Diseases of poverty

Diseases of poverty is a term sometimes used to collectively describe diseases and health conditions that are more prevalent among the poor than among wealthier people. In many cases poverty is considered the leading risk factor or determinant for such diseases, and in some cases the diseases themselves are identified as barriers to economic development that would end poverty. These diseases are in contrast to so-called "diseases of affluence", which are diseases thought to be a result of increasing wealth in a society.

Examples

At the global level, the three primary diseases of poverty are AIDS, malaria, and tuberculosis.^[1] Developing countries account for 95% of the global AIDS prevalence^[2] and 98% of active tuberculosis infections.^[3] Furthermore, 90% of malaria deaths occur in sub-Saharan Africa.^[4] Together, these three diseases account for 10% of global mortality.^[1]

Three other diseases, measles, pneumonia, and diarrheal diseases are also closely associated with poverty, and are often included with AIDS, malaria, and tuberculosis in broader definitions and discussions of diseases of poverty.^[5]

In addition, infant mortality and maternal mortality are far more prevalent among the poor. For example, 98% of the 11,600 daily maternal and neonatal deaths occur in developing countries.^[6]

Together, diseases of poverty kill approximately 14 million people annually.^[3] However, partial results released in October 2009 study on diarrheal diseases show they alone kill some 2.6 million people annually, much more than previously thought.^[7][8]

AIDS

AIDS is a disease of the human immune system caused by the human immunodeficiency virus (HIV).^[9] Primary modes of HIV transmission in sub-Saharan Africa are sexual intercourse, mother-to-child transmission (vertical transmission), and through HIV-infected blood.^[10][11][12] Since rate of HIV transmission via heterosexual intercourse is so low, it is insufficient to cause AIDS disparities between countries.^[10] Critics of AIDS policies promoting safe sexual behaviors believe that these policies miss the biological mechanisms and social risk factors that contribute to the high HIV rates in poorer countries. ^[10] In these developing countries, especially those in sub-Saharan Africa, certain health factors predispose the population to HIV infections.^{[13][14][15][16][17]}

Mechanisms and Causes

For many environmental and social reasons, including crowded living and working conditions, inadequate sanitation, and disproportionate occupation as sex workers, the poor are more likely to be exposed to infectious diseases. Malnutrition, stress, overwork, and inadequate, inaccessible, or non-existent health care can hinder recovery and exacerbate the disease.^[18] Malnutrition is associated with 54% of childhood deaths from diseases of poverty, and lack of skilled attendants during childbirth is primarily responsible for the high maternal and infant death rates among the poor.^[6][19]

Lack of Nutrition

Malnutrition disproportionately affect those in sub-Saharan Africa. Over 35 percent of children under the age of 5 in sub-Saharan Africa show physical signs of malnutrition.^[20] Malnutrition, the immune system, and infectious diseases operate in a cyclical manner: infectious diseases have deleterious effects on nutritional status, and nutritional deficiencies can lower the strength of the immune system which affects the body’s ability to resist infections.^[20] Similarly, malnutrition of both macronutrients (such as protein and energy) and micronutrients (such as iron, zinc, and vitamins) increase susceptibility to HIV infections by interfering with the immune system and through other biological mechanisms. Depletion of macronutrients and micronutrients promotes viral replication that contributes to greater risks of HIV transmission from mother-to-child as well as those through sexual transmission.^[21] Increased mother-to-child transmission is related to specific deficiencies in micronutrients such as vitamin A.^[17][22] Further, anemia, a decrease in red the number of red blood cells, increases viral shedding in the birth canal, which also increases risk of mother-to-child transmission.^[23] Without these vital nutrients, the body lacks the defense mechanisms to resist infections.^[20] At the same time, HIV lowers the body’s ability to intake essential nutrients. HIV infection can affect the production of hormones that interfere with the metabolism of carbohydrates, proteins, and fats.^[20]

Inadequate sanitation

Contaminated water and inadequate sanitation are related to diseases of poverty such as malaria, parasitic diseases, and schistosomiasis.^[24] These infections act as cofactors that increase the risk of HIV transmission.^[10]

Africa also accounts for a majority of malaria infections and deaths worldwide. Over 90 percent of the 300 to 500 million malaria infections occurring annually worldwide are in Africa. Each year, about one million malaria deaths happen in children under the age of five.^[25] Malaria is directly related to the spread of HIV in sub-Saharan Africa.^[26] It increases viral load seven to ten times, which increases the chances of transmission of HIV through sexual intercourse from a patient with malaria to an uninfected partner.^[27] After the first pregnancy, HIV can also decrease the immunity to malaria. This contributes to the increase of the vulnerability to HIV and higher mortality from HIV, especially for women and infants.^[28] HIV and malaria interact in a cyclical manner—being infected with malaria increases susceptibility to HIV infection, and HIV infections increase malarial episodes. The co-existence of HIV and malaria infections helps spread both diseases, particularly in Sub-Saharan Africa.^[29]

Intestinal parasites are extremely prevalent in tropical areas.^[10] These include hookworms, roundworms, and other amoebas. They can aggravate malnutrition by depleting essential nutrients through intestinal blood loss and chronic diarrhea. Chronic worm infections can further burden the immune system.^[30][31] At the same time, chronic worm infections can cause immune activation that increases susceptibility of HIV infection and vulnerability to HIV replication once infected.

