“In 1986 – the year before Peter Cardinal died – Gene Johnson had done an experiment that showed that Marburg and Ebola can indeed travel through the air. He infected monkeys with Marburg and Ebola by letting them breathe it into their lungs, and he discovered that a very small dose of airborne Marburg or Ebola could start an explosive infection in a monkey. Therefore, Johnson wanted the members of the expedition to wear breathing apparatus inside the cave.”

“In 1986 – the year before Peter Cardinal died – Gene Johnson had done an experiment that showed that Marburg and Ebola can indeed travel through the air. He infected monkeys with Marburg and Ebola by letting them breathe it into their lungs, and he discovered that a very small dose of airborne Marburg or Ebola could start an explosive infection in a monkey. Therefore, Johnson wanted the members of the expedition to wear breathing apparatus inside the cave.”

— Richard Preston