Simian varicella virus (delta herpesvirus) infection of patas monkeys leading to pneumonia and encephalitis

Patas monkeys were infected with Delta herpesvirus (DHV) to determine the pathogenicity of this virus in the lung and brain in order to assess the suitability of this model for severe complications in human VZV infection. Clinically, pneumonia and encephalitis occurred following intracerebral inoculation. Intratracheal or intravascular inoculation of DHV produced pneumonia but not encephalitis. Prominent microscopic lesions included diffuse interstitial pneumonia and focal hemorrhagic encephalitis. Typical herpesvirus intranuclear inclusion bodies were noted in lung parenchymal cells and in glial cells of the brain. DHV was isolated from peripheral blood leukocytes, spleen, lymph nodes, lung, and from various sites in the peripheral and central nervous system. Fluorescent antibody staining confirmed the identity of DHV recovered from monkey tissue. This study provides further evidence that the patas-DHV model has potential for predicting drug and/or immunotherapy regimens which may be useful in treating pulmonary and neurological complications of VZV infection.