Thirty-one Americans have been diagnosed with a Zika infection. All were infected while they were traveling abroad, according to Anne Schuchat, principal deputy director at the U.S. Centers for Disease Control and Prevention. The cases have been diagnosed in 11 states and in Washington, D.C.
One person who tested positive for the virus is a pregnant woman living in New York City. Two others are pregnant women who live in Illinois, according to that state's Department of Public Health.
Despite the number of cases, these are still isolated instances. In the United States, it is a very different situation from the Zika epidemic in Brazil, where there were an estimated 1 million people infected by Zika by the end of 2015. Currently, people in the continental United States can only contract Zika if they travel to an area with a Zika epidemic.
Four Canadians have been infected with the Zika virus after traveling to affected countries, according to Canadian government health officials. Two of the infected Canadians are from the province of British Columbia and one each are from Alberta and Quebec. None are pregnant women. Some of the travel by infected Canadians was to Colombia and El Salvador, said Rebecca Gilman of the Canadian health department. Health officials did not say when they returned to Canada.
Zika virus has been linked to serious birth defects in babies whose mothers were pregnant when they became infected. The virus appears to cause microcephaly, a condition where the baby's head is smaller than normal and the brain has not developed normally.
The virus is also thought to be linked to an outbreak of Guillain-Barre syndrome, an autoimmune condition that causes paralysis.
The Zika virus is transmitted by bites by the Aedes species of mosquito and has been linked to microcephaly in thousands of babies in Brazil. There is no known vaccine or treatment. Aedes mosquitoes that can transmit the virus are found in all countries in the North and South American except Canada and Chile, according to the Pan American Health Organization.
