Liz Szabo

USA TODAY





A Minnesota woman has tested positive for the Zika virus after traveling to Central America, state health officials announced Wednesday.

About a dozen Americans in a handful of states have been diagnosed with Zika after visiting outbreak zones, but there is no evidence the virus, which is linked to an outbreak of birth defects in Brazil, is spreading in the USA. The virus doesn't spread from person to person, like the flu. It's spread by mosquitoes, like malaria and West Nile Virus.

The mosquito species that is known to spread Zika, the Aedes, doesn't live in Minnesota, making it unlikely the disease will spread in that state.

The new case was diagnosed in a woman in her 60s from Anoka County, Minn., according to the Minnesota Department of Health. Her symptoms began Jan. 1, after she returned from Honduras. She was not hospitalized and is expected to make a full recovery, health officials said.

About 80% of people infected with Zika virus have no symptoms at all, according to the World Health Organization. Those who do become ill tend to have mild symptoms, including a low fever, rash, joint pain, headache and pink eye.

“Zika virus is not a health threat for people in Minnesota, but it is a reminder that anyone traveling to a different part of the world should be mindful of the health issues present in that region,” said Minnesota Department of Health Commissioner Ed Ehlinger. “Since some regions where Zika is circulating are popular destinations for Minnesota travelers in the winter, we expected we might see cases of Zika in the state.”

The USA has had sporadic cases of Zika virus in travelers in the past; none of those cases caused outbreaks. The Centers for Disease Control and Prevention diagnosed 14 returning travelers with Zika from 2007 to 2014.

Some experts note the real number of travelers who've been infected with Zika is unknown.

"Remember, for every case of imported Zika that’s detected, there are at least four others that are asymptomatic and maybe another dozen that are just not diagnosed," said Peter Hotez, dean of National School of Tropical Medicine at Baylor College of Medicine. "Every day, there could be dozens of people coming into the U.S. carrying Zika virus, maybe more."

Mosquitoes are inactive during cold weather. In the spring, the risk increases that American mosquitoes could bite travelers returning from Latin America, Hotez said.

Five things to know about the Zika virus

Zika virus has been known in Africa since 1947, but was first diagnosed in the Western Hemisphere in May in Brazil. Since then, it has spread to 20 countries, in addition to Puerto Rico and the U.S. Virgin Islands.

The CDC has issued a travel alert, warning pregnant women not to travel to areas with outbreaks.That's because Zika virus is linked to a sharp increase in a type of birth defect, called microcephaly, in Brazil. Babies born with microcephaly have small skulls and incomplete brain development and are at high risk for developmental disabilities.

There are no treatments or vaccines for Zika virus.

Travelers to places with Zika outbreaks should stay only in buildings with window screens. People should wear long sleeves and pants when outside and use mosquito repellent that contains DEET, the Minnesota Health Department said.

Experts: USA must prepare now for Zika virus