Neglected Tropical Diseases (NTDs)
- Lymphatic Filariasis
Lymphatic filariasis (LF), commonly known as elephantiasis is a mosquito-borne parasitic disease caused by thread-like worms of the genus Wuchereria and Brugia. Long-term infection progressively results in profound disfigurement and pain in the limbs and genitals as the parasites lodge in the lymphatic system causing severe swelling, secondary bacterial infections, and fever.
Though the disease is usually irreversible, there is now evidence that treatment can alleviate symptoms of patients suffering from the disease. However, the primary goal of the Global Alliance to Eliminate LF as a public health problem is to stop the spread of infection by reducing worm larvae in the blood of infected persons so that mosquitoes cannot transmit the worms from one human to another. The donation of Mectizan and albendazole is part of the strategy as the combination kills off the microfilariae. WHO recommends a single, annual dose over five years of Mectizan and albendazole in onchocerciasis-endemic countries in Africa and in Yemen, or Mectizan and diethylcarbamazine in all other LF-endemic countries to interrupt transmission.
- Onchocerciasis (river blindness)
Onchocerciasis, also known as river blindness, is a parasitic disease caused by the parasite onchocerca volvulus, transmitted by multiple bites of a black fly that breeds near fast flowing rivers. As the parasite multiplies in the body, its offspring, called microfilariae, invade the skin and cause intense rashes and debilitating itching. When microfilariae enter the eyes, they cause an inflammatory response; long-term this leads to visual impairment and, ultimately, blindness.
Communities affected by river blindness are known to abandon rich farmland to escape the disease. The symptoms of the disease interfere with the ability of adults to work and raise their families and the ability of children to grow and learn.
A single, annual dose of Mectizan given to eligible patients controls the disease and relieves the symptoms. After two decades of free Mectizan, some countries in Latin America have achieved elimination of transmission of the disease and are now stopping treatment. It is now hoped that elimination is also feasible in Africa.
- Schistosomiasis (snail fever)
Schistosomiasis is a parasitic disease caused by trematode flatworms. Larval forms of these parasites are released by freshwater snails, which then penetrate human skin of people bathing or swimming. The larvae live in the blood vessels and when female larvae mature, they release eggs, some of which are passed out of the body, while others are trapped in body tissues causing damage. There are two forms of schistosomiasis. Urinary schistosomiasis results in progressive damage to the bladder, ureters and kidneys. Intestinal schistosomiasis results in progressive enlargement of the liver and spleen, intestinal damage, and hypertension of the abdominal blood vessels. The disease is treated with a single dose of praziquantel; the disease can be controlled with repeated community distribution.
- Soil Transmitted Helminths (intestinal worms)
Soil-transmitted helminths, commonly known as intestinal worms, are highly common in resource-poor communities. The parasitic roundworms that cause soil-transmitted helminthiasis (STH) release eggs into the environment through their faeces. The eggs are either ingested or, in the case of hookworm, larvae penetrate the skin as children walk barefoot in soil contaminated with fecal matter. Infection produces a wide range of symptoms including intestinal manifestations (diarrhea, abdominal pain), malnutrition, anaemia,and weakness. Children infected with 
STH suffer from impaired physical and cognitive development. STH can be treated with mebendazole or albendazole.
- Trachoma
Trachoma is the world’s leading cause of preventable blindness. It is also one of the oldest infectious diseases known to mankind. Trachoma is caused by the infection from the bacterium Chlamydia trachomatis, which is transmitted through contact with eye discharge from an infected person or through transmission by eye-seeking flies. Repeated infections result in scarring of the inside of the eyelid causing it to turn inward such that the eyelashes scratch the cornea causing scarring and ultimately corneal opacity and blindness.
Trachoma is controlled through the WHO-recommended SAFE strategy: Surgery halts the damage caused by inverted eyelashes; Antibiotics (Zithromax) treats infection and prevents transmission; Face washing improves hygiene to reduce the spread of infection; and Environmental change improves sanitation and access to clean water. WHO, the International Trachoma Initiative, and other trachoma partners aim to eliminate the disease by the year 2020 and put an end to blinding trachoma.