Global Immunization: Neglected Tropical Diseases

What are NTDs?

Neglected tropical diseases (NTDs) are a group of infectious diseases that are considered “neglected” because they have traditionally received relatively little attention from global governments and health organizations. More than 1.5 billion people suffer from one or more NTDs. This group includes more than 830 million children in the developing world who are infected with one or more of the most common NTDs:

  • Ascariasis, also known as roundworm, is transmitted by contaminated food or water causing inflammation and/or obstruction of the intestine and malnourishment due to the poor functioning of the intestine.
  • Trichuriasis, also known as whipworm, is spread by contaminated food or water and can cause growth delays, malnutrition and anemia.
  • Hookworm enters the body through exposure of the skin (most often the feet) to larvae in contaminated soil. Its effects are similar to those listed for trichuriasis.
  • Lymphatic filariasis, also known as elephantiasis, is transmitted by mosquitos and causes swollen or enlarged parts of the body, particularly the arms and legs, resulting in disfigurement and permanent disabilities.
  • Onchocerciasis, also known as river blindness, is spread by the bite of infected black flies and causes blindness and skin lesions.
  • Schistosomiasis, also known as snail fever, is carried by fresh water snails and can result in anemia, malnutrition and widespread organ damage.
  • Trachoma is an infectious disease of the eye caused by the bacterium Chlamydia trachomatis; it’s the world’s leading cause of preventable blindness.

Burdening the world’s poorest

NTDs thrive in places with:

  • Unsafe water
  • Poor sanitation
  • Limited access to basic healthcare

Although these diseases are transmitted in different ways and cause different symptoms, people are often infected with more than one at a time. Communities with many members affected by one or more of these diseases have problems associated with:

  • Childhood health
  • Pregnancy outcomes
  • Worker productivity
  • Economic development

As a result, NTDs contribute to a cycle of poverty that traps the world’s poorest individuals and stifles economic growth in developing countries.

Progress and advances

An improved understanding of the relationship between NTDs and extreme poverty has led to increased attention from global and national organizations in recent years. Inexpensive, safe and effective drugs are now available to treat some of the most common NTDs. Current efforts to control or eliminate these diseases include:

  • Treatment programs, such as distribution of medications or deworming programs
  • Environmental improvements
  • Educational campaigns

Vaccines are not currently available to prevent any of the NTDs, but efforts are being made to develop safe and inexpensive vaccines for some of these diseases.

Other resources

  • Sabin Vaccine Institute, founded in honor of Albert Sabin, the developer of the live polio vaccine, aims to reduce suffering caused by vaccine-preventable diseases and neglect. The Sabin Vaccine Institute leads the End7 Campaign.
  • The END Fund works to ensure people at risk of neglected tropical diseases can live healthy and prosperous lives. The organization works to build partnerships, design programs, and strengthen systems capacity to decrease the impact of NTDs in communities in which they are working.

Reviewed by Paul A. Offit, MD on March 19, 2018

Materials in this section are updated as new information and vaccines become available. The Vaccine Education Center staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family's personal health. You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel.