A National Institutes of Health official says the Zika virus could "hang around" the United States for a year or two. Dr. Anthony Fauci told ABC's "This Week" on Sunday that other Gulf Coast states, besides Florida, are most vulnerable to the spread of the disease. Mosquito-borne Zika cases have been found in two neighborhoods of Miami-Dade County. They are the first areas on the U.S. mainland where health officials determined mosquitoes were transmitting Zika. Meanwhile the mayor of Miami Beach - where five mosquito-borne cases have been found - says city workers are doing everything in their power to go after mosquitoes in the popular tourist destination. Mayor Philip Levine told New York radio station AM 970 that Miami Beach is running smoothly, despite the Zika concerns.