My husband and three-year-old daughter are going to Ecuador for two months. What immunizations should we get?

Linda

This is a very difficult question to answer in a detailed manner in a small amount of space. I will give the specific recommendations for U.S. citizens traveling to Ecuador and explain some of the concepts that apply to North Americans traveling to many different areas. See my column on travel to Africafor more information. See also the U.S. Centers for Disease Control (CDC) traveler's health website for information about travel to any part of the world.

Travel to less-developed parts of the world can result in a variety of infections. By far the most common is gastroenteritis, or "traveler's diarrhea." Sterilizing all foods you eat can prevent this disease. This usually means boiling water and avoiding any uncooked foods that have come in contact with potentially contaminated water. Your doctor may prescribe an antibiotic to take as soon as you have the first episode of diarrhea.

Malaria is a common infection in many, if not most, parts of the world. This parasitic infection is spread by mosquitoes, and it can be fatal. A very important step to take is insect avoidance -- using mosquito netting and repellents. These precautions will also help prevent infections such as dengue, for which there is no other mode of prevention. The CDC recommends preventive therapy with mefloquine (Lariam) if traveling in various parts of Ecuador. Check the CDC malaria website for information about the risk in specific regions in Ecuador.

Yellow fever is a potentially fatal infection of the liver caused by a virus spread by mosquitoes. It occurs in parts of South America and Africa. There is a very effective vaccine for yellow fever, and this vaccine is the only immunization required by law in some countries. You must check with the Ecuadorian consulate to be sure of the current law and how it applies to you. Ecuador currently requires the yellow fever vaccine if you will be traveling to Ecuador after visiting an area that has yellow fever. The CDC also recommends having the yellow fever vaccine if traveling in certain areas in Ecuador. There are some contraindications to this vaccine (as with all vaccines) that must be ruled out by a health-care professional.

You should also get the typhoid vaccine, particularly if you will be traveling to undeveloped areas. The CDC also recommends the hepatitis A vaccine if you will be leaving in more than two weeks. If the trip starts sooner, you should get hepatitis A immune globulin (disease-fighting antibody). The hepatitis B vaccine is needed if you will be at risk of exposure to this virus -- typically through blood or sexual contact.

Rabies is still relatively common in some parts of the world. Never approach any stray animal in Ecuador or any South American country. If you think there is a good chance that you will be exposed to animals while traveling, discuss rabies treatment and prevention with your health-care provider.

Finally, your husband and daughter should get all the recommended boosters to prevent tetanus, diphtheria and measles. Your daughter should already be up to date, but depending on your age and your husband's, you may need some boosters.

I hope that I have not scared you too much. If there is one thing I want to impress on you, though, it is make sure your drinking water is safe. This alone will prevent most of the common infections that occur in travelers.