HUMAN INFECTIONS WITH BORNA DISEASE VIRUS - SEROPREVALENCE IN PATIENTS WITH CHRONIC DISEASES AND HEALTHY-INDIVIDUALS

Borna disease virus (BDV) is as yet an unclassified infectious agent w hich causes a neurologic disease in horses and sheep and is transmissi ble to other animal species. Human sera were tested for BDV-specific a ntibodies by immunofluorescence and immunoprecipitation. The sera were collected from three thousand subjects in Europe, the USA, and Africa classified by clinical syndromes/infectious diseases, and from health y controls. In all three continents, positive serum samples were detec ted which recognized the major BDV antigen of 38/40 KD present in the nuclei of infected cells. In contrast to 2% of seropositives among the normal population, significantly higher prevalences (13-14%) were pre sent among patients with chronic progressive diseases of the brain and the immune system. In children, antibody frequencies were two to four times higher than in adults. The results suggest a latent infection w ith BDV in humans leading to low antigen expression in healthy subject s and frequent reactivation events in chronically ill patients.