The Zika virus is a virus transmitted through an Aedes mosquito bite. Most commonly, these mosquitoes become infected when they bite an infected individual. The virus is then spread to other people through subsequent bites. A few cases of Zika virus have been transmitted through sexual intercourse, blood transfusion, or from an infected pregnant mother to her baby, but more research is required to fully understand these processes. While outbreaks of Zika virus have mostly occurred in regions of Africa and Asia, a growing number of cases are occurring in parts of South America, Mexico, and the Caribbean.