As some world-class athletes pass up the opportunity of a lifetime to compete at the Rio Olympics due to worries about the Zika virus, the concerns and fears now are striking closer to home. Zika-carrying mosquitoes have come to America.

Florida Gov. Rick Scott announced this morning that 10 more people in the Miami area, for a total of 14, appear to have contracted the virus from mosquitoes in the U.S.

To date, more than 1,300 people in America reportedly have been infected with the virus either through travel outside the country or sexual contact with a partner who had traveled.

As worrisome as that has been, it is easy to discount the threat: As long as I don’t travel to the wrong places or have sexual contact with anyone who has, I am perfectly safe.

Well, the “battlefield” just changed.

Top Florida health officials announced Friday that mosquitoes likely infected four people in Miami with the Zika virus. These were the first documented cases of mosquito-borne transmission in the continental United States.

In announcing 10 more cases today, Scott asked Monday for a federal emergency response team to help contain the spread of the virus in the U.S., the Associated Press reported.

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An emergency response team from the Centers for Disease Control and Prevention will help Florida officials in their investigation, sample collection, and mosquito control efforts, AP reported. The White House said the team would be deployed to Florida “in short order.”

Officials in Florida are testing mosquitoes near downtown Miami, where the four patients live, and are offering tests to residents of the area.

As we have discussed before in The Daily Signal, Zika symptoms generally are so mild that those infected may be unaware of it. And even those with more acute symptoms generally recover easily.

But the virus also can cause neurological disorders and brain damage in babies born to infected mothers. This threat is not insignificant, as the hundreds of infants with microcephaly (abnormally small heads) in Brazil, Colombia, and elsewhere in Latin America attest.

This is a threat against our most vulnerable, the unborn.

Public health experts agree that as of today, the best strategy against this scourge is mosquito control (spraying as well as draining standing water where mosquitoes breed) and use of repellants and netting or protective clothing.

Scientists continue to fast-track efforts to develop both protective vaccines and post-infection treatments, and although they are close, they are not yet there.

Anyone with questions or worries should see their physician to be tested. The most likely transmission mode is still travel to one of the heavily infected areas or sexual contact with a partner who has had such travel. But keeping an eye out is wise.

The Summer Games in Rio will remain ground zero for this fight as summer crowds swell in Brazil.

The announcements in Florida are a stark reminder that insects respect no political boundaries. And as summer progresses in the U.S., Americans need to be vigilant and wise about the threat Zika presents here.