Ebola virus infection in imported primates--United States.

In late November 1989, Ebola virus was isolated from cynomolgus monkeys (Macaca fascicularis) imported into the United States from the Philippines via Amsterdam and New York. During quarantine in a primate facility in Virginia, numerous macaques died, some with findings consistent with simian hemorrhagic fever (SHF). The US Army Medical Research Institute of Infectious Diseases tested 10 animals and, from 3, isolated SHF from tissues and serum; however, 5 other animals of the 10 tested were positive for Ebola virus. Monkeys from a later shipment quarantined in a second room also had unusually high mortality and were tested by a rapid antigen detection enzyme-linked immunosorbent assay. Ebola viral antigen was detected in serum and/or tissues from 7 of these monkeys. Primary liver material from animals in both rooms exhibited particles with typical filovirus morphology by electron microscopy and Ebola virus antigen by immunohistochemistry.