Through mosquito bites
Zika virus is transmitted to people primarily through the bite of an infected Aedes species mosquito. These are the same mosquitoes that spread dengue and chikungunya viruses.
These mosquitoes typically lay eggs in and near standing water in things like buckets, bowls, animal dishes, flower pots, and vases. They prefer to bite people, and live indoors and outdoors near people.
Mosquitoes that spread chikungunya, dengue, and Zika are aggressive daytime biters. They can also bite at night.
Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites.
Rarely, from mother to child
A mother already infected with Zika virus near the time of delivery can pass on the virus to her newborn around the time of birth, but this is rare.
It is possible that Zika virus could be passed from mother to fetus during pregnancy. This mode of transmission is being investigated.
To date, there are no reports of infants getting Zika virus through breastfeeding. Because of the benefits of breastfeeding, mothers are encouraged to breastfeed even in areas where Zika virus is found.
Through infected blood or sexual contact
Spread of the virus through blood transfusion and sexual contact have been reported.