Cuba on Thursday announced its sixth imported Zika case, a pregnant Cuban doctor who arrived on the island on March 15 from the northwestern Venezuelan state of Lara, the Public Health Ministry said in a statement published in the local press.

The case is the first on the Caribbean island involving a pregnant woman with Zika, a virus spread by the Aedes aegypti mosquito that is linked to a serious birth defect of the brain known as microcephaly and other poor pregnancy outcomes.

The 32-year-old patient, a resident of the western province of Artemisa, was tested because she was 19 weeks pregnant and had arrived from an area with a risk of transmission of the disease, even though she had no symptoms, the ministry said.

The Pedro Kouri Tropical Medicine Institute in Havana confirmed the positive result on Tuesday.

The U.S. Centers for Disease Control and Prevention issued a Zika alert for Cuba last Saturday, a day before President Barack Obama arrived on the Communist-ruled island for a historic three-day visit, urging travelers to "practice enhanced precautions."

It issued that alert, the second of three levels of travel notices issued by the CDC, four days after Cuba confirmed the first case of local transmission of the Zika virus. EFE