Social determinants of health

From Wikipedia, the free encyclopedia

The social determinants of health are the economic and social conditions that influence individual and group differences in health status. They are the health promoting factors found in one's living and working conditions (such as the distribution of income, wealth, influence, and power), rather than individual risk factors (such as behavioral risk factors or genetics) that influence the risk for a disease, or vulnerability to disease or injury. The distributions of social determinants are often shaped by public policies that reflect prevailing political ideologies of the area. The World Health Organization says, "This unequal distribution of health-damaging experiences is not in any sense a 'natural' phenomenon but is the result of a toxic combination of poor social policies, unfair economic arrangements [where the already well-off and healthy become even richer and the poor who are already more likely to be ill become even poorer], and bad politics."

Commonly accepted determinants

Social Determinants of Health Map

 

There is no single definition of the social determinants of health, but there are commonalities, and many governmental and non-governmental organizations recognize that there are social factors which impact the health of individuals. 

In 2003, the World Health Organization (WHO) Europe suggested that the social determinants of health included:

• The social gradient
• Stress
• Early life
• Social exclusion
• Work
• Unemployment
• Social support
• Addiction
• Food
• Transportation

In Canada, these social determinants of health have gained wide usage.

1. Income and income distribution
2. Education
3. Unemployment and job security
4. Employment and working conditions
5. Early childhood development
6. Food insecurity
7. Housing
8. Social exclusion/inclusion
9. Social safety network
10. Health services
11. Aboriginal status
12. Gender
13. Race
14. Disability

These social determinants of health are related to health outcomes, public policy, and are easily understood by the public to impact health. They tend to cluster together – for example, those living in poverty experience a number of negative health determinants.

In 2008, the WHO Commission on Social Determinants of Health published a report entitled "Closing the Gap in a Generation." This report identified two broad areas of social determinants of health that needed to be addressed. The first area was daily living conditions, which included healthy physical environments, fair employment and decent work, social protection across the lifespan, and access to health care. The second major area was distribution of power, money, and resources, including equity in health programs, public financing of action on the social determinants, economic inequalities, resource depletion, healthy working conditions, gender equity, political empowerment, constitution of reserves and a balance of power and prosperity of nations.

The 2011 World Conference on Social Determinants of Health brought together delegations from 125 member states and resulted in the Rio Political Declaration on Social Determinants of Health. This declaration involved an affirmation that health inequities are unacceptable, and noted that these inequities arise from the societal conditions in which people are born, grow, live, work, and age, including early childhood development, education, economic status, employment and decent work, housing environment, and effective prevention and treatment of health problems.

The United States Centers for Disease Control defines social determinants of health as "life-enhancing resources, such as food supply, housing, economic and social relationships, transportation, education, and health care, whose distribution across populations effectively determines length and quality of life". These include access to care and resources such as food, insurance coverage, income, housing, and transportation. Social determinants of health influence health-promoting behaviors, and health equity among the population is not possible without equitable distribution of social determinants among groups.

Steven H. Woolf, MD of the Virginia Commonwealth University Center on Human Needs states, "The degree to which social conditions affect health is illustrated by the association between education and mortality rates". Reports in 2005 revealed the mortality rate was 206.3 per 100,000 for adults aged 25 to 64 years with little education beyond high school, but was twice as great (477.6 per 100,000) for those with only a high school education and 3 times as great (650.4 per 100,000) for those less educated. Based on the data collected, the social conditions such as education, income, and race were dependent on one another, but these social conditions also apply to independent health influences.

Marmot and Bell of the University College London found that in wealthy countries, income and mortality are correlated as a marker of relative position within society, and this relative position is related to social conditions that are important for health including good early childhood development, access to high quality education, rewarding work with some degree of autonomy, decent housing, and a clean and safe living environment. The social condition of autonomy, control, and empowerment turns are important influences on health and disease, and individuals who lack social participation and control over their lives are at a greater risk for heart disease and mental illness.

