[The interferon system in ducks infected with viral hepatitis B]

The duck peripheral blood lymphocytes and spleen cells were shown to be relatively resistant to interferon induction by viral (NDV) and nonviral (dsRNA) inducers as well as to Con A induction of gamma-interferon. The concentration of the inducers had to be increased 4-5-fold to induce interferon production. Charry valley ducks produced more alpha-interferon than Peking ducks. The level of interferon production induced by NDV and dsRNA (Ridostin) was similar in DHBV-positive Peking ducks and in the control group, but in the infected Charry valley ducks interferon production was lower than in the controls (224 to 180 U/0.1 ml in NDV-induced and from 192 to 43.3 U/0.1 ml in dsRNA-induced). Early bursectomy brought down the interferon production in non-infected ducts, but in DHBV-positive bursectomized ducks (Y) the level of interferon was higher than in the control bursectomized ducks.