Zika virus area set to expand in the future

Robert C. Reiner Jr., an assistant professor in the IU School of Public Health-Bloomington, studies the spread of mosquito-borne illnesses, including Zika.

He said the mosquitoes that transmit the virus -- the yellow fever mosquito, or Aedes aegypti, and the tiger mosquito, or Aedes albopictus -- have recently expanded their range to include much of the southern United States. And while a Zika outbreak in the U.S. is unlikely at this time, the spread of the disease bears watching.

“It’s not a risk today,” he said, “but five years from now it could become a bigger risk if the mosquitoes continue to establish a larger range.”

Reiner said Zika has not been well-studied compared to better-known illnesses transmitted by the same species of mosquitoes, such as dengue and yellow fever. While researchers are working to develop vaccines, he said, the immediate way to limit Zika’s spread is to focus on mosquito populations.

“What is needed is more mosquito control and educating people on preventative methods such as removing items that can collect water and harbor mosquito larvae,” he said.

Where has Zika virus been found?

  • Prior to 2015, Zika virus outbreaks have occurred in areas of Africa, Southeast Asia, and the Pacific Islands.
  • In May 2015, the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus infections in Brazil.
  • Currently, outbreaks are occurring in many countries.
  • Zika virus will continue to spread and it will be difficult to determine how the virus will spread over time.

Zika in the United States and its territories:

  • No locally transmitted Zika cases have been reported in the continental United States, but cases have been reported in returning travelers.
  • Locally transmitted Zika virus has been reported in the Commonwealth of Puerto Rico.
  • With the recent outbreaks, the number of Zika cases among travelers visiting or returning to the United States will likely increase.
  • These imported cases could result in local spread of the virus in some areas of the United States.

Countries and territories with active Zika virus transmission (as of February 3, 2016):

Zika Map


  • Barbados
  • Bolivia
  • Brazil
  • Colombia
  • Commonwealth of Puerto Rico, US territory
  • Costa Rica
  • Curacao
  • Dominican Republic
  • Ecuador
  • El Salvador
  • French Guiana
  • Guadeloupe
  • Guatemala
  • Guyana
  • Haiti
  • Honduras
  • Martinique
  • Mexico
  • Nicaragua
  • Panama
  • Paraguay
  • Saint Martin
  • Suriname
  • U.S. Virgin Islands
  • Venezuela


  • American Samoa
  • Samoa


  • Cape Verde