International health inequalities

Even in the wealthiest countries, there are health inequalities between the rich and the poor. Researchers Labonte and Schrecker from the Department of Epidemiology and Community Medicine at the University of Ottawa emphasize that globalization is key to understanding the social determinants of health, and as Bushra (2011) posits, the impacts of globalization are unequal. Globalization has caused an uneven distribution of wealth and power both within and across national borders, and where and in what situation a person is born has an enormous impact on their health outcomes. The Organization for Economic Cooperation and Development found significant differences among developed nations in health status indicators such as life expectancy, infant mortality, incidence of disease, and death from injuries. Migrants and their family members also experience significant negatives health impacts.

These inequalities may exist in the context of the health care system, or in broader social approaches. According to the WHO's Commission on Social Determinants of Health, access to health care is essential for equitable health, and it argued that health care should be a common good rather than a market commodity. However, there is substantial variation in health care systems and coverage from country to country. The Commission also calls for government action on such things as access to clean water and safe, equitable working conditions, and it notes that dangerous working conditions exist even in some wealthy countries. In the Rio Political Declaration on Social Determinants of Health, several key areas of action were identified to address inequalities, including promotion of participatory policy-making processes, strengthening global governance and collaboration, and encouraging developed countries to reach a target of 0.7% of gross national product (GNP) for official development assistance.

Theoretical approaches

The UK Black and The Health Divide reports considered two primary mechanisms for understanding how social determinants influence health: cultural/behavioral and materialist/structuralist. The cultural/behavioral explanation is that individuals' behavioral choices (e.g., tobacco and alcohol use, diet, physical activity, etc.) were responsible for their development and deaths from a variety of diseases. However, both the Black and Health Divide reports found that behavioral choices are determined by one's material conditions of life, and these behavioral risk factors account for a relatively small proportion of variation in the incidence and death from various diseases. 

The materialist/structuralist explanation emphasizes the people's material living conditions. These conditions include availability of resources to access the amenities of life, working conditions, and quality of available food and housing among others. Within this view, three frameworks have been developed to explain how social determinants influence health. These frameworks are: (a) materialist; (b) neo-materialist; and (c) psychosocial comparison. The materialist view explains how living conditions – and the social determinants of health that constitute these living conditions – shape health. The neo-materialist explanation extends the materialist analysis by asking how these living conditions occur. The psychosocial comparison explanation considers whether people compare themselves to others and how these comparisons affect health and wellbeing. 

A nation's wealth is a strong indicator of the health of its population. Within nations, however, individual socio-economic position is a powerful predictor of health. Material conditions of life determine health by influencing the quality of individual development, family life and interaction, and community environments. Material conditions of life lead to differing likelihood of physical (infections, malnutrition, chronic disease, and injuries), developmental (delayed or impaired cognitive, personality, and social development), educational (learning disabilities, poor learning, early school leaving), and social (socialization, preparation for work, and family life) problems. Material conditions of life also lead to differences in psychosocial stress. When the fight-or-flight reaction is chronically elicited in response to constant threats to income, housing, and food availability, the immune system is weakened, insulin resistance is increased, and lipid and clotting disorders appear more frequently. 

The materialist approach offers insight into the sources of health inequalities among individuals and nations. Adoption of health-threatening behaviours is also influenced by material deprivation and stress. Environments influence whether individuals take up tobacco, use alcohol, consume poor diets, and have low levels of physical activity. Tobacco use, excessive alcohol consumption, and carbohydrate-dense diets are also used to cope with difficult circumstances. The materialist approach seeks to understand how these social determinants occur. 

The neo-materialist approach is concerned with how nations, regions, and cities differ on how economic and other resources are distributed among the population. This distribution of resources can vary widely from country to country. The neo-materialist view focuses on both the social determinants of health and the societal factors that determine the distribution of these social determinants, and especially emphasizes how resources are distributed among members of a society.

