Image is courtesy of Financial Times.
According to a report from the World Health Organization, only 10% of global health research is dedicated to conditions that affect 90% of the world. This is called the ‘10/90’ gap and attempts to illustrate poverty’s relation to disease. In developing countries, disease is extremely prevalent. Many of the people living there do not have access to treatment or new medical technology. These diseases are given little attention from global pharmaceutical industries since they cannot offer any marketable or profitable qualities. Moreover, they are often overlooked by government officials, public health programs, and the media. Due to this, they have been given the name neglected diseases.
What are neglected diseases?
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It is estimated that 1 billion people in 149 countries suffer from a neglected disease. These diseases are exacerbated by poor living conditions, including lack of clean water and sanitation. As reported in the 2002 World Health Organization’s World Health Report, tropical diseases accounted for only 0.5% of deaths in high-mortality poor countries and 0.3% in low-mortality poor countries. Although these diseases have a low mortality rate, they can cause severe and permanent disabilities. In addition to this, they create a systemic cycle of poverty and can have social impacts.
Image is courtesy of SITNBoston.
Neglected diseases are predominantly found in Africa, Asia, and Latin America. Currently, there are 20 neglected tropical diseases. Some examples include:
Dengue Fever
Dengue is a mosquito-borne disease caused by the virus DENV. It is found in tropical and sub-tropical climates. The virus is transmitted through the bite of a female mosquito, most often the Aedes aegypti mosquito. Symptoms are similar to the flu, and severe cases can lead to bleeding, organ impairment, and death. There are no specific treatments for dengue. Controlling symptoms can be done through pain killers and fever reducers.
Chagas Disease
Also known as American trypanosomiasis, Chagas disease is a parasitic disease caused by the parasite Trypanosoma cruzi. It is transmitted through insects known as “kissing bugs” or Triatominae. This can occur through contaminated food or infected blood. Symptoms include fever, body aches, rash, or diarrhea in the acute phase and cardiac/gastrointestinal complications in the chronic phase.
Cysticercosis
Cysticercosis is a parasitic infection caused by the tapeworm Taenia solium. Larval cysts begin to infect the brain, muscle, and tissues of the body. Cysticercosis is contracted by the ingestion of food contaminated with the eggs of the tapeworm. Most cases are found in Mexico, Latin America, South America, Eastern Europe, and Southeast Asia. Symptoms can be very severe if the central nervous system is involved. This includes seizures, headaches, change of vision, stroke, and coma.
Echinococcosis
Echinococcosis is caused by ingesting parasites in animal feces. Contaminated water, soil, and vegetables are the leading cause of infections. This disease comes in two versions: cystic and alveolar. In cystic echinococcosis, cysts form in the liver and lungs due to the parasite Echinococcus granulosus. This tapeworm is found in dogs, sheep, cattle, goats, and pigs. In alveolar echinococcosis, infection is caused by Echinococcus multilocularis, found in rodents. Alveolar echinococcosis is rare for humans, but if contracted and untreated, it can be fatal. Treatment includes surgery to remove the cysts.
Buruli Ulcer
Buruli ulcer is caused by the bacterium Mycobacterium ulcerans. It affects the skin and bones, and most cases are found in West Africa and Australia. The exact cause of infection is unknown, but it is speculated to be passed through insects found in water. Symptoms of Buruli ulcer include swelling, destroyed skin tissue, and painless ulcers. If left untreated, the disease can cause bone infection, deformity, and even disability. Antibiotics can be used to treat the disease.
Fascioliasis
Fascioliasis is caused by contaminated watercress or other plants. It is due to two species of parasitic flatworms that affect the liver. According to the World Health Organization, at least 2.4 million people are at risk, and most cases occur in Africa and Asia. In acute fascioliasis, liver cells will be killed by immature worms penetrating the intestinal wall. In the chronic phase, worms start to mature and produce eggs. Symptoms at this stage include pain, jaundice, gallstones, and pancreatitis.
African Sleeping Sickness
Better known as African trypanosomiasis, African sleeping sickness is transmitted by the bite of tsetse flies in rural Africa. The disease comes in two forms: East African trypanosomiasis and West African trypanosomiasis. Of the former, only 100 cases have been reported to the World Health Organization since 2015, and of the latter, fewer than 2000 cases have been reported. If untreated, the disease can migrate to the central nervous system, causing seizures, mental disorders, and death.
How can we tackle them?
Currently, there are global neglected tropical disease programs that work to control or eliminate them. Some of these are:
WHO’s SAFE strategy to control Trachoma
For most neglected diseases, treatment exists and the issue lies in obtaining access to them. Governments often place tariffs and taxes on medicines and prioritize funding for the military rather than healthcare.
Some regional success has been achieved with mass drug administration campaigns delivered by WHO; however, more work needs to be done. This includes enhancing water supply and sanitation, delivering veterinary public health and vector-control interventions, and increasing access to vaccines.
Image is courtesy of World Health Organization.
In January 2021, the World Health Organization released a document called Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030. The report shows past measures and new initiatives used to tackle neglected diseases. It calls to “end the epidemics of… neglected tropical diseases” by 2030. The plan includes three pillars: accelerate programmatic action, intensify cross-cutting approaches, and change operating models and culture to facilitate country ownership.
Article Author: Jennifer Law
Article Editors: Victoria Huang, Maria Giroux