Zika has now been declared a global public health emergency. Cases of the mosquito-borne virus are being discovered in the United States among those who have traveled to countries where the disease is prevalent. Dr. John Brownstein, Chief Innovation Officer at Boston Children's Hospital, is creator of HealthMap. It's a website that tracks illnesses, including Zika, as they pop up around the globe. Brownstein spoke with WGBH All Things Considered host Barbara Howard.

You can view the HealthMap website here