The social comparison approach holds that the social determinants of health play their role through citizens' interpretations of their standings in the social hierarchy. There are two mechanisms by which this occurs. At the individual level, the perception and experience of one's status in unequal societies lead to stress and poor health. Feelings of shame, worthlessness, and envy can lead to harmful effects upon neuro-endocrine, autonomic and metabolic, and immune systems. Comparisons to those of a higher social class can also lead to attempts to alleviate such feelings by overspending, taking on additional employment that threaten health, and adopting health-threatening coping behaviors such as overeating and using alcohol and tobacco. At the communal level, widening and strengthening of hierarchy weakens social cohesion, which is a determinant of health. The social comparison approach directs attention to the psychosocial effects of public policies that weaken the social determinants of health. However, these effects may be secondary to how societies distribute material resources and provide security to its citizens, which are described in the materialist and neo-materialist approaches.

Life-course perspective

Life-course approaches emphasize the accumulated effects of experience across the life span in understanding the maintenance of health and the onset of disease. The economic and social conditions – the social determinants of health – under which individuals live their lives have a cumulative effect upon the probability of developing any number of diseases, including heart disease and stroke. Studies into the childhood and adulthood antecedents of adult-onset diabetes show that adverse economic and social conditions across the life span predispose individuals to this disorder.

Hertzman outlines three health effects that have relevance for a life-course perspective. Latent effects are biological or developmental early life experiences that influence health later in life. Low birth weight, for instance, is a reliable predictor of incidence of cardiovascular disease and adult-onset diabetes in later life. Nutritional deprivation during childhood has lasting health effects as well. 

Pathway effects are experiences that set individuals onto trajectories that influence health, well-being, and competence over the life course. As one example, children who enter school with delayed vocabulary are set upon a path that leads to lower educational expectations, poor employment prospects, and greater likelihood of illness and disease across the lifespan. Deprivation associated with poor-quality neighborhoods, schools, and housing sets children off on paths that are not conducive to health and well-being.

Cumulative effects are the accumulation of advantage or disadvantage over time that manifests itself in poor health, in particular between women and men. These involve the combination of latent and pathways effects. Adopting a life-course perspective directs attention to how social determinants of health operate at every level of development – early childhood, childhood, adolescence, and adulthood – to both immediately influence health and influence it in the future.

Chronic stress and health

Stress is hypothesized to be a major influence in the social determinants of health. There is a relationship between experience of chronic stress and negative health outcomes. This relationship is explained through both direct and indirect effects of chronic stress on health outcomes. 

The direct relationship between stress and health outcomes is the effect of stress on human physiology. The long term stress hormone, cortisol, is believed to be the key driver in this relationship. Chronic stress has been found to be significantly associated with chronic low-grade inflammation, slower wound healing, increased susceptibility to infections, and poorer responses to vaccines. Meta-analysis of healing studies has found that there is a robust relationship between elevated stress levels and slower healing for many different acute and chronic conditions. However, it is also important to note that certain factors, such as coping styles and social support, can mitigate the relationship between chronic stress and health outcomes.

Stress can also be seen to have an indirect effect on health status. One way this happens is due to the strain on the psychological resources of the stressed individual. Chronic stress is common in those of a low socio-economic status, who are having to balance worries about financial security, how they will feed their families, housing status, and many other concerns. Therefore, individuals with these kinds of worries may lack the emotional resources to adopt positive health behaviours. Chronically stressed individuals may therefore be less likely to prioritize their health. 

In addition to this, the way that an individual responds to stress can influence their health status. Often, individuals responding to chronic stress will develop potentially positive or negative coping behaviors. People who cope with stress through positive behaviors such as exercise or social connections may not be as affected by the relationship between stress and health, whereas those with a coping style more prone to over-consumption (i.e. emotional eating, drinking, smoking or drug use) are more likely to be see negative health effects of stress.

The detrimental effects of stress on health outcomes are hypothesised to partly explain why countries that have high levels of income inequality have poorer health outcomes compared to more equal countries. Wilkinson and Picket hypothesise in their book The Spirit Level that the stressors associated with low social status are amplified in societies where others are clearly far better off.

