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Zika Virus and Pregnancy

​This is a special notice for women who are pregnant or may become pregnant soon and are planning to visit a place where Zika virus outbreaks have been seen.

Zika virus is a germ that is spread to people through mosquito bites. Outbreaks of Zika have occurred in Africa and in South America, Central America, the Pacific Islands and the Caribbean. Specific places where Zika cases have been seen include Brazil, Barbados, Cape Verde, Colombia, El Salvador, Guadeloupe, Haiti, Honduras and Puerto Rico. It is likely that outbreaks will spread to new countries. For complete, up-to-date information on where Zika virus has been found, visit: or ask your doctor.

Who is at risk of being infected?

Anyone who is living in or traveling to an area where Zika virus is found can be infected with the virus. For most people, Zika virus does not cause serious illness.  The major reason we worry about Zika virus is that cases of microcephaly (small head and brain size) and other poor pregnancy outcomes have been reported in babies of mothers who had the virus while pregnant. More studies are planned to tell us about the risks of Zika virus infection during pregnancy. But for now, US health officials recommend that:
  • Pregnant women in any trimester should consider postponing travel to the areas where Zika virus has been seen.
  • Pregnant women who do travel to one of these areas should talk to their health care provider. In addition, they should take extra care to  avoid mosquito bites during the trip.
  • Women trying to become pregnant should talk to their healthcare provider before traveling to these areas and should avoid mosquito bites during the trip.

How does Zika virus spread?

Zika virus is spread to people mainly through the bite of an infected Aedes species mosquito. 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. These mosquitoes typically lay eggs in and near standing water in things like buckets, bowls, animal dishes, flower pots and vases. They are daytime biters. 

​Zika virus can also be spread by an infected man or woman to his/her sex partners. An infected person can transmit the virus before, during and after symptoms develop. A man or woman who lives or has traveled to an area with ongoing Zika cases and who has a pregnant partner should use condoms or avoid having sex during the pregnancy.

The Zika virus can be spread from mother to child during pregnancy or around the time of birth. A mother already infected with the virus near the time of delivery can pass on the virus to her newborn around the time of birth. Adverse pregnancy and infant outcomes are associated with Zika virus infection during pregnancy. There are currently no reports of infants getting Zika virus through breastfeeding. In theory, Zika virus could be spread through blood transfusion. However, to date, there are no known reports of this.

What are the symptoms of Zika virus?

About 1 in 5 people infected with Zika virus may develop symptoms. The most common symptoms are fever, rash, joint pain, and red eye. The illness is usually mild with symptoms lasting from several days to a week. Severe disease requiring hospitalization is uncommon.

How is Zika virus diagnosed?

If you develop the symptoms described above and have recently traveled to areas with Zika outbreaks, see your healthcare provider. Your healthcare provider may order blood tests to look for Zika.

How is Zika virus treated?

There is currently no specific treatment for Zika virus. Proper care can help relieve symptoms, including getting plenty of rest, drinking fluids to prevent dehydration, and medication to reduce fever and pain, including acetaminophen, or paracetamol. Aspirin, ibuprofen, naproxen and other non- steroidal anti-inflammatory drugs (NSAIDs) should be avoided until dengue can be ruled out to reduce the risk of bleeding.

How can Zika virus be prevented?

There is no vaccine to prevent Zika. If you are a person infected with Zika, prevent sexual transmission of Zika by using condoms or not having sex. Travelers can avoid infection by taking steps to prevent mosquito bites:

Prevent Mosquito Bites

While outdoors in an area with mosquitoes: 
  • Use a mosquito repellent. Repellents approved by the EPA include those containing DEET, oil of lemon eucalyptus, Picaridin or IR3535. Read the directions on the product label to find out about precautions that need to be taken and how long the product is effective.
  • If you use a product containing DEET, do not use concentrations of more than 30% DEET. Apply DEET to exposed skin (not eyes or mouth) and on clothes, but do not use on open cuts or wounds. Do not apply underneath clothes.
  • Do not let children apply repellents to themselves. Apply the repellent to your hands and rub it on the child. Do not apply repellents to children's eyes, mouth, or hands and use cautiously around ears. Do not apply DEET on infants (mosquito netting can be used over infant carriers) or oil of lemon eucalyptus on children under 3 years of age.
  • When weather permits, wear protective clothing such as long sleeved shirts, long pants, and socks.
  • Use air conditioning or window/door screens to keep mosquitoes outside. If needed, sleep under a mosquito bed net.
Prevent Mosquito Breeding

Mosquitoes need water to breed. Young mosquitoes (larvae) live in water before growing into adults that can fly. Items that collect water should be emptied at least once a week to prevent mosquito breeding.

  • Containers: Turn over or cover unused flower pots, buckets, garbage cans, and wheelbarrows. Change water in birdbaths once a week.
  • Gutters: Remove leaves and other debris that can clog gutters and trap water.
  • Pools: Cover unused swimming pools and turn over kiddie pools when not in use. Be sure to keep swimming pool covers clear of leaves and water. Keep large pools treated and circulating.
  • Old Tires: Cover or dispose of them. They are a favorite mosquito-breeding site.​
Boston Public Health Commission
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