Wisconsin health officials reported today on the first Zika virus case in the state. The individual who tested positive is a woman who recently traveled to Honduras, where Zika-infected mosquitoes are present. There have been no locally-acquired cases of Zika virus infection in Wisconsin or in the continental United States.

Wisconsin map/National Atlas of the United States
Wisconsin map/National Atlas of the United States

“Wisconsin is one of the last states to have a confirmed case of Zika virus infection detected in a resident, but we have been actively preparing for the likelihood that this day would come,” said State Health Officer Karen McKeown.

Today in the US, only South Dakota, Wyoming, Idaho and Alaska have not reported any cases.

Related: North Dakota pregnant woman is state’s 1st Zika case

“Together with partners we have been working to prepare our Zika virus response plans. This includes testing more than 300 people who have traveled to countries with known Zika virus transmission, and monitoring for the presence of mosquitoes that may carry Zika virus. We will remain vigilant in our response to ensure the safety and health of all Wisconsinites, particularly pregnant women and unborn babies, who are most at risk.”

The Department of Health Services (DHS) has been working on this issue with the Centers for Disease Control and Prevention (CDC), local health departments, health care professionals, the Wisconsin State Lab of Hygiene, and the University of Wisconsin – Madison Entomology Department. Because Zika virus poses the greatest risk to pregnant women and their unborn babies, DHS has targeted outreach to health care providers caring for pregnant women, because an infected mother may pass the Zika virus to a baby during pregnancy. Zika virus may cause microcephaly in the infant, which is a medical condition in which the size of the head is smaller than normal because the brain has not developed properly.

About 80 percent of people who are infected with Zika virus do not have any symptoms. Illness may develop in 20 percent of infected people within 3 to 7 days after a bite from an infected mosquito. Symptoms are generally mild and can last for several days to a week. Common symptoms of Zika virus infection include fever, rash, joint pain, conjunctivitis (red eyes), muscle pain or headache. Serious complications are extremely rare. There is no medication to treat Zika virus disease and no vaccine is currently available.

Zika is typically transmitted to people by a bite from an infected mosquito, however, it can also be spread from mother to unborn child, through sexual contact, and through blood transfusions. According to DHS, surveillance has not identified mosquitoes that carry the Zika virus in Wisconsin.