What we know
Zika is spread mostly by the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus). These mosquitoes bite during the day and night.
Zika can be passed from a pregnant woman to her fetus. Infection during pregnancy can cause certain birth defects.
There is no vaccine or medicine for Zika.
Local mosquito-borne Zika virus transmission has been reported in the continental United States. Learn more.