[A study of duck hepatitis B virus infection in Chinese ducklings].

Intraperitoneal inoculation of duck hepatitis B virus in three different dosages (9 x 10(7), 1.8 x 10(8), 9 x 10(8) DHBV particles) into 3 to 21 day-old Chinese ducklings provided from a DHBV free flock produced a persistent infection up to 93.3% in 60 animals. The serum and liver specimens of these ducklings were examined by DNA dot blot hybridization on the 30th day after inoculation. The results showed that: (1) examination of viral DNA in liver was more sensitive and reliable than estimation of the DNA in serum for detecting DHBV infection in inoculated ducklings; (2) the liver DHBV DNA level did not coincide with the degree of liver hepatitis induced; (3) 21-day-old Chinese ducklings were also susceptible to DHBV infection, the infection rate of this group was 100% (10/10).