Most people who become infected with the Zika virus do not get sick and may not even realize they have it. Symptoms that do occur tend to be mild and include rash, headache, red eyes, fever and joint pain, appearing 3-12 days after the person has been bitten. These symptoms can last for a few days up until about a week. However, for pregnant women, the risks can be far greater, as it has been shown that a Zika infection during pregnancy may cause birth defects.