Two babies in California were born with microcephaly after their mothers were infected with Zika virus, state health officials said Thursday.
The mothers had traveled to countries with outbreaks of the illness before becoming infected. Officials would not release any more information about the women or the babies.
"This is a sobering reminder for Californians that Zika can cause serious harm to a developing fetus," said Dr. Karen Smith, director of the California Department of Public Health.
Nationwide, 13 babies had been born with Zika-related birth defects as of July 21, according to the U.S. Centers for Disease Control and Prevention.
When an unusually high number of babies in Brazil were born with microcephaly last year, health experts began to suspect Zika virus. The mosquito-borne illness was declared an international public health emergency in February.
Outbreaks of the virus have since spread to dozens of countries in the Americas. The CDC has warned pregnant women not to travel to infected areas.
Just last week, mosquitoes began to spread the virus in a region of Miami, prompting the CDC to issue a travel advisory for pregnant women not to travel to that neighborhood — the first ever travel warning within the continental United States.
More than 1,600 people in the United States have become infected with Zika virus this year, almost all of whom traveled to countries with outbreaks. There have been 114 travel-related infections in California, with the most in L.A. County with 24 and San Diego County with 23.
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