ROCKLAND COUNTY, N.Y. (CBSNewYork) — Officials in Rockland County have confirmed their first case of the Zika virus.

Zika is spread by mosquitoes and in most people causes no more than mild illness. But there’s been mounting evidence linking Zika infection in pregnant women to a birth defect called microcephaly, in which a newborn’s head is unusually small and the brain may not develop properly.

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Rockland County Health Commissioner Dr. Patricia Ruppert said the woman is not pregnant.

“We have a female, a resident of Rockland County, who traveled to South America, and within a few days of returning here had symptoms of Zika virus presented to her provider who contacted us,” Ruppert said. “We arranged for testing to be performed by the state lab in Albany and the results were positive.”

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Ruppert said the mosquito that transmits the virus is not found here. A cousin of the mosquito does show up in the Hudson Valley, but not until late June or early July.

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.

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According to the state Department of Health, there are 11 cases of Zika in New York: three in Suffolk County; one in Nassau County; one in Rockland County; one in Westchester County; one in Monroe County; and one in Orange County.