Scientists identified
Marburg virus in 1967, when small outbreaks occurred among lab workers in Germany who were exposed to infected monkeys imported from Uganda. Marburg virus is similar to Ebola in that both can cause hemorrhagic fever, meaning that infected people develop high fevers and bleeding throughout the body that can lead to shock, organ failure and death. The mortality rate in the first outbreak was 25%, but it was more than 80% in the 1998-2000 outbreak in the Democratic Republic of Congo, as well as in the 2005 outbreak in Angola,.
The first known Ebola outbreaks in humans struck simultaneously in the Republic of the Sudan and the Democratic Republic of Congo in 1976. Ebola is spread through contact with blood or other body fluids, or tissue from infected people or animals. The known strains vary dramatically in their deadliness. One strain, Ebola Reston, doesn't even make people sick. But for the Bundibugyo strain, the fatality rate is up to 50%, and it is up to 71% for the Sudan strain.
Although rabies vaccines for pets, which were introduced in the 1920s, have helped make the disease exceedingly rare in the developed world, this condition remains a serious problem in India and parts of Africa. It destroys the brain, it's a really, really bad disease. We have a vaccine against rabies, and we have antibodies that work against rabies, so if someone gets
bitten by a rabid animal we can treat this person. If you don't get treatment, there's a 100% possibility you will die."
In the modern world, the deadliest virus of all may be HIV. It is still the one that is the biggest killers. An estimated 32 million people have died from HIV since the disease was first recognized in the early 1980s. The infectious disease that takes the biggest toll on mankind right now is HIV.