More Facts
- Neglected tropical diseases (NTDs) are widespread in the world’s poorest regions, where water safety, sanitation, and access to health care are substandard.
- An estimated 1 billion people—approximately one-sixth of the world’s population—suffer from at least one NTD.
- NTDs are called “neglected” because they generally are not considered public health problems in wealthier nations and historically have not received as much attention as other diseases.
- Some NTDs are found in parts of the United States, particularly among impoverished minorities.
- NTDs comprise several diseases that have a range of effects, from extreme pain to permanent disability to death. Here are some examples:
- Ascariasis: Caused by the soil-transmitted roundworm Ascaris lumbricoides, it can impair growth and cognition.
- Buruli ulcer: Caused by Mycobacterium ulcerans, it can lead to massive skin ulceration.
- Chagas disease (American trypanosomiasis): Caused by a parasite transmitted by blood-sucking “assassin bugs,” it can lead to swollen lymph nodes and organ damage.
- Dracunculiasis (guinea-worm disease): Contracted by drinking water contaminated with larvae of the parasitic worm Dracunculus medinensis, it causes painful, erupting blisters as the worms emerge through the skin.
- Hookworm: Often contracted by walking barefoot on soil contaminated by feces, hookworm infections can causes blood loss and anemia.
- Human African trypanosomiasis (sleeping sickness): Caused by a parasite transmitted from tsetse flies, it can lead to fever, weakness, stiffness, and death.
- Leishmaniasis: A parasitic disease transmitted by infected sand flies, it can cause skin ulcers or lesions and swelling of the spleen and liver.
- Leprosy (Hansen’s disease): A chronic infectious disease caused by bacteria, it can lead to permanent damage to the skin, nerves, limbs, and eyes.
- Lymphatic filariasis (elephantiasis): A parasitic worm disease spread from human to human by mosquitoes, it can lead to disfiguring swelling of the legs, scrotum, and breast.
- Onchocerciasis (river blindness): A parasitic worm disease spread from by infected black flies, it can cause extreme itching, blindness, and skin lesions.
- Schistosomiasis: A parasitic worm disease transmitted by fresh water snails, it can lead to blood in the urine, impaired growth, and malfunctioning of the kidney, liver, and spleen.
- Trachoma: Caused by the bacterium Chlamydia trachomatis, it can lead to scarring of the inside of the eyelid and blindness.
- Trichuriasis: Contracted by ingesting soil or vegetables contaminated with feces containing whipworm eggs, it can cause dehydration and anemia and impair growth and cognition.
- Despite their pervasiveness around the world, most NTDs are relatively easy to treat and can be prevented.