Traveler Alerts

The Centers for Disease Control and World Health Organization recommend that travelers pay close attention to their health after returning from a trip. Anyone traveling in areas that have Health Alerts should be seen by a health care provider if they are not well after traveling. Symptoms may occur immediately or in several weeks.


Travelers should seek medical care if they have:

  • A fever higher than 101.5F, AND
  • Additional symptoms such as severe headache, muscle pain, vomiting, diarrhea, abdominal pain, or unexplained hemorrhage; AND
  • Epidemiologic risk factors within the previous three weeks before symptom onset, such as contact with blood or other body fluids of a patient known to have or suspected to have Ebola (EVD); residence in, or travel to, an area where EVD transmission is active; or direct handling of bats, rodents, or primates from disease endemic areas.

CDC Ebola virus website.


Middle East respiratory syndrome (MERS) is a viral respiratory illness first reported in Saudi Arabia in 2012. It is caused by a coronavirus called MERS-CoV. Most people who have been confirmed to have MERS-CoV infection developed severe acute respiratory illness. They had fever, cough, and shortness of breath. About 30% of people confirmed to have MERS-CoV infection have died.

Countries in or near the Arabian Peninsula with confirmed MERS - Saudi Arabia, Jordan, Lebanon, Qatar, Kuwait, UAE, Oman, and Yemen

So far, all the cases have been linked to countries in and near the Arabian Peninsula. This virus has spread from ill people to others through close contact, such as caring for, or living with, an infected person. There is no evidence of sustained spreading in community settings.

The CDC continues to closely monitor the MERS situation globally and work with partners to better understand the risks of this virus, including the source, how it spreads, and how infections might be prevented. The CDC recognizes the potential for MERS-CoV to spread farther and cause more cases globally and in the U.S. We have provided information for travelers and are working with health departments, hospitals, and other partners to prepare for this.

Dengue FAQ

What is dengue?

Dengue (pronounced den' gee) is a disease caused by any one of four closely related dengue viruses — DENV 1, DENV 2, DENV 3, or DENV 4. The viruses are transmitted to humans by the bite of an infected mosquito.

In the Western Hemisphere, the aedes aegypti mosquito is the most important transmitter or vector of dengue viruses, although a 2001 outbreak in Hawaii was transmitted by Aedes albopictus. It is estimated that there are over 100 million cases of dengue worldwide each year.

How are dengue and dengue hemorrhagic fever (DHF) spread?

Dengue is transmitted to people by the bite of an aedes mosquito that is infected with a dengue virus. The mosquito becomes infected with dengue virus when it bites a person who has dengue virus in their blood. The person can either have symptoms of dengue fever or DHF, or they may have no symptoms. After about one week, the mosquito can then transmit the virus while biting a healthy person. Dengue cannot be spread directly from person to person.

What are the symptoms of the disease?

The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising). Generally, younger children and those with their first dengue infection have a milder illness than older children and adults.

Dengue hemorrhagic fever is characterized by a fever that lasts from two to seven days, with general signs and symptoms consistent with dengue fever. When the fever declines, symptoms including persistent vomiting, severe abdominal pain, and difficulty breathing, may develop. This marks the beginning of a 24- to 48-hour period when the smallest blood vessels (capillaries) become excessively permeable (“leaky”), allowing the fluid component to escape from the blood vessels into the peritoneum (causing ascites) and pleural cavity (leading to pleural effusions). This may lead to failure of the circulatory system and shock, followed by death, if circulatory failure is not corrected. In addition, the patient with DHF has a low platelet count and hemorrhagic manifestations, tendency to bruise easily or other types of skin hemorrhages, bleeding nose or gums, and possibly internal bleeding.

What is the treatment for dengue?

There is no specific medication for treatment of a dengue infection. Persons who think they have dengue should use analgesics (pain relievers) with acetaminophen and avoid those containing aspirin. They should also rest, drink plenty of fluids, and consult a physician. If they feel worse (e.g., develop vomiting and severe abdominal pain) in the first 24 hours after the fever declines, they should go immediately to the hospital for evaluation.

Chikungunya virus

Chikungunya is an infection caused by the chikungunya virus (CHIKV).


  • Symptoms usually begin three to seven days after being bitten by an infected mosquito.
  • The most common symptoms are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash.
  • Chikungunya disease does not often result in death, but the symptoms can be severe and disabling.

Most patients feel better within a week. In some people, the joint pain may persist for months. People at risk for more severe disease include newborns infected around the time of birth, adults over age 65, and people with medical conditions such as high blood pressure, diabetes, or heart disease. Once a person has been infected, he or she is likely to be protected from future infections.


The symptoms of chikungunya are similar to those of dengue. See your doctor if you develop the symptoms described above. If you have recently traveled, tell your doctor. Your doctor may order blood tests to look for chikungunya or other similar diseases.


There is no medicine to treat chikungunya virus infection or disease. To decrease the symptoms:

  • Get plenty of rest.
  • Drink fluids to prevent dehydration.
  • Take medicines, such as ibuprofen, naproxen, acetaminophen, or paracetamol, to relieve fever and pain.


Polio is a disease caused by a virus that affects the nervous system, and is mainly spread by person-to-person contact. Polio can also be spread by drinking water or other drinks or eating raw or under-cooked food contaminated with the feces of an infected person.

Most people with polio do not feel sick. Some people have only minor symptoms, such as fever, tiredness, nausea, headache, nasal congestion, sore throat, cough, stiffness in the neck and back, and pain in the arms and legs. Most people recover completely. In rare cases, polio infection causes permanent loss of muscle function in the arms or legs (usually the legs) or if there is loss of function of the muscles used for breathing or infection of the brain, death can occur.

Preventing polio

Get the polio vaccine:

  • Find out if you are up to date with your polio vaccination and whether you need a booster dose before traveling. Even if vaccinated as a child or have had polio before, you may need a booster to make sure that you’re protected. See individual destination pages for vaccine recommendation information.
  • Make sure children are vaccinated.
  • See the CDC’s Vaccine Information Statements for more information.

Eat safe foods and drink safe beverages

Follow the CDC’s Food and Water Safety tips to avoid exposure to any food and drinks that could be contaminated with the feces of a person infected with polio.

Practice hygiene and cleanliness

  • Wash your hands often.
  • If soap and water aren’t available, clean hands with hand sanitizer (containing at least 60% alcohol).
  • Don’t touch your eyes, nose, or mouth. If you need to touch your face, make sure your hands are clean.
  • Cover your mouth and nose with a tissue or your sleeve (not your hands) when coughing or sneezing.
  • Try to avoid close contact, such as kissing, hugging, or sharing eating utensils or cups with people who are sick.

CDC travel health alerts

See the latest travelers’ health alerts from the Centers for Disease Control.


The information posted on this website is not intended to replace consultation with a qualified medical professional. Consult a qualified health care provider for medical advice and answers to your personal health questions.