In the first such case in California, a woman from San Diego was infected with Zika virus through sexual contact, health officials said Friday.
The woman, who became ill last month, hadn't traveled out of the country, but her partner had recently visited Colombia, which is one of more than 30 countries in the Americas reporting many cases of the disease. Both have recovered.
Zika virus, suspected of causing birth defects, is primarily transmitted to humans by mosquitoes. However, it can also be passed from person to person through sex.
As of Friday, there had been 22 cases of travel-associated Zika virus this year in California, according to the state health department. The most were in San Diego County, which had seven, followed by L.A. County with five.
Nationwide, 273 Americans have contracted Zika virus, the vast majority of whom had traveled to a country with an outbreak, according to the U.S. Centers for Disease Control and Prevention. Six of those cases were sexually transmitted, according to the agency.
For most people, Zika virus is a mild illness, with symptoms lasting less than a week.
But there's increasing evidence that pregnant women who contract the illness can infect their fetuses, causing birth defects. Pregnant women have been advised not to travel to countries with outbreaks.
If their partners have traveled to a country with an outbreak, pregnant women are also advised to abstain from sex or to use condoms to prevent the spread of the disease.
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