The virus was first identified in Uganda in 1947, and has caused outbreaks in Africa, Southeast Asia and on several Pacific Islands. It is believed to have crossed the Pacific and been introduced into Brazil in 2014, where its largest outbreak ever has occurred. Zika has been spreading rapidly through the Western hemisphere since then.
2 What health risks does Zika pose?
Zika poses a significant risk for pregnant women. There is strong evidence of a link between the Zika virus and a birth defect called microcephaly in which babies are born with undersized brains and skulls, according to the Centers for Disease Control and Prevention. Brazil’s health ministry has reported several thousand cases of suspected Zika-related microcephaly since October 2015.
The CDC has warned pregnant women to avoid travel to 24 countries and territories, mostly in Central and South America and the Caribbean. It has also urged women who are trying to become pregnant to talk with their doctors about the planned trip, and to protect themselves from mosquitoes if they do go.
Pregnant women are likely most at risk during their first trimester, when brain development is occurring, the CDC says, but adds there is evidence the risk continues into the second trimester as well.
Pregnant women who have already traveled to a country where Zika is circulating should be evaluated by their doctors for infection, the CDC says. It’s possible that the baby may be affected even if the mother doesn’t develop symptoms herself. Women who test positive for Zika should be given regular ultrasounds to monitor the development of their babies, the CDC says.
Also of concern to international health authorities is a suspected link between Zika and an increase in the number of cases of Guillain-Barre syndrome, a rare disorder in which the body’s immune system attacks nerve cells. It can cause temporary paralysis that can last for weeks. The CDC is investigating the possible link between Zika and Guillain-Barre syndrome.
3 What is the link between Zika and microcephaly?
Scientists believe that infected pregnant women pass the virus to their unborn babies through the placenta, and that the virus then damages their brain development. Tests in CDC labs found the virus in the placentas of two fetuses that had had microcephaly and miscarried, and in the brains of two full-term babies who were born with microcephaly and died. But the tests didn’t show how the virus causes the birth defects. More studies are under way or planned to find that out, researchers say.
Researchers are also studying the rise in cases of microcephaly in Brazil to try to determine how many of them are due to Zika rather than other factors.
4 How can I protect myself from Zika?
There is no vaccine for Zika. Do everything you can to protect yourself from mosquito bites. Aedes mosquitoes are very aggressive and bite during the day, often around the ankles and knees. Wear mosquito repellent containing DEET or other ingredients that provide long lasting protection. Wear long-sleeved clothing when you can.
Aedes aegypti breed in small pools of water, often those in front yards and backyards of homes: flower pots, tires, even tiny pockets of water in childrens’ toys. Remove as many of these containers as you can from the area around your home.