The Zika virus, first identified in Uganda in 1947, is transmitted by Aedes mosquitoes, the same type of mosquito that carries dengue fever, yellow fever, and chikungunya virus.
A mosquito bites an infected person and then passes those viruses to other people it bites.
Outbreaks did not occur outside of Africa until 2007, when it spread to the South Pacific.
The Zika disease had seen swift expansion between early 2015 and January 2016 throughout South America and Caribbean where babies with abnormally smaller heads due to Microcephaly were born.
Zika can spread through sex, usually after a person traveled to an area where Zika has broken out, got the virus, and gave the virus to a sex partner who did not travel. Infected women and men can both pass the virus to sex partners — even if they haven’t shown symptoms of infection. In addition, infected pregnant women can pass the virus on to their fetus.
Some studies have also shown the virus can be found in blood, semen, urine, and saliva of infected people, as well as in fluids in the eye.
The disease can cause fever, rash, joint pain, and redness in the whites of the eye (conjunctivitis, or pinkeye). But most people won’t know they have it.
There’s no treatment. The disease usually runs its course within a week or so.
There is no vaccine against Zika.
Zika causes microcephaly in babies born to infected pregnant women. Microcephaly stunts a baby’s head growth, causing devastating, sometimes fatal brain damage, and it can result in miscarriage or stillbirth.