Neglected diseases are conditions that inflict severe health burdens on the world's poorest people. Many of these conditions are infectious diseases that are most prevalent in tropical climates, particularly in areas with unsafe drinking water, poor sanitation, substandard housing and little or no access to health care.
Diseases are said to be neglected if they are often overlooked by drug developers or by others instrumental in drug access, such as government officials, public health programs and the news media. Typically, private pharmaceutical companies cannot recover the cost of developing and producing treatments for these diseases.
Another reason neglected diseases are not considered high priorities for prevention or treatment is because they usually do not affect people who live in the United States and other developed nations.
Neglected diseases also lack visibility because they usually do not cause dramatic outbreaks that kill large numbers of people. Rather, such diseases usually exact their toll over a longer period of time, leading to crippling deformities, severe disabilities and/or relatively slow deaths.
The World Health Organization (WHO) estimates that more than 1 billion people — one-sixth of the world's population — suffer from one or more neglected diseases.
The diseases are most heavily concentrated in low-income nations in Africa and Latin America. In addition, neglected diseases take a heavy toll in parts of Asia and the Middle East, although the range of diseases is narrower. Some of these diseases also are occasionally found in areas of the United States with high rates of poverty.
The most common type of neglected diseases are tropical diseases. Many neglected tropical diseases are caused by parasites, which are spread by insects or contact with contaminated water or soil. Examples of these parasitic diseases include:
Specific prevention strategies vary from disease to disease. But experts agree that a good way to head off many neglected diseases is to provide people with safe sources of drinking water, good sanitation, adequate housing and access to health care.
For diseases that are spread by insects, simple measures such as pesticides or hanging nets around beds may help to prevent or reduce the risk of getting infected. For diseases transmitted by snails and other organisms that live in streams and rice paddies, people can reduce their risk by not bathing or wading in water at high risk of contamination. For some diseases caused by bacteria, an effective precaution may be to boil water used for drinking, cooking and hand washing.
Other measures involve giving people medications that will prevent infection or greatly minimize the impact of infection if it does occur. Common examples are the anti-malarial drugs that many take to ward off malaria infections. Still, even at a cost of less than 50 cents a day, such drugs remain too expensive for many poor people.
In addition to drugs, researchers are working to develop vaccines that would spur the body's own immune system to ward off disease-causing agents. But major roadblocks remain. In addition to significant scientific challenges, many drug companies have expressed concerns about how people living in the world's poorest areas would be able to pay for vaccines.
Many people with neglected diseases do not receive proper treatment. One reason is that, due to lack of health care services, they will not be diagnosed with a disease until it is in an advanced stage that is difficult to treat. Even if people are diagnosed early, many cannot afford drugs known to be effective against the disease. Finally, no good treatments exist for some neglected diseases.
Much needs to be done to address all of these challenges. Public health experts are trying to develop better ways of delivering health messages and services to low-income people. They are also educating officials in developing nations about why it makes good economic sense to provide health care and treatments to people suffering from neglected diseases.
For their part, medical researchers are searching for less costly drugs for neglected diseases, and working to develop new drugs for diseases that lack treatments. In recent years, public and non-profit groups have partnered with drug firms in efforts to produce less costly and more effective treatments. Some progress has been made, but the number of drugs developed specifically for neglected diseases still trails behind drugs for other disorders.
Recently, the National Institutes of Health (NIH) launched a new effort, called the Therapeutics for Rare and Neglected Diseases (TRND), program, to create an integrated research pipeline to jump start the development of new treatments for rare and neglected disorders. The NIH Office of Rare Diseases Research (ORDR) handles oversight and governance of TRND. The laboratory work for TRND will be performed in a facility administered by the intramural program of the National Human Genome Research Institute (NHGRI).
To learn more about TRND, go to http://www.ncats.nih.gov/research/rare-diseases/trnd/trnd.html.
As part of its mission, the National Institutes of Allergy and Infectious Diseases (NIAID) of the NIH helps to advance research focused on neglected diseases. To access NIAID's information on neglected tropical diseases, go to www.niaid.nih.gov/topics/tropicaldiseases/Pages/Default.aspx. For information on malaria, go to www.niaid.nih.gov/topics/malaria/Pages/default.aspx.
The Centers for Disease Control and Prevention, which is part of HHS, provides information about some neglected diseases, particularly those that threaten Americans or Americans traveling abroad. A list of diseases related to travel is available at http://wwwnc.cdc.gov/travel/page/diseases.htm.
Another good source of information is the World Health Organization. It offers overviews of various neglected diseases and efforts to combat them at its Web site, www.who.int/en/
Last Updated: May 14, 2012