Improving health conditions worldwide

Reducing the health gap requires that governments build systems that allow a healthy standard of living for every resident.

Interventions

Three common interventions for improving social determinant outcomes as identified by the WHO are education, social security and urban development. However, evaluation of interventions has been difficult due to the nature of the interventions, their impact and the fact that the interventions strongly affect children's health outcomes.

1. Education: Many scientific studies have been conducted and strongly suggests that increased quantity and quality of education leads to benefits to both the individual and society (e.g. improved labor productivity). Health and economic outcome improvements can be seen in health measures such as blood pressure, crime, and market participation trends. Examples of interventions include decreasing size of classes and providing additional resources to low-income school districts. However, there is currently insufficient evidence to support education as an social determinants intervention with a cost-benefit analysis.
2. Social Protection: Interventions such as “health-related cash transfers”, maternal education, and nutrition-based social protections have been shown to have a positive impact on health outcomes. However, the full economic costs and impacts generated of social security interventions are difficult to evaluate, especially as many social protections primarily affect children of recipients.
3. Urban Development: Urban development interventions include a wide variety of potential targets such as housing, transportation, and infrastructure improvements. The health benefits are considerable (especially for children), because housing improvements such as smoke alarm installation, concrete flooring, removal of lead paint, etc. can have a direct impact on health. In addition, there is a fair amount of evidence to prove that external urban development interventions such as transportation improvements or improved walkability of neighborhoods (which is highly effective in developed countries) can have health benefits. Affordable housing options (including public housing) can make large contributions to both social determinants of health, as well as the local economy.

The Commission on Social Determinants of Health made recommendations in 2005 for action to promote health equity based on three principles: "improve the circumstances in which people are born, grow, live, work, and age; tackle the inequitable distribution of power, money, and resources, the structural drivers of conditions of daily life, globally, nationally, and locally; and measure the problem, evaluate action, and expand the knowledge base." These recommendations would involve providing resources such as quality education, decent housing, access to affordable health care, access to healthy food, and safe places to exercise for everyone despite gaps in affluence. Expansion of knowledge of the social determinants of health, including among healthcare workers, can improve the quality and standard of care for people who are marginalized, poor or living in developing nations by preventing early death and disability while working to improve quality of life.

Challenges of measuring value of interventions

Many economic studies have been conducted to measure the effectiveness and value of social determinant interventions but are unable to accurately reflect effects on public health due to the multi-faceted nature of the topic. While neither cost-effectiveness nor cost-utility analysis is able to be used on social determinant interventions, cost-benefit analysis is able to better capture the effects of an intervention on multiple sectors of the economy. For example, tobacco interventions have shown to decrease tobacco use, but also prolong lifespans, increasing lifetime healthcare costs and is therefore marked as a failed intervention by cost-effectiveness, but not cost-benefit. Another issue with research in this area is that most of the current scientific papers focus on rich, developed countries, and there is a lack of research in developing countries.

Policy changes that affect children also present the challenge that it takes a significant amount of time to gather this type of data. In addition, policies to reduce child poverty are particularly important, as elevated stress hormones in children interfere with the development of brain circuitry and connections, causing long term chemical damage. In most wealthy countries, the relative child poverty rate is 10 percent or less; in the United States, it is 21.9 percent. The lowest poverty rates are more common in smaller well-developed and high-spending welfare states like Sweden and Finland, with about 5 or 6 percent. Middle-level rates are found in major European countries where unemployment compensation is more generous and social policies provide more generous support to single mothers and working women (through paid family leave, for example), and where social assistance minimums are high. For instance, the Netherlands, Austria, Belgium and Germany have poverty rates that are in the 7 to 8 percent range.

Public policy

The Rio Political Declaration on Social Determinants of Health embraces a transparent, participatory model of policy development that, among other things, addresses the social determinants of health leading to persistent health inequalities for indigenous peoples. In 2017, citing the need for accountability for the pledges made by countries in the Rio Political Declaration on Social Detereminants of Health, the World Health Organization and United Nations Children's Fund called for the monitoring of intersectoral interventions on the social detereminants of health that improve health equity.

