Canine Distemper Killed African Lions -- Drive Under Way To Prevent Further Outbreak

NEW YORK - Scientists have identified a virus that killed an estimated 1,000 lions in Africa in 1994, and they've started a campaign to prevent another outbreak.

The animals died in Tanzania's Serengeti National Park and surrounding areas, including Kenya's Masai Mara National Reserve, dropping the area's lion population to 2,000.

"This is the most dramatic die-off of lions I think anyone has ever seen," said Craig Packer, a researcher at the University of Minnesota.

The disease was first noticed in early 1994 by tourists who were taking a balloon trip in the Serengeti National Park. They noticed a lion having convulsions, and their guides contacted Melody Roelke-Parker, a wildlife veterinarian living in the park.

Analysis of tissue from dead animals showed the germ was canine distemper virus, Packer and colleagues from several countries reported in today's issue of the journal Nature. The virus strain closely matched that from a dog in a local village, suggesting that dogs were the source of the outbreak.

The lions probably didn't come into direct contact with the dogs, researchers said. Instead, the virus may have been carried into the lion populations by spotted hyenas, which scavenge in village dumps, Packer said. Jackals or leopards may have also carried in the virus, he said.

The virus gave some lions seizures, with uncontrolled thrashing and flailing of limbs before death. About 60 percent of infected lions survived, Packer said, and they "are in fine shape and they started breeding, so the population is coming back rapidly."

It would be impractical to vaccinate wild lions against the virus, he said. Instead, researchers have started a campaign to raise money to vaccinate the 30,000 domestic dogs living within 10 miles of the park.

Vaccinations began in December, but the program will have to go on indefinitely to provide continuing protection, Packer said.

Material from Washington Post is included in this report.