Texas has seen the worst annual spike of dengue fever, a mosquito-borne illness that can be fatal, in more than 20 years, according to the Texas Department of State Health Services. The state also saw its first report of a locally acquired — meaning a confirmed case in an individual who did not recently travel to an area considered at risk for the disease — case of dengue fever this year in a resident of Cameron County,

"Locally acquired" means that the people infected have no history of traveling to an area of the world where dengue normally spreads.