What you need to know about South Florida Zika scare

The Food and Drug Administration asked two South Florida counties — Miami-Dade and Broward — to immediately halt blood donations as what looks like four cases of locally transmitted, mosquito-borne Zika virus are investigated. Hari Sreenivasan talks with Dr. Anthony Fauci, National Institutes of Health, about the virus, which can cause birth defects. Fauci says the FDA is taking “prudent” steps.