As of May 2016, the Zika virus disease and Zika virus congenital infection are nationally notifiable conditions. The Center for Disease Control (CDC) and the World Health Organization(WHO) report 503 travel-associated cases with 48 of those in pregnant women, 10 sexually transmitted and 1 with Guillain-Barré syndrome. These numbers only tell part of the story that is being told in the news as of lately.
This map from the Centers for Disease Control shows the distribution of Laboratory-confirmed Zika virus disease cases reported by state or territory.
The CDC and the WHO warn of the main transmission methods including:
- Mosquito bites – Zika virus is transmitted to people primarily through the bite of an infected Aedes species mosquito. These mosquitoes typically lay eggs in and near standing water in things like buckets, bowls, animal dishes, flower pots and vases. They prefer to bite people, and live indoors and outdoors near people. Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites.
- Pregnant Women to Child – A pregnant woman can pass Zika virus to her fetus during pregnancy. Zika is a cause of microcephaly and other severe fetal brain defects including Guillain-Barré syndrome. To date(May 2016), there are no reports of infants getting Zika virus through breastfeeding.
- Sexual Transmission – Zika virus can be spread by a man to his sex partners. The virus is present in semen longer than in blood so condoms should be used for at least 6 months after exposure.
- Blood Transfusion – As of February, 1, 2016, there have not been any confirmed blood transfusion transmission cases in the United States. Brazil has has several reported cases of this transmission type but those are being investigated.