[Delta virus: now also detected in Austria. A defective virus as a pathogenic agent].

delta-virus, first described by Rizzetto, is a defective virus dependent on hepatitis B virus as helper-virus. Superinfection of inactive hepatitis B with delta-virus leads to chronic active or even fulminant hepatitis. It can be detected by RIA or ELISA and its distribution is world-wide. Also in Austria, 4 sera with antibodies to delta-virus have been found among 138 HBsAg-positive sera. No therapy is known, but vaccination against HB virus also prevents the propagation of delta-virus.