Researchers at Johns Hopkins in Baltimore and the National Zoo in Washington, D.C., have discovered the cause of death of nearly a dozen young North American zoo elephants -- fatal hemorrhaging from a previously unknown form of herpesvirus that apparently jumped from African elephants to the Asian species.

"This is very troubling because these are endangered species," said Gary Hayward, Ph.D., a Johns Hopkins scientist and co-author of a report published in the Feb. 19 Science. "And also because there may still be carrier African elephants in zoos."

Quick detection and treatment with antiviral drugs is life-saving, he added.

Asian elephants are bred more frequently in captivity than their African cousins, and a sufficient number of young elephants is necessary for bolstering the population, which is dwindling in the wild.

Of 34 Asian elephants born in zoos in the United States and Canada from 1983 to 1996, seven have died from the virus, and two more with incomplete records are suspected to have died from it. The virus appears to be latent in most African elephants, although two of seven African elephants born in North America over the past 15 years have also died from herpesvirus infection. Most of the infected elephants were young.

In their report, the scientists say that the elephant herpesvirus kills by infecting cells that line blood vessels in the heart, liver and other organs. Untreated, the virus soon causes internal bleeding and heart failure. The virus hits suddenly, killing in a few days.

The "index case," or first animal identified as having the virus, was a 16-month-old Asian elephant, Kumari -- the first elephant ever born at the National Zoo. When Kumari died in 1995, her keepers were baffled.

Soon after, Laura Richman, D.V.M., now at The Johns Hopkins School of Medicine, and Richard Montali, D.V.M., of the National Zoo, began investigating the case. When exam
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Contact: Brian Vastag
bvastag@jhmi.edu
410-955-8665
Johns Hopkins Medical Institutions
19-Feb-1999