Diseases Spread by Mosquitoes: Information for Travelers

Information on mosquito-borne diseases that are not locally acquired in Massachusetts, but are associated with travel to areas of the world experiencing ongoing transmission

Travelers to these areas should avoid mosquito bites and providers seeing patients with recent travel should consider the possibility of infection with these diseases.

What are the common diseases spread by mosquitoes you can get while traveling?

Malaria, yellow fever and dengue fever are the common serious diseases people get from mosquitoes while traveling to tropical countries.  Tropical countries tend to be warm year-round, and are located above and below the equator, in the “tropics.”  Examples of tropical regions are Central America and most of South America, much of Africa, most of India, Southeast Asia and Indonesia.

Malaria is caused by a microscopic parasite that infects your blood.  Yellow fever and dengue fever are both caused by viruses (germs).  These diseases are not found in Europe, Canada, or the United States.

How do people get malaria, yellow fever and dengue fever?

People usually get malaria, yellow fever and dengue fever from the bite of an infected mosquito.  People do not get these diseases by having direct contact with other infected people, birds or animals. 

What are the symptoms of these diseases?

People who are sick with malaria will have fever, chills, headache, muscle aches, and fatigue; usually these symptoms occur in cycles.

Many people who are infected with yellow fever and dengue fever will have no symptoms.  Others will have fever, chills, headache, backache, nausea and vomiting.  Some people will have rash, joint pain, eye pain and internal bleeding, a form of illness called viral hemorrhagic fever.  “Hemorrhagic” means bleeding.  Dengue and yellow fever viruses are two of several viruses that can cause viral hemorrhagic fever.

Is there any treatment for these diseases?

Malaria is treated with medicines (pills) that fight the malaria parasite.

There are no medicines to treat yellow fever or dengue fever.  Most people who get these diseases will get better on their own.

Are there any vaccines or medications to prevent these diseases?

There are medicines (pills) available to help prevent malaria infection while traveling in areas where malaria exists.  It must be taken before travel, during travel, and for a short time after travel.  The medicine must be prescribed by a doctor.

There is no vaccine (shot) or medicine available to protect travelers from dengue fever.  The best way to protect yourself is to not get bitten by mosquitoes.

There is a safe and effective vaccine available to prevent yellow fever infections.  Anyone over 9 months old who is traveling to, or living in, an area with risk of yellow fever should get a yellow fever shot.

Where do these diseases occur?


Malaria is found in parts of Central and South America, Africa, South and Southeast Asia and the Pacific.  A higher risk of malaria is in Africa (south of the Sahara) and in parts of Oceania, such as Papua New Guinea.

Dengue Fever

Dengue is found in at least 100 countries in Asia, the Pacific, the Americas, Africa and the Caribbean.  Dengue infections are often found in the urban areas of tropical nations.

Yellow Fever

Yellow fever occurs in sub-Saharan Africa and parts of tropical South America.

What can you do to protect yourself from these diseases while traveling?

Don’t travel to areas with known outbreaks of viral hemorrhagic fevers.  Check travel advisories issued by the CDC (website below).

Always check with your doctor or a travel clinic before you travel to find out if you will be in an area with high-risk of exposure to a mosquito-borne disease.
When traveling outside the United States you can take the following measures to prevent being infected with these and other mosquito-borne diseases:

  • Get a yellow fever shot, if indicated
  • Take malaria prevention medicine, if needed
  • Use appropriate insect repellant
  • Wear proper clothing to cover your skin
  • Use bed nets to protect yourself from mosquito bites while sleeping
  • Follow any travel advisories.

For more information regarding international travel and viral hemorrhagic fevers, contact the Centers for Disease Control and Prevention (CDC) at (800) 232-4636 or at the CDC Traveler's Health website.

What if I have symptoms of a mosquito-borne disease?

If you have recently traveled to a region where mosquito-borne diseases are common and have any of the symptoms listed above, you should call your healthcare provider immediately and explain your travel history and symptoms.

Can viral hemorrhagic fever viruses be used for bioterrorism?

Yes.  Bioterrorism is the use of any biological organism to intentionally hurt people or create fear.  The Centers for Disease Control and Prevention lists some viral hemorrhagic fever viruses, but neither dengue nor yellow fever, as possible bioterrorist agents.

Where can I get more information?

Spanish and Portuguese translations of this fact sheet are available under additional resources.

Additional Resources

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