Tom Frieden

New, unfamiliar, and mysterious threats to our health are scary. At the Centers for Disease Control and Prevention - where we identify, on average, one new health threat each year - we work around the clock with an approach that prioritizes finding out what we need to know as fast as we can to protect Americans.

Zika is spread by mosquitos. They are tough to control. It will bite four or five people at one blood meal. They can breed in the amount of water it takes to fill up a bottle cap or, theoretically, even a drop of water. You have to get rid of maybe 90% of them or more before you protect people.

I've had to change careers several times. Sometimes because my interests changed. Sometimes because all bridges have been burned beyond recognition, sometimes because I desperately needed money. And sometimes just because I hated everyone in my old career or they hated me.

To ask questions can become the laziest and wobbliest occupation of a mind, but when you must yourself answer the problem that you have posed, you will meditate your question with care and frame it with precision.