CDC has issued Zika-related travel and testing guidance for Brownsville, Cameron County, Texas, following reports from Texas public health officials of five cases spread locally by mosquitoes. This information suggests that there may be a risk of continued spread of Zika virus and therefore pregnant women are at some risk for Zika virus infection. CDC is designating the city of Brownsville as a Zika cautionary area (yellow area). Texas Department of State Health Services (TDSHS), Cameron County Health Department, Brownsville Health Department and CDC are working together to rapidly learn more about the extent of Zika virus transmission in Brownsville.