Hemorrhagic fever with renal syndrome: report of 11 observations

Dobrava virus carried by the yellow-necked field mouse Apodemus flavicollis, causing hemorrhagic fever with renal syndrome in Romania

Hemorrhagic fever with renal syndrome (HFRS) has been confirmed by serological methods during recent years in Romania. In the present study, focus-reduction neutralization tests (FRNT) confirmed Dobrava hantavirus (DOBV) as the causative agent in some HFRS cases, but could not distinguish between DOBV and Saaremaa virus (SAAV) infections in other cases. DOBV was detected by a DOBV-specific TaqMan assay in sera of nine patients out of 22 tested. Partial sequences of the M genomic segment of DOBV were obtained from sera of three patients and revealed the circulation of two DOBV lineages in Romania. Investigation of rodents trapped in Romania found three DOBV-positive Apodemus flavicollis out of 83 rodents tested. Two different DOBV lineages were also detected in A. flavicollis as determined from partial sequences of the M and S genomic segments. Sequences of DOBV in A. flavicollis were either identical or closely related to the sequences obtained from the HFRS patients. The DOBV strains circulating in Romania clustered in two monophyletic groups, together with strains from Slovenia and the north of Greece. This is the first evidence for the circulation of DOBV in wild rodents and for a DOBV etiology of HFRS in Romania.

Hantavirus infections in Greece--an update

Hantaviruses are emerging viruses spread worldwide and cause hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). Two pathogenic hantaviruses are present in Greece: Dobrava/Belgrade virus (DOBV) and Puumala virus (PUUV). The predominant one is DOBV, carried in Greece by the rodent Apodemus flavicollis. Most human infections are sporadic, but epidemic outbreaks were also described. The severity of the disease ranges from a mild or moderate form to severe and fatal cases. Several endemic foci for HFRS have been identified. Phylogenetic analysis of hantavirus sequences revealed a stable geographical distribution.

Puumala virus and two genetic variants of Tula virus are present in Austrian rodents

Puumala and Tula viruses are hantaviruses found in Europe and are associated with the rodents Clethrionomys glareolus and Microtus arvalis, respectively. Puumala virus is associated with the human disease nephropathia epidemica. In Austria, ten clinically diagnosed cases of nephropathia epidemica, presumably caused by Puumala virus infection, have been reported but not virologically confirmed [Leschinskaya et al., 1991; Aberle et al., 1996]. To identify the hantaviruses that are present in Austria, five species of rodents were trapped and screened for virus antibodies, antigen, and RNA. Hantaviruses were detected in two species, Cl. glareolus and M. arvalis, by reverse transcription-polymerase chain reaction (RT-PCR). RT-PCR products from Cl. glareolus tissues yielded a unique Puumala virus sequence distinct from Puumala virus sequences reported from other parts of Europe. RT-PCR products from M. arvalis tissues yielded two genetically distinct Tula virus sequences, one similar to sequences reported from Slovakia and the Czech Republic and another that appears to be a novel genetic variant of Tula virus. This is the first confirmed report of hantaviruses in Austria.

Propagation of Korean hemorrhagic fever virus in laboratory rats

Korean hemorrhagic fever virus (KHFV) has been adapted to the Wistar and Fisher strains of rats. Infection was detected by the appearance of specific antigen in the lung tissue of the infected rats at 14 to 64 days after inoculation and by the appearance of circulating antibodies in ther serum which reacted specifically with KHFV antigen in the lungs of infected Apodemus agrarius subsp. coreae 3 weeks after inoculation. Distribution of antigen in rat tissues as determined by immunofluorescent staining was the same as that in Apodemus mice except that antigen was present in the spleens of rats. Adaptation of KHFV to the laboratory rat provides an animal model that is free of wild rodent viruses and is readily available for use in studies on the characterization of KHFV.