Understanding EEHV. Ahead of the new Elephant Trek habitat opening, Dr. Jess from the Cincinnati Zoo explains the EEHV viral infection that can be fatal to elephants living in both the wild and in zoos. The Cincinnati Zoo has a new lab and technician to help test the elephants and hopefully catch the virus early. Scientists, researchers and elephant care experts are working to learn more about treatments and eventual prevention to help protect the world’s elephant populations.