Health concerns for traveling to Ecuador and more specifically to the Amazon area: 
The U.S. Department of State and the Centers for Disease Control recommend that travelers receive the following vaccines prior to travel to tropical South America: 

See your doctor at least 4 to 6 weeks before your trip to allow time for immunizations to take effect.  
Hepatitis A or immune globulin (IG)
Hepatitis B, if you might be exposed to blood (for example, health care workers), have sexual contact with the local population, stay more than 6 months in the region, or be exposed through medical treatment.  
Rabies, if you might be exposed to wild or domestic animals through your work or recreation
Typhoid, particularly if you are visiting developing countries in this region.
Yellow fever vaccination, if you will be traveling outside urban areas.
As needed, booster doses for tetanus-diptheria and measles.
Hepatitis B vaccine is now recommended for all infants and for children ages 11-12 years who did not complete the series as infants

Malaria is not currently active in the area of the upper Napo where the group will be staying. The Program Director, Professor Tod Swanson, resides with his family in this community during the summer months and has never taken malaria medications or experienced problems. Students can make their own decisions in regard to proceeding with malarial treatments and immunizations.

For more information about medical travel safety tips, please consult the following web pages: 

Health Information for Travelers to Tropical South America
http://www.cdc.gov/travel/tropsam.htm - which includes information on "To Stay Healthy, Do...", "To Avoid Getting Sick", and "What You Need to Bring with You" as well as lots of links about the specific diseases and their preventative vaccines

Food and Water Precautions and Travelers' Diarrhea
http://www.cdc.gov/travel/foodwater.htm

Tropical South America: Malaria Risk and Prevention
http://www.cdc.gov/travel/regionalmalaria/tropsam.htm - which includes information on anti malarial medication types and how to prevent insect bites

Students please consult your home university's or college's student health clinic; they will usually have a travel clinic that will provide these vaccinations for free or a low price if you have student health insurance. (There is such a clinic at ASU's Student Health and they can be reached at 480-965-3349.) If you are insured through your parents' insurance or your own (other than student health), please consult with your HMO/primary care physician in this regard.

Safety: What can you do to prepare for a safe trip. 
Here is a link to the U.S. State Department which will provide you travel safety tips in order to prepare for your trip to Ecuador this summer.  This resource contains lots of good information about how to travel safely and proactively in order to prevent potential problems. Please read through it before you leave for Ecuador

Travel Safety Information for Ecuador from the U.S. State Department
http://www.state.gov/r/pa/ei/bgn/35761.htm

Health and Safety