How Viral Diseases Spread and How to Slow Them

0:00How do viral diseases spread, and how can we slow them?

0:05A virus is a tiny particle that can only copy itself inside the cells of a host, the living thing it infects.

0:13Passing to a new host is called transmission. Here are three common routes, or paths, it can take.

0:21Route one: droplets and aerosols, tiny drops of fluid that an infected person breathes out.

0:28Larger droplets soon fall to the ground. Smaller aerosols can float in the air for longer.

0:36Influenza, or flu, spreads this way, including the H1N1 flu that spread around the world in 2009.

0:44Route two: contact with blood and other body fluids. Ebola spreads this way, for example when infected blood gets into a cut.

0:54Route three: a jump from animals to people, called a zoonosis. Avian flu, or bird flu, can spread this way from infected birds.

1:05To slow a virus, put a barrier on its route. The barrier must match the route.

1:12For droplets and aerosols: masks, handwashing, staying home when sick, and vaccines.

1:20A vaccine trains the immune system, the body's defence, to recognize a virus, so fewer people catch it and pass it on.

1:28For blood and body fluids: isolation, keeping sick patients apart, and protective equipment for health workers.

1:37For bird flu: avoid sick or dead birds, and use protective equipment and handwashing when handling them.

1:44No barrier is perfect, but each one cuts the spread, so fewer people get sick.

1:51Viruses spread by different routes, so slow each one with a barrier that matches its route.