The facts on the mosquito-borne disease that has the CDC urging some travelers to reconsider their vacations. 
Mosquito net
Credit: Monica Buck

On January 15, the Centers for Disease Control (CDC) issued an unprecedented travel alert—the first to apply to a particular subset of people—for South American, Central American, and Caribbean countries due to growing concern about the potential dangers of the Zika virus, a disease that’s transmitted to humans via mosquito bites. The warning, which is at a level two (out of three), means travelers should “practice enhanced precautions.” Here, experts answer common questions about the Zika virus:

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Mosquito net
Credit: Monica Buck

1 What is the Zika Virus?

Mosquitos in the "Aedes" genus, which include many species that live in tropical and subtropical climates such as Latin America and the Caribbean, harbor the virus and then infect humans through mosquito bites, says Nicolette A. Louissaint, Ph.D., director of programming for Healthcare Ready in Washington D.C.

2 Where Are Travelers Most at Risk of Contracting It?

The CDC travel warning applies to Central America, South America, the Caribbean, Cape Verde, and the Pacific Islands, as well as Mexico and Puerto Rico.

3 Who is at Risk?

Anyone who travels to these regions (especially the 14 countries and territories identified by the CDC) is at risk for infection, says Louissaint. However, healthcare professionals warn women of childbearing age to be particularly cautious because of a potential link between the Zika virus and microcephaly, a type of birth defect that can cause a fetus to develop an abnormally small head and brain, says Dr. Guajira Thomas, MD, infectious disease specialist at Northwestern Medicine in Chicago.

4 What Are the Symptoms?

For the most part, it’s not considered a serious infection, says Thomas. According to the CDC, only 1 in 5 people infected with the Zika virus become ill—and many don’t experience any symptoms. Those who do feel sick may experience symptoms similar to other infections, says Louissant: Fever, rash, joint pain, and conjunctivitis (red eyes).

5 What is the Treatment Process?

If you contract the Zika virus, you can expect to be sick for up to seven days, says Thomas. Because Zika is an acute infection, she explains, treatment is mostly about the symptoms: Hydrating, taking acetaminophen (aspirin and other anti-inflammatory medications—like ibuprofen and naproxen—should be avoided until you are tested to rule out Dengue fever) to lower fever and reduce pain, and getting plenty of rest are among the recommendations.

6 When Should You See a Doctor?

Though the illness is usually mild, the CDC urges anyone who has traveled to an affected region and developed symptoms to see a doctor immediately. Any person returning from travel abroad who develops fever or a rash should contact their physician not just out of concern for Zika, but also to rule out things that do require special treatment (like Dengue), says Thomas.

7 Is It Contagious?

Transmission typically occurs when a mosquito bites an infected individual and that infected mosquito bites another person, explains Thomas. There has been one report of possible transmission via blood transfusion and another report of possible transmission through sexual contact, causing the CDC to recommend using condoms or abstaining from sex after travel to affected areas.

8 Is There a Vaccine?

There is currently no vaccine to prevent infection.

9 What Kind of Precautions Can You Take to Ensure You Don’t Contract Zika?

“If you are traveling to Central America, South America and/or the Caribbean, plan to use a lot of insect repellent such as DEET,” says Louissant. “Also wear long clothing to cover skin and prevent mosquito bites. Finally, don't sleep outdoors. Sleep in enclosed and screened areas.”

Both men and women should be aware of their sexual partner's travel history and use condoms or abstain from sex if there is any possibility of infection, says Dr. Michael Angarone, D.O., infectious diseases specialist with Northwestern Medicine.

10 Do You Really Have to Cancel a Planned Trip to Susceptible Areas?

Currently the CDC recommends women who are pregnant or planning to become pregnant in the immediate future avoid traveling to affected areas, says Thomas.

11 If You Get a Mosquito Bite Abroad, Should You Worry?

If you get a mosquito bite abroad, use insect repellent to prevent additional bites. Then track your symptoms and call your doctor if any develop, says Louissant. In the absence of symptoms, women who are currently pregnant should still consult their doctor if they get mosquito bites while traveling in affected areas, adds Thomas.

12 Is Zika a Threat In the United States?

“So far, the very few cases in the U.S. have all been acquired abroad,” says Thomas.