There are more than 200 types of mosquitoes in the U.S. Of those, about 12 types are capable of transmitting disease. The diseases that have been found in the United States include Dengue, chikungunya, Zika virus, and Malaria; outbreaks occurred in Florida, Texas, Puerto Rico, Hawaii, and the U.S. Virgin Islands. Most malaria cases reported were in travelers returning from tropical regions.