Viruses use living beings—like you!—to survive.
Unlike bacteria, these tiny germs can’t multiply if they’re not inside an animal’s body. They survive by spreading from body to body all over the world.
A few viruses, including the cold virus, travel through air. Most killer viruses don’t. These deadly germs spread by direct contact, like when an infected mosquito bites a human. The germs enter the victim’s bloodstream, and once they’re in, they can do serious damage. One group of germs is called hemorrhagic (hem-uh-RAJ-ik) fever viruses. First, the victims gets feverish, and then they can bleed to death internally.
The map below shows the birthplaces of some hemorrhagic fever viruses and the animals that spread them. Some of these sites have only occasional outbreaks. However, every year these viruses make people sick in places all over the world.
