Neglected Tropical Diseases (NTDs)


Neglected Tropical Diseases disproportionately affect children, women and persons with disability, and flourish under conditions characterised by poor housing and sanitation, unsafe water, and limited access to basic health care.

A seven year old boy taking Mectizan to prevent onchocerciasis (river blindness)
Photo: CBM

NTDs present a largely hidden burden affecting the most marginalised and voiceless communities living in poverty and conflict zones. Negatively impacting on virtually all Millennium Development Goals (MDGs), NTDs hinder development, keeping individuals and communities trapped in a cycle of poverty.

Neglected Tropical Diseases are primarily parasitic and bacterial infections that thrive in impoverished settings, especially in the heat and humidity of tropical climates. They are spread by insects, contaminated water and soil infested with the eggs or larvae of worms.

Transmission cycles are perpetuated under conditions of environmental contamination, protracted by poor standards of living and hygiene. Once widely dispersed, NTDs now persist in settings of extreme poverty, urban slums and conflict zones. Though diverse in terms of causes and effects, NTDs frequently affect the same communities causing pain and chronic disability, impairing childhood growth and mental development, and hindering economic growth.

  • More than 1 billion people - 1/6 of the world's population - are affected by one or more NTDs. Another 2 billion people are at risk, mainly in the tropics and sub-tropics.
  • Anchoring individuals and communities in a cycle of poverty, NTDs cause great human misery, often aggravated by social stigmatisation and discrimination, especially for women.
  • NTDs cause pain, disfigurement, and disability (mental and physical), and result in about half a million deaths each year.
  • Disease development is insidious and severe impairment often occurs after years of silent infection, leaving patients unaware of the need to seek care.

The following diseases are responsible for about 90% of the global NTD burden:

  • Lymphatic filariasis (elephantiasis) - affecting 120 million people - is caused by parasitic worms transmitted by mosquitoes, and can lead to the swelling of limbs also known as "elephantiasis".
  • Onchocerciasis (river blindness) - Affecting 37 million people - is a parasitic disease caused by a roundworm and is the world's second leading infectious cause of blindness.
  • Soil-transmitted helminths (3 types) - affecting approximately 2 billion people - are parasites found in the soil that can cause a wide range of problems such as diarrhoea, abdominal pain, anaemia and general weakness; severe infection can impair growth and cognitive development.
  • Trachoma - affecting an estimated 84 million people - is an infectious eye disease, and the leading cause of global infectious blindness.
  • Schistosomiasis (snail fever, also known as bilharzia) - affecting around 261 million people - is caused by a parasitic worm; it can damage internal organs and, in children, impair growth and cognitive development.

The five major NTDs above are also called 'tool ready' as simple diagnostic tools exist for them, and safe inexpensive or free drugs are available, which can be distributed by trained non-medical staff.

Hand and face washing is important in avoiding trachoma.A fieldworker teaching pupils of a primary school in Kenya's Eastern Province, in the village of Mutuati, how hand and face washing is important in avoiding trachoma. Photo: CBM/Tobias Pflanz

CBM has been successfully involved in prevention of blindness from onchocerciasis and trachoma for more than 20 years.

  • Onchocerciasis (river blindness) - CBM supports annual treatment through community directed approach. CBM is mainly active with partners in Central African Republic, Nigeria, DRC, Southern Sudan and Burundi. As a founding member of the NGDO Group for Onchocerciasis Control, CBM was involved in the founding of the African Program for Onchocerciasis Control (APOC).
  • Trachoma - CBM supports a comprehensive SAFE strategy (acronym for Surgery for trichiasis, Antibiotic therapy, Facial cleanliness, and Environmental improvement) with expertise mainly in trichiasis-surgery. CBM is mainly active with partners in Ethiopia, Myanmar, Pakistan, India, Tanzania, Vietnam, Afghanistan, Kenya, China, Cameroon, and Nigeria. The number of people affected by blinding Trachoma has fallen from 360 million people in 1985 to approximately 84 million today. CBM is a member of the International Coalition for Trachoma Control (ICTC).
  • NTD programme - In 2007 CBM UK, in collaboration with Ministry of Health and other partners stated a comprehensive NTD control programme in Burundi with financial support from Geneva Global.

The primary focus in current NTD programmes is on prevention and treatment. However, it is important to recognise the need for continuum of care for people affected, in order to reduce suffering from morbidity, stigma and poverty, and enable participation in family and community life.

CBM's partners strong experience in community base rehabilitation (CBR) self-help groups and livelihood results in the availability of unique technical expertise in this often-neglected area.

Women taking part in the schistosomiasis survey in Burundi, part of a Neglected Tropical Diseases programme. Photo : CBMWomen taking part in the schistosomiasis survey in Burundi, part of a Neglected Tropical Diseases programme. Photo : CBM

Further Reading

APOC - Visit the African Program for Onchocerciasis Control (APOC) website

ICTC -Visit the International Coalition for Trachoma Control (ICTC) website

Visit the Neglected Tropical Disease NDGO Network website

Read our article in the Guardian April 2013 by Prof. KH Martin Kollmann, CBM Senior Advisor for Neglected Tropical Diseases.