As Zika spreads in Puerto Rico, these 10 U.S. cities could be next
Those who believe that Americans are far-removed from the threat of Zika are in for a wake-up call. Puerto Rican blood banks have seen a steady rise in the number of Zika-infected blood units collected — a clear sign of how quickly the disease is spreading in the area, Centers for Disease Control and Prevention Director Tom Frieden told reporters Friday.