Three Iowans infected with Zika

There are now three confirmed Zika cases in Iowa, state public health officials said Friday.

All three individuals infected with the virus are women over the age of 40 years old and are not pregnant, according to the Iowa Department of Public Health. The women had traveled to affected areas where the virus was present, including South and Central America as well as the Caribbean.

Zika is spread through mosquitoes as well as sexual contact with an individual who has already contracted the disease.

About 20 percent of people infected with Zika virus will become ill, according to the Iowa Department of Public Health. The most common symptoms of Zika are fever, rash, joint pain, or conjunctivitis. Other symptoms include muscle pain and headache.

There is also a possible link between Zika virus infection in pregnant women and subsequent birth defects, including microcephaly - where a baby's head is smaller than expected.

The Centers for Disease Control and Prevention said Friday that it has received reports of nine pregnant travelers with laboratory-confirmed Zika virus disease and another 10 reports that are under investigation.

Pregnancy outcomes among the nine confirmed cases included two early pregnancy losses, two elective terminations, and three live births - one infant had severe microcephaly. Another two pregnancies are continuing without known complications.

During a conference call with reporters, CDC Director Tom Frieden said there are still many unknowns about the virus such as if there's a phase of pregnancy where infection is a lower risk and if infants born without microcephaly will develop other health problems later in life.

CDC is working with other public health officials to monitor Zika virus transmission and potential links between Zika virus infection during pregnancy and birth defects.