Frequently Asked Questions

Zika is a viral infection that is spread by the bite of an infected mosquito. Outbreaks typically occur in tropical Africa and Southeast Asia. In May 2015, Brazil reported the first outbreak of Zika in the Americas. Zika is now present in tropical areas.

Since this is an evolving situation, the list of affected countries is likely to change. For up‐to-date lists of countries please visit the CDC website or the Pan American Health Organization website. As of February 2, 2016, the countries and territories that have reported ongoing transmission of Zika include American Samoa, Barbados, Bolivia, Brazil, Cape Verde (Africa), Colombia, Costa Rica, Curacao, Dominican Republic, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Nicaragua, Panama, Paraguay, Puerto Rico, Saint Martin, Samoa (Oceania/Pacific Islands), Suriname, U.S. Virgin Islands, and Venezuela.

Locally transmitted cases of Zika by mosquitoes have not been identified in the United States, although the potential for local transmission exists, as Aedes mosquitoes (the mosquitoes that transmit Zika) are present in many states. In late December 2015, the New Jersey Department of Health (NJDOH) identified New Jersey's first laboratory‐confirmed case of Zika in a Bergen county woman exposed in Colombia. While there is no local public health risk associated with this travel‐related case of Zika, the NJDOH informed local health departments (LHDs) and healthcare providers to increase awareness of the risk of Zika in travelers to South and Central America and the Caribbean.

Zika virus can be spread from a pregnant woman to her unborn baby. There have been reports of a serious birth defect of the brain called microcephaly and other poor pregnancy outcomes in babies of mothers who were infected with the Zika virus while pregnant. Knowledge of the link between Zika and these outcomes is evolving, but until more is known, CDC recommends special precautions for the following groups:

• Women who are pregnant (in any trimester):
  • Consider postponing travel to any area where Zika virus transmission is ongoing.
  • If you must travel to one of these areas, talk to your doctor first and strictly follow the steps to prevent mosquito bites during your trip.
• Women who are trying to become pregnant:
  • Before you travel, talk to your doctor about your plans to become pregnant and the risk of Zika virus infection.
  • Strictly follow the steps to prevent mosquito bites during your trip.

Specific areas where Zika virus transmission is ongoing are often difficult to determine and are likely to change over time. As more information becomes available, travel notices will be updated.

While areas in the south and southcentral U.S. are home to the type of mosquito that transmits the Zika virus, a widespread outbreak is not expected. If U.S. mosquitoes become infected with the virus, it will likely result in localized outbreaks which can be controlled through good surveillance and mosquito control efforts. Additionally, in the U.S. there is widespread use of window screens and air conditioning which reduce exposure to mosquitoes. The CDC's assumption is based on studies of other mosquito‐borne diseases, such as dengue and Chikungunya, that had localized transmission in the U.S. but did not expand to large, uncontrollable outbreaks.