Twin Cities blood banks are taking steps to prevent the Zika virus from entering the region's blood supply, another sign that health officials are monitoring the exotic disease closely.
Although health officials stress that the risk of Zika transmission is low in Minnesota, both Memorial Blood Centers and the Minnesota Region of the American Red Cross will ask people who have traveled to Zika-infected regions to delay blood donations until they have been on American soil for at least four weeks.
Also this week, the list of infected countries grew to 30. Jamaica and Tonga, an island nation in the South Pacific, were identified by the U.S. Centers for Disease Control as countries to be avoided by pregnant women or those trying to become pregnant.
Zika has been linked to cases of microcephaly, a birth defect that causes abnormally small heads. It is spread primarily through mosquito species that are common in tropical areas. Most people who contract the virus never develop symptoms, which can include rash and joint pain, and most never require hospital treatment.
Most of the Zika cases in the United States, including two so far in Minnesota since 2014, have been linked to travelers returning from infected areas internationally.
Still, the CDC has not ruled out the possibility that the Zika virus could spread within the United States. That most likely could occur in southern regions where the mosquito responsible for Zika transmission, Aedes aegypti, has been found. And a Texas case investigated by the CDC showed this week that Zika can be transmitted sexually. The Texas case is actually the third to indicate that sexual transmission is possible, but researchers remain unsure how much risk sexual contact poses.
Which mosquitoes?
The recent spread of Zika, which hadn't even reached the Western Hemisphere until last year, has triggered international anxiety and a string of unanswered questions.
But for Minnesota, authorities say, the risk of transmission is low.