The United States Department of Health and Human Services includes social determinants in its model of population health, and one of its missions is to strengthen policies which are backed by the best available evidence and knowledge in the field  Social determinants of health do not exist in a vacuum. Their quality and availability to the population are usually a result of public policy decisions made by governing authorities. For example, early life is shaped by availability of sufficient material resources that assure adequate educational opportunities, food and housing among others. Much of this has to do with the employment security and the quality of working conditions and wages. The availability of quality, regulated childcare is an especially important policy option in support of early life. These are not issues that usually come under individual control but rather they are socially constructed conditions which require institutional responses. A policy-oriented approach places such findings within a broader policy context. In this context, Health in All Policies has seen as a response to incorporate health and health equity into all public policies as means to foster synergy between sectors and ultimately promote health. 

Yet it is not uncommon to see governmental and other authorities individualize these issues. Governments may view early life as being primarily about parental behaviors towards their children. They then focus upon promoting better parenting, assist in having parents read to their children, or urge schools to foster exercise among children rather than raising the amount of financial or housing resources available to families. Indeed, for every social determinant of health, an individualized manifestation of each is available. There is little evidence to suggest the efficacy of such approaches in improving the health status of those most vulnerable to illness in the absence of efforts to modify their adverse living conditions.

A team of the Cochrane Collaboration conducted the first comprehensive systematic review of the health impact of unconditional cash transfers, as an increasingly common up-stream, structural social determinant of health. The review of 21 studies, including 16 randomized controlled trials, found that unconditional cash transfers may not improve health services use. However, they lead to a large, clinically meaningful reduction in the likelihood of being sick by an estimated 27%. Unconditional cash transfers may also improve food security and dietary diversity. Children in recipient families are more likely to attend school, and the cash transfers may increase money spent on health care.

One of the recommendations by the Commission on the Social Determinants of Health is expanding knowledge – particularly to health care workers.

Although not addressed by the WHO Commission on Social Determinants of Health, sexual orientation and gender identity are increasingly recognized as social determinants of health.

Diseases of poverty

From Wikipedia, the free encyclopedia

Diseases of poverty (also known as poverty related diseases) is the term used to describe diseases that are more prevalent in the low-income population. It includes infectious diseases as well as diseases related to malnutrition and poor health behaviors. Poverty is one of the social determinants of health. The World Health Report, 2002 states that diseases of poverty account for 45% of the disease burden in the countries with high poverty rate which are preventable or treatable with exciting interventions. Diseases of poverty are often co-morbid and ubiquitous with malnutrition.

Poverty and diseases are a ramification of each other. Poverty increases chances of having these diseases as the deprivation of safe shelter, drinking water and food, poor sanitation, lack of knowledge and access to health services contributes towards poor health behaviors which often results into diseases of poverty. At the same time, these diseases act as a barrier for economic growth to affected people and families caring for them which in turn results into increased poverty in the community.

These diseases triggered in part by poverty are in contrast to so-called "diseases of affluence", which are diseases thought to be a result of increasing wealth in a society.

Contributing factors

For many environmental and social factors, including poor housing conditions and poor working conditions, inadequate sanitation, and disproportionate occupation as sex workers, the poor are more likely to be exposed to infectious diseases. Malnutrition, mental stress, overwork, inadequate knowledge, and minimal health care can hinder recovery and exacerbate the disease. 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.

Contaminated water

Each year many children and adults die as a result of a lack of access to clean drinking water and poor sanitation. Many poverty related diseases such as diarrhea acquire and spread as a result of inadequate access to clean drinking water. According to UNICEF, 3,000 children die every day, worldwide due to contaminated drinking water and poor sanitation.

Although the Millennium Development Goal (MDG) of halving the number of people who did not have access to clean water by 2015, was reached five years ahead of schedule in 2010, there are still 783 million people who rely on unimproved water sources. In 2010 the United Nations declared access to clean water a fundamental human right, integral to the achievement of other rights. This made it enforceable and justifiable to permit governments to ensure their populations access to clean water. Though access to water has improved for some, it continues to be especially difficult for women and children. Women and girls bear most of the burden for accessing water and supplying it to their households. 

