The first mosquito-borne case of Zika has occurred in the US

For the first time, the Zika virus might have been transmitted from mosquitoes to humans inside the United States, according to Florida Governor Rick Scott. Scott confirmed that four cases under investigation in his state were not brought in from outside the country.

The four cases, which occurred in Miami-Cade and Broward Counties, were "the result of local transmission," and are "likely mosquito-borne," according to the Florida Department of Health. However, health officials have yet to locate mosquitoes infected with the virus, and have yet to rule out sexual transmission of the virus.

If the virus was transmitted by mosquito, it would mark the first time Zika has been transmitted in such a fashion in the United States. If a local...