Schistosomiasis (bilharzia) is a parasitic disease caused by the parasitic flatworm trematodes. Moreover, more than 80 percent of the 200 million people worldwide who have schiostosomiasis live in sub-Saharan Africa.^[32] Infections often occur in contaminated water where freshwater snails release larval forms of the parasite. After penetrating the skin and eventually traveling to the intestines or the urinary tract, the parasite lays eggs and infects those organs.^[10][32] It damages the intestines, bladder, and other organs and can lead to anemia and protein-energy deficiency.^[13][33] Along with malaria, schiostosomiasis is one of the most important parasitic cofactors aiding in HIV transmission. Epidemiological data shows schistosome-endemic areas coincide with areas of high HIV prevalence, suggesting that parasitic infections such as schiostosomiasis increase risk of HIV transmission.^[34]

Consequences

Diseases of poverty reflect the dynamic relationship between poverty and poor health; while such diseases result directly from poverty, they also perpetuate and deepen impoverishment by sapping personal and national health and financial resources. For example, malaria decreases GDP growth by up to 1.3% in some developing nations, and by killing tens of millions in sub-Saharan Africa, AIDS alone threatens “the economies, social structures, and political stability of entire societies”.^[35][36]

For Women

Women and children are often put at a high risk of being infected by schiostosomiasis, which in turn puts them at a higher risk of acquiring HIV.^[10] Since the mode of schiostosomiasis transmission is usually through contaminated water in streams and lakes, women and children who do their household chores by the water are more likely to acquire the disease. Activities that women and children often do around waterfront include washing clothes, collecting water, bathing, and swimming.^[10][32] Women who have schiostosomiasis lesions are three times more likely to be infected with HIV.^[37]

Women also have a higher risk of HIV transmission through the use of medical equipment such as needles.^[10] Because more women than men use health services, especially during pregnancy, they are more likely to come across unsterilized needles for injections.^[11][37] Although statistics estimate that unsterilized needles only account for 5 to 10 percent of primary HIV infections, studies show this mode of HIV transmission may be higher than reported.^[10][38] This increased risk of contracting HIV through non-sexual means has social consequences for women as well. Over half of the husbands of HIV-positive women in Africa tested HIV-negative.^[39] When HIV-positive women reveal their HIV status to their HIV-negative husbands, they are often accused of infidelity and face violence and abandonment from their family and community.^[10][39]

Relating to Human Capabilities

Malnutrition associated with HIV impacts people’s ability to provide for themselves and their dependents, thus limiting the human capabilities of both themselves and their dependents.^[20] HIV can negatively affect work output, which impacts the ability to generate income.^[40] This is crucial in parts of Africa where farming is the primary occupation and obtaining food is dependent on the agricultural outcome. Without adequate food production, malnutrition becomes more prevalent. Children are often collateral damage in the AIDS crisis. As dependents, they can be burdened by the illness and eventual death of one or both parents due to HIV/AIDS. Studies have shown that orphaned children are more likely to display physical symptoms of malnutrition than children whose parents are both alive.^[20]

Proposed Policy Solutions

Changes to HIV/AIDS Policy

• Nutrition Supplements: Focusing on reversing the pattern of malnutrition in sub-Saharan African and other poor countries is a one possible way of decreasing susceptibility to HIV infections. Micronutrients such as iron and vitamin A can be delivered and provided at a very low cost. For example, vitamin A supplements cost $0.02 per capsule if provided twice a year. Iron supplements per child cost $0.02 if provided weekly or $0.02 if provided daily.^[10]
• Eliminating Cofactors: Tackling the very diseases that increase risk of HIV infections can help slow down the rates of HIV transmission. Cofactors such as malaria and parasitic infections can be combated in an effective and cost-efficient manner. For example, mosquito nets can be easily used to prevent malaria.^[10] Parasites can be eliminated with medication that is cost-effective and easy to administer. Twice-yearly treatments range from $0.02 to $0.25 depending on the type of worm.^[41][42]

See also

• Contagious disease
• Neglected diseases
• Orphan diseases
• Tropical disease
• Global health
• Poverty trap

External links

• United Nations Population Fund: State of World Population 2002
• RESULTS: World Health/Diseases of Poverty
• Roll Back Malaria Global Partnership

Further reading

• Agriculture and HIV/AIDS : understanding the links between agriculture and health (brief) by Stuart Gillespie (2006) International Food Policy Research Institute

References

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