Orbiviruses of the Kemerovo complex and neurological diseases

The viruses of the Kemerovo complex, genusOrbivirus, family Reoviridae, are widely distributed in the habitats ofIxodes ticks in Eurasia. Their incidence in ticks sometimes surpasses that of the tick-borne encephalitis virus (TEV).Neutralizing antibodies in serum of healthy residents in natural foci indicate contact with Kemerovo complex viruses in 8.5–18.0%. Kemerovo complex viruses were isolated from the cerebrospinal fluid of patients with meningitis and tick-borne encephalitis.Serological studies in neurological patients from Central Europe were carried out with the Lipovník virus (LV) serotype. Of patients from Ostrava district with confirmed tick-borne encephalitis 51% revealed concurrent neutralizing antibody response to LV. Of 36 patients from Graz district who had neutralizing antibodies to TEV in the cerebrospinal fluid (CSF), 72.5% also had CSF-LV antibodies. This finding supports the importance of concurrent LV-infection in the development of overt TE. Patients from Bratislava Region with abacterial meningitis, polyradiculoneuritis, and multiple sclerosis (MS) had LV-serum antibodies in 50%, 41.2%, and 45.2% of cases, respectively. This is a significantly higher incidence than in the control groups (P=0.05). Of MS patients 53% had LV-antibodies also in the CSF, often in combination with measles and herpes simplex type 1 virus antibodies. The relationship of LV to the etiology and course of chronic neurological diseases remains to be elucidated.