The remainder of his review focuses on ecologic factors, especially those exemplified by arbovirus diseases. He seeks to identify lessons learned from Venezuelan equine encephalitis epidemics, the equine morbillivirus outbreak in Australia, from Ebola hemorrhagic fever, rabies epidemics, from the hantavirus pulmonary syndrome epidemic and from bovine spongiform encephalopathy in cattle and new-variant Creutzfeldt-Jakob disease in humans.