Transmission

Through Mosquito Bites

Aedes aegypti mosquito

Aedes aegypti mosquito.

Dengue viruses are spread to people through the bites of infected Aedes species mosquitoes (Ae. aegypti or Ae. albopictus).  These are the same types of mosquitoes that spread Zika and chikungunya viruses.

  • These mosquitoes typically lay eggs near standing water in containers that hold water, like buckets, bowls, animal dishes, flower pots, and vases.
  • These mosquitoes prefer to bite people, and live both indoors and outdoors near people.
  • Mosquitoes that spread dengue, chikungunya, and Zika bite during the day and night.
  • Mosquitoes become infected when they bite a person infected with the virus. Infected mosquitoes can then spread the virus to other people through bites.
Aedes albopictus mosquito

Aedes albopictus mosquito.

From mother to child

  • A pregnant woman already infected with dengue can pass the virus to her fetus during pregnancy or around the time of birth.
  • To date, there has been one documented report of dengue spread through breast milk. Because of the benefits of breastfeeding, mothers are encouraged to breastfeed even in areas with risk of dengue.

Through infected blood, laboratory, or healthcare setting exposures

Rarely, dengue can be spread through blood transfusion, organ transplant, or through a needle stick injury.