Sickle Cell Anemia
Anemia is a condition characterized by reduced red blood cells or subnormal levels hemoglobin, an iron-rich protein that carries oxygen. Anemia results in inadequate oxygen supplies to the body and creates a host of disabling symptoms: weakness, cold, dizziness, shortness of breath, fatigue, cardiac problems, poor concentration and cognitive function, irritability, poor pregnancy outcomes, and difficulty accomplishing the tasks of daily life. Deficiencies of micro-nutrients such as iron, folic acid, vitamin B12 and vitamin A are causes of anemia and common to environments afflicted by poverty, endemic disease and poor healthcare .
According to the World Health Organization (WHO), 2 billion people suffer from anemia worldwide and a larger number are iron deficient. WHO estimates that anemia may account for 20% of maternal deaths . Anemia is especially prevalent in impoverished countries, where 42% of children under five years and 53% of children ages 5-14 years suffer its disabling and deadly effects .
Infectious diseases, including HIV underlie high rates of anemia and increased mortality in less developed countries where hundreds of millions are vulnerable to multiple diseases. Tropical anemia is a consequence of a variety of co-infectious and co-endemic neglected tropical diseases (NTDs): hookworm infection (198 million cases), other helminth infections (335 million cases combined), schistosomiasis (166 million), trachoma (33 million), lymphatic filariasis (46 million), and onchocerciasis (18-37 million) . Anemia associated with NTDs is prevalent in many areas of Africa, Asia, Latin America, the Caribbean and Mexico.
Dr. Peter Hotez describes the effects of 20th century parasitic infections (e.g., hook-worm), which were major causes of severe anemia in the American South until the New Deal programs transformed the economy and prevalence of these diseases: "...hookworm helped to foster the concept of the 'sick man of the South' or 'lazy Southerner''" . Hotez sounds a warning about current US parasitic infections: "Preliminary disease burden estimates of the neglected infections of poverty indicate that tens of thousands, or in some cases, hundreds of thousands of poor Americans harbor these chronic infections, which represent some of the greatest health disparities in the United States" .
Hotez and Molyneux (2008) summarize the link between infectious diseases and anemia: "Together, malaria and the seven most common NTDs .cause almost 2 million deaths and are responsible for the loss of almost 100 million disability-adjusted life years (DALYs) annually (almost 20% higher than the disease burden from HIV/AIDS).... Much of this high disease burden operates through the mechanism of anemia" .
1. Tolentino K, Friedman JF (2007) An Update on Anemia in Less Developed Countries. Am J Trop Med Hyg 77 (1), pp. 44-51.
2. WHO. Turning the tide of malnutrition: responding to the challenge of the 21st century. Geneva: WHO, 2000 (WHO/NHD.007)
3. Tolentino K, Friedman JF (2007).
4. Hotez PJ, Molyneux DH (2008) Tropical Anemia: One of Africa's Great Killers and a Rationale for Linking Malaria and Neglected Tropical Disease Control to Achieve a Common Goal. PLoS Negl Trop Dis 2 (7):e270. doi:10.1371/journal.pntd0000270
5. Hotez PJ (2007) Neglected Diseases and Poverty in "The Other America": The Greatest Health Disparity in the United States? PL0S Negl Trop Dis 1(3):e149. doi:10.1371/journal.pntd.0000256
6. Hotez PJ (2008) Neglected Infections of Poverty in the United States of
America. PLoS Negl Trop Dis 2(6): e256. doi:10.1371/journal.pntd.0000256
7. Hotez and Moyneux (2008).
To Read About Anemia & Parasitic Diseases:
Tropical Anemia: One of Africa's Great Killers and a Rationale for Linking Malaria and Neglected Tropical Disease Control to Achieve a Common Goal. Hotez and Molyneux's (2008) article is freely available on the Public Library of Science Neglected Tropical Disease website.
Neglected Infections of Poverty in the United States of America. Hotez's (2008) article describes neglected infections in the United States. It is freely available on the Public Library of Science Neglected Tropical Disease website. .
Neglected Diseases and Poverty in "The Other America": The Greatest Health Disparity in the United States?Hotez's (2007) article on toxocariasis, cysticercosis, and toxoplasmosis in the United States is freely available on the Public Library of Science Neglected Tropical Disease website.
Water-related diseases: Anaemia. World Health Organization (2000).