Our children don't have to get smallpox shots any more because the disease no longer exists.

To them, the disease simply cannot exist - and therefore need not be fought.

But there will be no cure if we pretend the disease does not exist.

Sexual diseases existed, especially in the ports, all over Europe.

Though the disease existed for a few years before you arrived.

I say how I'm surprised all these diseases still exist in the world.

According to some, the disease has always existed only to be 'discovered' during the early 20th century.

There was a belief that the disease didn't exist because no one had seen it.

These kinds of meal have been banned but the disease still exists.