Zika cases in the U.S. topped 1,800 this week

Pregnant women are now advised to stay away from Florida's so-called Zika zone. There could be a new weapon in the fight against the virus: Federal authorities have approved testing of genetically modified mosquitoes designed to stop the spread of Zika by reducing the insect populations. Mutant male mosquitoes pass on a lethal gene to the females killing their offspring. Read more: CBS