In India, Sub-Saharan Africa, and parts of Latin America, women are required to travel long distances in order to access a clean water source and then bring some water home. This has a significant impact on girls’ educational attainment.

There have been further efforts to improve water quality using new technology which allows water to be disinfected immediately upon collection and during the storage process. Clean water is necessary for cooking, cleaning, and laundry because many people come into contact with disease causing pathogens through their food, or while bathing or washing.

An ongoing issue of contaminated water in the United States has been taking place in Flint, Michigan. On September 4, 2018, evidence of E Coli and other organisms that can cause disease were found in the water. The issue of contaminated water in Flint, Michigan started when the source for drinking water in Flint was changed from the Lake Huron and the Detroit River to the very cheap Flint River.

Inadequate sanitation

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

Standpipes and sanitation are provided in most developing areas, but the death rates are not significantly reduced. One of the reasons that water-related diseases are still occurring is because water supplies can be contacted by contaminated surface water. To effectively decrease the morbidity and mortality of diseases, the population should get access to water from home instead from outside. Therefore, in addition to the installation of standpipes, water supplies and sanitation should be provided within houses.

Poor 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. 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. 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 macro-nutrients and micro-nutrients promotes viral replication that contributes to greater risks of HIV transmission from mother-to-child as well as those through sexual transmission. Increased mother-to-child transmission is related to specific deficiencies in micro-nutrients such as vitamin A. Further, anemia, a decrease in the number of red blood cells, increases viral shedding in the birth canal, which also increases risk of mother-to-child transmission. Without these vital nutrients, the body lacks the defense mechanisms to resist infections. 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.

In the United States, 11.1 percent of households struggle with food insecurity. Food insecurity refers to the lack of access to quality food for a healthy lifestyle. The rate of hunger and malnutrition in female headed households was three times the national average at 30.2 percent. According to the Food and Agriculture Organization of the United Nations, 10 percent of the population in Latin America and the Caribbean are affected by hunger and malnutrition.

Poor housing conditions

Quality and affordability of housing are one of the major concerns in public health. Poor housing conditions can be described as leaks, molds, indoor air pollutant, overcrowding, hazardous structures, affordability of home heating, and poor ergonomics. Housing insecurities are very common among the poor. It is often associated with infectious diseases, lead exposure, injuries, and mental health.

Lack of access to health services

According to WHO, medical strategies report, approximately 30% of the global population does not have regular access to exciting medicines. In the poorest parts of Africa and Asia, this percent goes up to 50%. The population below the poverty line lacks access due to higher retail price and unavailability of the medicines. The higher cost can be due to the higher manufacturing price or due to local or regional tax and Value Added Tax. There is a significant disparity in the research conducted in the health sector. It is claimed that only 10% of the health research conducted globally focuses on 90% disease burden. However, diseases such as cancer, cardiovascular diseases etc that traditionally were associated with the wealthier community are now becoming more prevalent in the poor communities as well. Hence, the research conducted now is relevant to poor population. Political priority is also one of the contributing factors of inaccessibility. The government of poor countries may allocate less funding to public health due to the scarcity of resources.

Diseases

Together, diseases of poverty kill approximately 14 million people annually. Gastroenteritis with its associated diarrhea results in about 1.8 million deaths in children yearly with most of these in the world's poorest nations.

At the global level, the three primary PRDs are tuberculosis, AIDS/HIV and malaria. Developing countries account for 95% of the global AIDS prevalence and 98% of active tuberculosis infections. Furthermore, 90% of malaria deaths occur in sub-Saharan Africa. Together, these three diseases account for 10% of global mortality.

