142 Sochi virus as a highly pathogenic and life-threatening agent

A new genotype of Dobrava-Belgrade virus (DOBV), Sochi virus, was found in the Black Sea field mouse, Apodemus ponticus. This mouse is naturally occurring in the Southern European Russia and transcaucasian countries between the Black and the Caspian Sea. Recently, cell culture isolates of Sochi virus have been generated from A. ponticus and an HFRS patient with fatal outcome. At the present state of knowledge, Sochi virus seems to be the most dangerous representative of DOBV. Virus diagnostics in patients was accomplished by immunofluorescence assay, serotyping of neutralizing antibodies, and RT-PCR amplification of viral genome segments. In phylogenetic analyses we found a spatial clustering of the viral nucleotide sequences derived from patients and mice trapped at different localities of the Russian Black Sea coast region demonstrating Sochi virus as the causal pathogenic agent in humans. We currently oversee in detail the clinical courses of 51 patients with confirmed Sochi virus infection. The case fatality rate was determined to be as high as 14%. Nearly 60% of clinical courses were defined as severe (including deaths) and nearly 40% as moderate. Four times more males than females were affected. Quite unusual for hantavirus disease, also young people became ill due to Sochi virus infection; 10% of patients were found between 7 and 15 years old and the age average of all patients was not much higher than 30 years. There is an urgent need to monitor the epidemiology of the new virus—not only because of its health-threatening character in this particular geographical area but also because of its potential ability to overcome host species barriers. Colonization of nearly related host species, as A. flavicollis or A. sylvaticus, by the virus could dramatically increase its geographical spread and consequently further enhance the danger for the human population.