This is why infected animals must be kept away from the rest.

Could your space friends send an infected animal by rocket ship for us to study?

"Between us, we'll cure those infected animals if earth science knows how!"

Human infection usually results from contact with infected animals or their products.

People get it from the bite of an infected animal.

Experts say it is difficult to tell the difference between infected animals and healthy ones.

The more infected animals around, the greater the risk of an outbreak in people.

However, exposure does not have to be directly from an infected animal.

All told, around half a million infected animals entered the food chain.

The epidemic began with the consumption of an infected animal.