In 2016, Dr. Goldberg, an epidemiologist and veterinarian at the University of Wisconsin, Madison, and head of the Kibale EcoHealth Project, was approached by the Pan African Sanctuary Alliance to try to solve the mystery. He and his colleagues at Wisconsin joined forces with other veterinarians and biologists in Africa and elsewhere to undertake a comprehensive analysis of blood and tissue from the dead chimps that had been frozen at a nearby hospital.