The U.S. is unprepared for the growing threat of mosquito- and tick-borne viruses

Mosquitoes can carry viruses including dengue, malaria, chikungunya and Zika. They are a growing public health threat abroad and in the United States. (Rick Bowmer/AP)

In the 1970's and '80's, Aedes albopictus mosquitoes came to the U.S. through the used tire trade. These stowaway insects, also known as Asian tiger mosquitoes, can carry viruses like dengue, Zika and chikungunya. They quickly adapted to city life in the southern, eastern and western U.S.

Since then, due to globalization and climate change, insects and the diseases they carry are spreading more widely around the world.