Woolly monkey hepatitis B virus (WMHBV) was first isolated from a 10-year-old female woolly monkey (Lagothrix lagotricha).1 This monkey was ill for 60 days prior to euthanasia. Clinical signs included partial anorexia, hunched posture, pollakiuria, weight loss, depression, ascites, and dehydration. Clinical pathology results from blood samples collected during the monkey’s illness showed elevations in LDH, GGT, ALT, AST, and bile acids, hypoalbuminemia, low serum iron, normocytic, hypochromic anemia, leukocytosis, and neutrophilia. Liver biopsy revealed multifocal areas of hepatocellular necrosis accompanied by hemorrhage, with a moderate infiltrate of neutrophils, lymphocytes, and plasma cells. Serology on current and banked serum samples showed presence of hepatitis B surface antigen (HbsAg) and core antibody (HbcAb), absence of hepatitis B surface antibody (HbsAb), and presence of WMHBV in the blood by polymerase chain reaction (PCR) for over 3 years. Gross necropsy findings included an abnormal liver with round borders, multifocal pale marbling, and a rough, dull surface, ascites, and pleural effusion. Histopathologic findings included massive, multilobular hepatic necrosis consistent with viral hepatitis. Serum PCR testing of remaining woolly monkeys held at Louisville indicated they were either chronically infected, had cleared a previous infection, or were not infected with WMHBV. Historic serum chemistries from these monkeys showed no patterns of elevation in ALT, AST, LDH, SAP, or total bilirubin and no pattern of hypoalbuminemia. Necropsies of three monkeys that died since the index case did not show evidence of viral hepatitis. Staff testing via HBsAb, HBcAB, and HbcAg showed no serologic indication of exposure to WMHBV.
A total of 80 serum samples representing 43 monkeys from 11 locations in the USA were tested for infection with WMHBV by PCR, HbsAg, HbsAb, and/or HbcAb. Of the 43 monkeys tested, 23 monkeys (53%) tested positive for infection with WMHBV. The earliest positive serum sample was collected November 3, 1987 from a monkey at Louisville Zoo that was one of several woolly monkeys imported from Dumbartonshire, Scotland in July of 1985. All 23 woolly monkeys testing positive had either been held at the Louisville Zoo or were held at another zoo holding monkeys that were once held at the Louisville Zoo.
1. Lanford, R.E., D. Chavez, K.M. Brasky, R.B. Burns, and R. Rico-Hesse. 1998. Isolation of a hepadnavirus from the woolly monkey, a New World primate. Proc. Natl. Acad. Sci. USA, Microbiol. 95: 5757–5761.