Zika virus 6 months later.

On January 15, 2016, the Centers for Disease Control and Prevention advised pregnant women not to travel to areas where the Zika virus was spreading. Six months later, more than 60 countries or territories have reported new local transmission of Zika. By August 4, 2016, nearly 1700 cases of travel-associated Zika infection, including 479 in pregnant women, had been reported in the continental United States; Puerto Rico is experiencing rapid and extensive spread of the epidemic.¹ Florida has documented 5 symptomatic and 8 asymptomatic locally acquired Zika infections in a 6-block area north of downtown Miami. Comprehensive mosquito control efforts, including reduction of standing water, provision of repellants containing diethyltoluamide (DEET), and application of pyrethroid insecticides and larvicides using backpack sprayers and trucks to eliminate adult and larval forms of mosquitoes, were initiated on confirmation of the first cases. Persistent findings of Aedes aegypti mosquitoes led to a decision to also use aerial spraying with naled and larvicide within 3 days of documentation of the risk of ongoing Zika transmission.