Genetic characterization of a new hantavirus detected in Microtus arvalis from Slovakia

A new hantavirus, called Malacky, has been identified in lung tissue specimens of a vole, Microtus arvalis, by the reverse transcriptase polymerase chain reaction (RT-PCR). The voles were trapped in a geographical area in Slovakia where hemorrhagic fever with renal syndrome (HFRS) is endemic in the human population. Sequence analysis of a major part of the S segment showed this virus to represent a new subtype within Tula, a new hantavirus genetic group defined very recently.

Temporal dynamics of Puumala virus antibody prevalence in voles and of nephropathia epidemica incidence in humans

Puumala (PUU) virus is the etiologic agent of nephropathia epidemica (NE) in humans. This disease is highly endemic in Vasterbotten county, Sweden, with an annual incidence of 19.2 (range 3.7-37.4) per 100,000 inhabitants. Voles are considered to be both the main reservoir and the vector of PUU virus. A total of 3,591 rodents (mainly Clethrionomys glareolus, C. rufocanus, and Microtus agrestis) trapped in Vasterbotten between 1979 and 1987 were tested for the presence of PUU virus antibodies by enzyme-linked immunosorbent assay. The predominant species, C. glareolus (71% [2,544 of 3,591]), also had the highest antibody prevalence (19% [483 of 2,544]). In C. glareolus, the antibody prevalence rate increased with weight (age), reaching more than 50% in the heaviest weight group, and suggesting that horizontal infection may be important. The highest frequency (25%) of antibody-positive C. rufocanus was also found in the highest weight groups. Microtus agrestis showed low absolute numbers and a low antibody prevalence rate (5%). In C. glareolus, both antibody prevalence and weight were recurrently higher in the spring than in the previous fall. The antibody prevalence rate in spring was positively correlated with the vole density in the previous fall and spring. The fall antibody prevalence rate was directly dependent on C. glareolus density. The incidence of human NE in the fall was dependent on the concurrent density of C. glareolus, whereas the incidence of NE in the spring was dependent on vole density the previous fall.

Sensitive detection of hantaviruses by biotin-streptavidin enhanced immunoassays based on bank vole monoclonal antibodies

Antigen capture enzyme-linked immunosorbent assays (ELISAs) based on detection of the viral nucleocapsid protein (N) were designed for rapid diagnosis of hantavirus infections. Several combinations of bank vole (Clethrionomys glareolus) monoclonal antibodies with various N-epitope specificities were used for the development of two double-antibody sandwich forms of ELISA; PUU virus AG-ELISA for an exclusive detection of Puumala-related viruses, and Hantavirus AG-ELISA for a more extensive detection of all serotypes of hemorrhagic fever with renal syndrome (HFRS) viruses. The biotin-streptavidin system, in combination with horseradish peroxidase, rendered the assays' sensitivities similar to or even higher than immunoblotting. Calculated detection limits for the PUU virus and the Hantavirus AG-ELISAs were 405 and 50 focus forming units or 80 and 10 infected Vero E6 cells, respectively. The assays were evaluated and found to be suitable for convenient and routine detection of hantaviruses in cell cultures and in infected animal tissue.

Tula virus: a newly detected hantavirus carried by European common voles

A novel hantavirus has been discovered in European common voles, Microtus arvalis and Microtus rossiaemeridionalis. According to sequencing data for the genomic RNA S segment and nucleocapsid protein and data obtained by immunoblotting with a panel of monoclonal antibodies, the virus, designated Tula virus, is a distinct novel member of the genus Hantavirus. Phylogenetic analyses of Tula virus indicate that it is most closely related to Prospect Hill, Puumala, and Muerto Canyon viruses. The results support the view that the evolution of hantaviruses follows that of their primary carriers. Comparison of strains circulating within a local rodent population revealed a genetic drift via accumulation of base substitutions and deletions or insertions. The Tula virus population from individual animals is represented by quasispecies, indicating the potential for rapid evolution of the agent.