Treatable childhood diseases are another set which have disproportionately higher rates in poor countries despite the availability of cures for decades. These include measles, pertussis and polio. The largest three poverty-related diseases (PRDs) — AIDS, malaria, and tuberculosis — account for 18% of diseases in poor countries. The disease burden of treatable childhood diseases in high-mortality, poor countries is 5.2% in terms of disability-adjusted life years but just 0.2% in the case of advanced countries.

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.

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.

Neglected diseases

Based upon the spread of research in cures for diseases, certain diseases are identified and referred to as "neglected diseases". These include the following diseases:

• African trypanosomiasis
• Chagas disease
• Leishmaniasis
• Lymphatic filariasis
• Dracunculiasis (“Guinea worm disease”)
• Onchocerciasis
• Schistosomiasis
• Trichomoniasis

Tropical diseases such as these tend to be neglected in research and development efforts. Of 1393 new drugs brought into use over a period of 25 years (1975–1999), only a total of thirteen, less than 1%, related to these diseases. Of 20 MNC drug companies surveyed for research on PRDs, only two had projects targeted towards these neglected PRDs. However, the combined total number of deaths due to these diseases is dwarfed by the enormous number of patients affected by PRDs such as respiratory infections, HIV/AIDS, diarrhea and tuberculosis, besides many others. Similar to the spread of tropical neglected diseases in developing nations, these neglected infections disproportionately affect poor and minority populations in the United States. These diseases have been identified by the Centers for Disease Control and Prevention, as priorities for public health action based on the number of people infected, the severity of the illnesses, and the ability to prevent and treat them.

Trichomoniasis

Trichomoniasis is the most common sexually transmitted infection affecting more than 200 million people worldwide. It is especially prevalent among young, poor and African American women. This infection is also common in poor communities in Sub-Saharan Africa and impoverished parts of Asia. This neglected infection is one of special concern because it is associated with a heightened risk for contracting HIV and pre-term deliveries.

In addition, availability of cures and recent advances in medicine have led to only three diseases being considered neglected diseases, namely, African trypanosomiasis, Chagas disease and Leishmaniasis.

Malaria

Africa accounts for a majority of malaria infections and deaths worldwide. Over 80 percent of the 300 to 500 million malaria infections occurring annually worldwide are in Africa. Each year, about one million children under the age of five die from malaria. Children who are poor, have mothers with little to no education, and live in rural areas are more susceptible to malaria and more likely to die from it. Malaria is directly related to the spread of HIV in sub-Saharan Africa. 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. 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. 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. Malaria vaccines are an area of intensive research.

Intestinal parasites

Intestinal parasites are extremely prevalent in tropical areas. 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. 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

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 schistosomiasis live in sub-Saharan Africa. 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. It damages the intestines, bladder, and other organs and can lead to anemia and protein-energy deficiency. Along with malaria, schistosomiasis is one of the most important parasitic co-factors aiding in HIV transmission. Epidemiological data shows schistosome-endemic areas coincide with areas of high HIV prevalence, suggesting that parasitic infections such as schistosomiasis increase risk of HIV transmission.

Tuberculosis

Tuberculosis is the leading cause of death around the world for an infectious disease. This disease is especially prevalent in sub-Saharan Africa, and the Latin American and Caribbean region. While the tuberculosis rate is decreasing in the rest of the world, it is increasing by rate of 6 percent per year in Sub-Saharan Africa. It is the leading cause of death for people with HIV in Africa. Tuberculosis (TB) is closely related to lifestyles of poverty, overcrowded conditions, alcoholism, stress, drug addiction and malnutrition. This disease spreads quickly among people who are undernourished. According to the Center for Disease Control and Prevention, in the United States, tuberculosis is more prevalent among foreign born persons, and ethnic minorities. The rates are especially high among Hispanics, Blacks and Asians. HIV infection and TB are also closely tied. Being infected with HIV increases the rate of activation of latent TB infections, and having TB, increases the rate of HIV replication, therefore accelerating the progression of AIDS.

