Zika may have arrived in thecontinental United States by other means than travel.

Stat reported that two adjacent Florida counties,Broward and Miami-Dade, are the locations of four new cases of Zikathat thus far have not been attributed to travel outside the UnitedStates but may be caused by the bites of infected mosquitoes inFlorida.

This summer has brought much trepidation surrounding the spreadof the Zika virus, forcing Congress to consider significant fundingto combat the disease. Upon finding out about the presence of thevirus in Florida, Senate Democratic Leader Harry Reid called forCongress to return to Capitol Hill and figure out next steps. In atweet, Reid said, "Zika is public health emergencythat requires immediate bipartisan action. Americans can’t affordto wait until Congress' vacation is over."

Prior to Reid's call to action, Democrats pushed for $1.9billion in funding to fight Zika, but were held off bycongressional Republicans for several months. Eventually, the GOPagreed to $1.1 billion in financial assistance, but the legislationcontained cuts to Planned Parenthood, Obamcare, and Ebola funds inorder to provide the necessary resources for Zika. Democrats werenone too thrilled and ultimately nixed the measure, leavingRepublicans to balk at further neogotiations.

Congress adjourned for summer recess on July 15 with no plan inplace for battling Zika. Should Congressional members ignore Reid'srequest, they'll remain on break until September 6.

While sexual transmission as thecause of the new cases has not yet been ruled out, health officialsare investigating and so far it appears that they could be due to alocal outbreak rather than to other means of infection.

The report said that, despite 1,400 cases already reportedwithin the continental United States, uptill now nearly all were acquired via travel outside the country.Fifteen were sexually transmitted, and infection in a laboratorycaused a sixteenth case. But these four so far appear to have beencaused by direct infection rather than by other means.

The more people who return to the United States with theinfection, the more the odds increase that the disease will end upspreading, since a local mosquito biting an infected person couldthen become infectious and transmit the disease through futurebites.

That said, a wide outbreak in the continental United States isnot expected, because populations are not as dense in the UnitedStates and there is much broader use of both screens and airconditioning than in the Caribbean and Latin America, where thedisease has experienced greater spread.

Florida is considered a high-risk area for transmission of thedisease, which is carried by Aedes aegypti mosquitoes. The statehas been one of the few continental U.S. locations to see thespread of similar diseases, such as dengue and chikungunya. Andthere are already more than 380 reported cases of Zika in Florida,although they are travel related. Adults, except for high-riskindividuals, usually only experience a mild illness, but 53 ofthose cases are pregnant women; Zika presents particular birthdefect risks to the fetus.

Residents of the two counties who live near the newly reportedcases are being tested for the presence of the virus, and officialsare also trapping mosquitoes to test them as well — though they sayin the report that, “depending on the number of mosquitoes, thatcould be like looking for a needle in a haystack.”