As public health officials in the U.S. gear up for the expected arrival of the Zika virus, the Centers for Disease Control has issued an updated map (as of March 2016) showing the occurrence of the two Aedes mosquitoes that transmit the disease.

Aedes aegypti, known as the yellowfever mosquito, has now been reported from 183 counties in 26 states and the District of Columbia. The Asian tiger mosquito, Aedes albopictus, has been documented in 1,241 counties in 40 states plus D.C. This does not mean that the mosquitoes are necessarily common in all of these states, it just means that they have been found to occur there. Some parts of the U.S. have well-established populations while other regions have very few of the mosquitoes present. To view the new range map, click here.

Aedes aegypti, for example, is a tropical mosquito and is common in the warmer southern and coastal U.S. Aedes albopictus can tolerate colder temperatures and so ranges farther north in the U.S., including into parts of New England (see Get to Know the Asian Tiger Mosquito!). This mosquito will be the one responsible for transmitting Zika virus in our area, if and when that happens.

Current Zika Cases Have Originated Outside of the U.S.

To date, there have been almost 1,000 reported cases of Zika virus in the continental U.S. All have occurred in people who picked up the disease when traveling to countries where Zika is common. There have no doubt been many more undocumented cases since most people don’t have any symptoms. In the continental U.S., there have not been any cases of direct Zika transmission that occurs when one of our Aedes mosquitoes bites a returning traveler that has the disease and then bites another individual, transferring the disease.

Zika virus is a very real possibility, even here in the Northeast (see Advance Warning! – Zika Virus Can Occur in New England). Health officials are cautiously planning and waiting to see what develops as the summer goes on. Plan on making mosquito repellent a part of your life and learn what you can do to eliminate breeding mosquitoes on your property (see Worried About Mosquitoes? for tips).

Photo Credit : CDC/ Journal of Medical Entomology