We start with a health alert. The tiny mosquito causing big concerns. New cases of a virus with no known cure being reported this morning in six states, and worries that it could become as rev lent in... See More
We start with a health alert. The tiny mosquito causing big concerns. New cases of a virus with no known cure being reported this morning in six states, and worries that it could become as rev lent in the U.S. As west nile. ABC's initial Franzen is here with more. Reporter: The little-known virus is just getting started in the U.S. The CDC has shown the number of cases for 2014 has surged past the U.S. Yearly average. Enough for health workers to issue travel advisories dealing with countries dealing with widespread outbreaks. New health concerns this morning as the spread of a mosquito-transmitted virus grows. For the first time, spreading to the northeast, with two confirmed cases, in Rhode Island. Health officials say there's no known cure or treatment. There's no vaccine for it. There's nothing else you can really due but avoid mosquito bites. Reporter: Easier said than done with mosquito season just getting started. There's been 41 reported cases. Florida the hardest hit. With cases recorded in north Carolina, Tennessee and Rhode Island. More than a dozen caribbean nations are dealing with an outbreak. Travelers from those countries, now bringing it to the U.S. Just slowly been picking its way around the world. And finally, it landed in the caribbean. Reporter: The symptoms begin three to seven days after the mosquito bite. And usually last about a week. Including fever, headache, muscle pain, rash and severe joint pain in hands and feet. The CDC says although there is concern over the latest cases, there's not an outbreak in the U.S. Health officials say Americans, especially those traveling abroad, need to watch for signs. Health officials say they are also monitoring other reports of people having similar symptoms in at least 12 states. And they also say they could expect a spike in cases this summer, as people traveling back and forth to the world cup games in Brazil return. A lot to look out for. Michelle, thank you.
This transcript has been automatically generated and may not be 100% accurate.