Zika is carried by a very specific type of mosquito, the
Aedes species.
How is Zika transmitted?
Zika is primarily transmitted through the bite of infected Aedes mosquitoes, the same mosquitoes that spread Chikungunya and dengue. These mosquitoes are aggressive daytime biters and they can also bite at night. Mosquitoes become infected when they bite a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites. It can also be transmitted from a pregnant mother to her baby during pregnancy or around the time of birth. We are studying how some mothers can pass the virus to their babies.
http://www.cdc.gov/zika/disease-qa.html
Also from the CDC:
http://www.cdc.gov/chikungunya/resources/vector-control.html
Zika likely not as devastating in the U.S.
As concerned as public health officials are about Zika, they highly doubt the virus will be as devastating in the United States as it has been in Brazil.
"You never say never, but I'm fairly sure we're not going to have a problem of great magnitude in this country," said Dr. Anthony Fauci, head of the National Institutes for Allergies and Infectious Diseases at the National Institutes of Health. "There will be some unfortunate cases, but nothing of the magnitude that the poor Brazilians are going through," he added.
So far, there have been about 20 cases in the continental United States, according to Fauci. All of those patients had traveled abroad to Brazil or other affected areas. The disease has
not spread beyond those travelers, according to the CDC. Earlier this month,
a baby in Hawaii was born with microcephaly. The mother had spent part of her pregnancy in Brazil.
Experts have several reasons for believing the spread of Zika in the United States will be much more limited than in Brazil. First, a similar virus,
dengue, has never spread much in the United States. Over the years, nearly all cases have been among travelers, with transmission within the United States happening only rarely.
Experts believe cooler weather is a big part of the reason, as the mosquitoes that spread viruses such as dengue and Zika prefer hotter climates. "I'm very worried about tropical areas of the United States, such as American Samoa, Puerto Rico and the U.S. Virgin Islands," Petersen added.
The experts believe living conditions in the United States will also slow the spread of the disease, which occurs when a mosquito bites an infected human and then bites someone else.
Americans tend to live farther apart than people do in Brazil, Petersen noted. Also, air conditioning is much more common in the United States, and the mosquitos dislike cool air. And mosquito control measures in warm places such as Texas and Florida are very effective, Weaver added.
http://www.cnn.com/2016/01/26/health/halting-spread-of-zika-united-states/