What is the Zika virus and how does it spread?

The Zika virus is a mosquito-borne illness predominately in Central and South America, but outbreaks have occurred in Africa, Southeast Asia, the Pacific Islands and the Americas, according to the Centers for Disease Control and Prevention.

The virus can cause fever, rash, joint pain or red eyes. No vaccines or medications are available to treat Zika infections. The need for hospitalization is uncommon and deaths are rare.

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There are no known locally transmitted instances of the virus in the United States, but cases have been reported in returning travelers, the CDC said. And in Hawaii over the weekend, a baby born with microcephaly (a birth defect that causes a small head and brain damage) was determined to have contracted the disease.

In that case, the mother had likely contracted Zika virus when she was living in Brazil in May 2015 and her baby acquired it in the womb, said the Hawaii State Health Department on Saturday. Neither the mother nor baby is infectious, health officials said.

The risk of pregnant mothers transmitting the virus to their babies caused the CDC to issue an alert for women traveling to Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela and Puerto Rico. Brazil’s health ministry said pregnant women should consult their doctors before traveling to Brazil.

If travelers are headed to countries where the virus is present, the CDC recommends wearing long sleeves and pants, staying in places that have air conditioning, screened windows and doors, and applying insect repellents with DEET.

The virus is spread by Aedes aegypti mosquitoes, which typically live in tropical and subtropical regions in the world. They also are known to spread dengue fever, chikungunya and yellow fever.

A mosquito that bites an infected person can then spread the disease by biting other people.

Health officials in places like the Caribbean were working to educate residents on the virus and on emptying outdoor water storage containers, flower pots, tires or other places where water could collect to reduce breeding grounds for the mosquitoes.