FATAL DISSEMINATED CERCOPITHECINE HERPESVIRUS-1 (HERPES-B) INFECTION IN CYNOMOLGUS MONKEYS (MACACA-FASCICULARIS)

Two adult female cynomolgus monkeys (Macaca fascicularis) that had bee n housed together for 4 months died within 2 weeks of each other after brief illnesses. Monkey No. 1 presented with collapse, watery stool, and hypothermia and died overnight. Monkey No. 2 presented with dyspne a, nasal discharge, leukopenia, and hypoproteinemia and was euthanized after 2 days. Both animals had peritoneal effusions, massive necrosis of pharyngeal, esophageal, and gastric mucosa, and multifocal hepatic and pancreatic necrosis. Monkey No. 2 also had lingual ulcers and loc ally extensive necrosis of spleen, adrenal glands, and lymph nodes. La rge numbers of eosinophilic intranuclear inclusion bodies were present in epithelial and syncytial cells adjoining the necrotic foci in Monk ey No. 2 but were absent in Monkey No. 1. Monkey No. 1 seroconverted t o cercopithecine herpesvirus 1 (CHV-1, commonly known as herpes B) in the month before death. CHV-1 was isolated from a sample of stomach fr om Monkey No. 2, and electron microscopy of liver from this animal dem onstrated herpesvirus particles within hepatocytes. Both animals were seropositive for simian type D retrovirus, and the virus was cultured from the liver of Monkey No. 2. A diagnosis of disseminated CHV-1 infe ction was made, possibly occurring secondary to immunosuppression due to infection with simian type D retrovirus. Although a high percentage of cynomolgus monkeys are inapparently infected with CHV-1, dissemina ted disease is rare. Because infection with CHV-1 in humans is associa ted with a high fatality rate, familiarity with the lesions of dissemi nated infection with this virus is important.