Subacute nonsuppurative hepatitis associated with hepatitis B virus infection in two cynomolgus monkeys.

Subacute, nonsuppurative hepatitis was diagnosed in a cynomolgus monkey (Macaca fascicularis) based on histopathologic examination of a liver biopsy specimen. Clinical signs of illness included anorexia, lethargy and hepatomegaly. Abnormal laboratory findings included elevations of serum liver enzymes, bilirubin and a monocytosis. Circulating antibody (anti-HBs) against Hepatitis B surface antigen (HBsAg) was present in serum and antigens reactive with anti-HBsAg antiserum were found in the liver using an immunoperoxidase technique. Of the remaining 18 healthy monkeys in the same room, another cynomolgus monkey was HBsAg seropositive. Both of the seropositive monkeys involved arrived on the same shipment from Indonesia and had been quarantined and housed together continuously during the preceding two years.