The first local transmission of Zika virus in the United States has officially occurred, reports NPR. U.S. citizens have already contracted Zika, but became infected while traveling in foreign countries or by having unprotected sex with someone who did. Now, local mosquitos in a small part of Florida north of Miami appear to be transmitting the virus. "This morning we learned that four people in our state likely have the Zika virus as a result of a mosquito bite," said Florida Governor Rick Scott. "This means Florida has become the first state in our nation to have local transmission of the Zika virus."

This is a major development in what is quickly becoming a global health issue. Zika is already widespread in South and Central America and some parts of the Caribbean, but until today it had yet to reach the shores of the United States. According to the NPR report, transmission so far appears to be isolated to roughly one square mile north of downtown Miami.

Although serious, officials are less concerned about it becoming widespread in the United States due to the "presence of screens, air conditioning and higher standards of living," said the report. Still, the CDC has already asked two local blood banks to cease all activity until it can test every donation for the virus. The state has also started to enact "mosquito control efforts" to help stop the virus from spreading further.

According to the CDC, 1,658 cases of Zika have been reported in the United States so far. Although the virus is very dangerous to pregnant women due to the risk of severe birth defects, the average person will likely experience mild, flu-like symptoms at worst. Many people will never experience any symptoms, and wouldn't know they had it without being tested.