HI for diagnosis of dengue infections in Swedish patients. The specificity of the IF was ensured by testing the sera of ten patients for serotype specific neutralizing dengue antibodies.

Journal Article↗

Development of specific antibody patterns and clinical symptoms following Ockelbo virus infection.

Sixteen patients with symptoms typical for Ockelbo disease (rash, arthralgia, fever) were enrolled in a 2 1/2 year study, during which clinical symptoms were recorded and ELISA was employed to study specific IgM, IgG and IgG subclass development. Initially, all patients presented with rash and arthralgia, and five patients still suffered from joint symptoms at the end of the study period. Ockelbo virus specific IgM was detected during the first week post onset in 6 patients and in 15 patients by day 14. One patient failed to develop specific IgM and was later diagnosed with a human parvovirus B19 infection. All patients were IgM-negative 2 1/2 years post onset. Seroconversions or significant titer rises for specific total IgG were seen in 15 patients. IgG titers generally peaked within one year but in two patients maximum titers were seen 2 1/2 years post onset. Development of IgG1 followed that of total IgG, while IgG3, after an initial increase in all Ockelbo disease patients, remained at peak levels for one year in four patients, three of whom still had detectable IgG3 at the end of the study period. Ockelbo virus specific IgG2 or IgG4 was not detected in any of the patients.

Adult↗

Detection of Ockelbo virus RNA in skin biopsies by polymerase chain reaction.

A sensitive assay based on the polymerase chain reaction for the detection of Ockelbo virus RNA was developed. Two primer pairs from the gene coding for the E2 glycoprotein were chosen. By use of a nested strategy for the primers, as few as 1 to 10 PFU could be detected. The amplified products were visualized as bands of appropriate size on ethidium bromide-stained agarose gels. The primer pairs allowed amplification of several Ockelbo and Sindbis virus isolates but discriminated between these and other alphaviruses. Ockelbo virus RNA was detected in 4 of 10 skin biopsy specimens collected during the acute stage of the disease. The identities of the amplified products were confirmed by restriction endonuclease cleavage. Acute- and convalescent-phase sera as well as lymphocytes collected during the convalescent phase were negative by the polymerase chain reaction. No infectious virus could be recovered from any of the specimens.

Base Sequence↗

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 be distinct from prototype Sindbis virus, and the Acrocephalus strain from Slovakia was shown to be identical to prototype Sindbis virus. All other strains, including Ockelbo virus isolates, were shown to be subtypes of prototype Sindbis virus.

Alphavirus↗

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 of July and the first week of October, with a peak during the second half of August. During the 8 years studied (1981-8), an average of 31 Ockelbo patients/year were diagnosed. The antibody prevalence rates in the oldest age groups were 20-40 times higher than the accumulated life-risk of being diagnosed and reported as an Ockelbo disease patient, which suggests that many cases are asymptomatic and/or unreported.

Adolescent↗

Incidence of sand fly fever among Swedish United Nations soldiers on Cyprus during 1985.

Members of a Swedish United Nations (UN) battalion of 362 soldiers were bled just before and immediately after their 6 month tour of duty in Cyprus during 1985. Sera were tested for presence of specific antibodies to sand fly fever (SF) Sicilian, SF Naples, and Toscana viruses by both indirect immunofluorescence antibody test (IFT) and plaque reduction neutralization test (PRNT). Of 298 serum pairs available, seroconversion was noted in 11 soldiers: 7 cases for SF Sicilian, 3 for SF Naples, and 1 for Toscana virus. IFT and PRNT revealed identical results. Seroconversion was associated with clinical disease in 7 out of 7, 2 out of 3, and 0 out of 1 for SF Sicilian, SF Naples, and Toscana infections, respectively. Virus isolation was attempted on acute-phase sera collected from febrile patients. Of 5 such acute-phase sera from patients with serologically verified SF, virus was recovered from 2: 1 strain of SF Sicilian virus and 1 strain of SF Naples virus.

Adult↗

Countrywide epidemics of Chlamydia pneumoniae, strain TWAR, in Scandinavia, 1981-1983.

There was a large increase in incidence of reported cases of ornithosis in Norway, Sweden, and Denmark in 1981-1983. Serologic evidence indicated that the epidemic was caused by the newly described Chlamydia organism, C. pneumoniae, strain TWAR. When serum samples that had been shown to contain Chlamydia complement fixing antibodies were tested by the microimmunofluorescence method with TWAR antigen, 49%-71% showed evidence of current TWAR infection during the epidemic years compared with 10%-20% in nonepidemic years.

Adolescent↗

Serum antibody responses to individual viral polypeptides in human rotavirus infections.

A radioimmunoprecipitation assay (RIPA) was used to study the serum antibody responses to individual polypeptides that developed after infection with viruses from human rotavirus subgroups I and II. Paired sera from eight children (1 to 8.5 years of age) were used in the study. Although all of the eight acute sera were negative by the complement fixation test, four of them were positive by RIPA, indicating a previous infection by rotavirus. A significant difference in the number of polypeptides immunoprecipitated was seen among the convalescent sera. The number of polypeptides immunoprecipitated was found to be related to previous infection experience. At most, ten different polypeptides were immunoprecipitated: seven structural polypeptides VP1 to VP7 and three non-structural polypeptides, NS1, NS2 and NS3. No sera immunoprecipitated VP8 or VP9. Acute sera positive by RIPA immunoprecipitated up to five polypeptides, VP1, VP2, VP3, VP4 and VP6. One of the non-structural proteins (NS2) was found to be particularly immunogenic, since antibodies to this polypeptide were detected in several convalescent sera. Among the structural proteins VP2 and VP6 were found to be the two immunodominant polypeptides which were recognized by all convalescent sera. Only three convalescent sera immunoprecipitated VP7, the major type-specific antigen responsible for inducing neutralizing antibodies. Three of four originally seronegative children with no reactivity in the convalescent sera to VP7 developed neutralizing antibodies to a single serotype. One child developed antibodies to two serotypes.

Antibodies, Viral↗

The first human case of domestic Q fever in Sweden.

A case of Q fever in a 56-year-old man is reported. The patient had visited Mallorca six months prior to the present disease. Except for that he had not been outside Sweden for several years, thus being the first known case of Q fever acquired in this country.

Humans↗