80% of people with Zika virus infection will not show any symptoms and may not be aware they have been infected. If symptoms occur, they may include fever, rash, joint pain, and conjunctivitis. The infection is usually mild and lasts for a week or less.
In a minority of pregnancies, Zika virus infection has been shown to cause microcephaly (a birth defect) and may be associated with other complications in pregnancy. The available evidence indicates that there is no risk to subsequent pregnancies if a woman waits 2 months after Zika virus infection to conceive a child. It appears that, on very rare occasions, Zika virus infection can result in an abnormal immune response directed at nerve tissue resulting in Guillan-Barré syndrome (GBS) or acute disseminated myelitis (ADEM) and perhaps other neurologic conditions.
There is no specific treatment or vaccine for Zika virus at this time.