Zika virus is spread to people through mosquito bites. The most common symptoms of Zika virus disease are fever, rash, joint pain, and conjunctivitis (red eyes). The illness is usually mild with symptoms lasting from several days to a week. Severe disease requiring hospitalization is uncommon. Eighty percent of patients infected with Zika are asymptomatic, according to the CDC. Those people who do present symptoms may experience fever, rash, joint pain or conjunctivitis. Severe cases may require hospitalization, but no deaths have been linked directly to Zika. Most patients who exhibit symptoms do so for several days to a week.