Many areas in the United States have the type of mosquitoes that can spread Zika virus. These mosquitoes bite during the day and night. Zika can also be passed through sex from a person who has Zika to his or her sex partners.
Zika infection during pregnancy can cause a serious birth defect called microcephaly that is a sign of incomplete brain development. Doctors have also found other problems in pregnancies and among fetuses and infants infected with Zika virus before birth. If you are pregnant and have a partner who lives in or has traveled to an area with risk of Zika, do not have sex, or use condoms the right way, every time, during your pregnancy.
If you must travel to one of these areas, talk to your healthcare provider first and strictly follow steps to prevent mosquito bites and sexual transmission during your trip. See CDC’s domestic guidance for information on travel within the continental US and Hawaii.
During the first week of infection, Zika virus can be found in a person’s blood and can pass from an infected person to a mosquito through mosquito bites. An infected mosquito can then spread the virus to other people.