AIDS

AIDS is a disease of the human immune system caused by the human immunodeficiency virus (HIV). Primary modes of HIV transmission in sub-Saharan Africa are sexual intercourse, mother-to-child transmission (vertical transmission), and through HIV-infected blood. Since rate of HIV transmission via heterosexual intercourse is so low, it is insufficient to cause AIDS disparities between countries. 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. In these developing countries, especially those in sub-Saharan Africa, certain health factors predispose the population to HIV infections.

Many of the countries in Sub-Saharan Africa are ravaged with poverty and many people live on less than one United States dollar a day. The poverty in these countries gives rise to many other factors that explain the high prevalence of AIDS. The poorest people in most African countries suffer from malnutrition, lack of access to clean water, and have improper sanitation. Because of a lack of clean water many people are plagued by intestinal parasites that significantly increase their chances of contracting HIV due to compromised immune system. Malaria, a disease still rampant in Africa also increases the risk of contracting HIV. These parasitic diseases, affect the body’s immune response to HIV, making people more susceptible to contracting the disease once exposed. Genital schistosomiasis, also prevalent in the topical areas of Sub-Saharan Africa and many countries worldwide, produces genital lesions and attract CD4 cells to the genital region which promotes HIV infection. All these factors contribute to the high rate of HIV in Sub-Saharan Africa. Many of the factors seen in Africa are also present in Latin America and the Caribbean and contribute to the high rates of infections seen in those regions. In the United States, poverty is a contributing factor to HIV infections. There is also a large racial disparity, with African Americans having a significantly higher rate of infection than their white counterparts.

Asthma

More than 300 million people worldwide have asthma. The rate of asthma increases as countries become more urbanized and in many parts of the world those who develop asthma do not have access to medication and medical care. Within the United States, African Americans and Latinos are four times more likely to suffer from severe asthma than whites. The disease is closely tied to poverty and poor living conditions. Asthma is also prevalent in children in low income countries. Homes with roaches and mice, as well as mold and mildew put children at risk for developing asthma as well as exposure to cigarette smoke.

Unlike many other Western countries, the mortality rate for asthma has steadily risen in the United States over the last two decades. Mortality rates for African American children due to asthma are also far higher than that of other racial groups. For African Americans, the rate of visits to the emergency room is 330 percent higher than their white counterparts. The hospitalization rate is 220 percent higher and the death rate is 190 percent higher. Among Hispanics, Puerto Ricans are disproportionately affected by asthma with a disease rate that is 113 percent higher than non-Hispanic Whites and 50 percent higher than non-Hispanic Blacks. Studies have shown that asthma morbidity and mortality are concentrated in inner city neighborhoods characterized by poverty and large minority populations and this affects both genders at all ages. Asthma continues to have an adverse effects on the health of the poor and school attendance rates among poor children. 10.5 million days of school are missed each year due to asthma.

Cardiovascular disease

Though heart disease is not exclusive to the poor, there are aspects of a life of poverty that contribute to its development. This category includes coronary heart disease, stroke and heart attack. Heart disease is the leading cause of death worldwide and there are disparities of morbidity between the rich and poor. Studies from around the world link heart disease to poverty. Low neighborhood income and education were associated with higher risk factors. Poor diet, lack of exercise and limited (or no) access to a specialist were all factors related to poverty, though to contribute to heart disease. Both low income and low education were predictors of coronary heart disease, a subset of cardiovascular disease. Of those admitted to hospital in the United States for heart failure, women and African Americans were more likely to reside in lower income neighborhoods. In the developing world, there is a 10 fold increase in cardiac events in the black and urban populations.

Obstetrical fistula

Obstetric fistula or vaginal fistula is a medical condition in which a fistula (hole) develops between either the rectum and vagina or between the bladder and vagina after severe or failed childbirth, when adequate medical care is not available. It is considered a disease of poverty because of its tendency to occur women in poor countries who do not have health resources comparable to developed nations.

Dental decay

Dental decay or dental caries is the gradual destruction of tooth enamel. Poverty is a significant determinant for oral health. Dental caries is one of the most common chronic diseases worldwide. In the United States it is the most common chronic disease of childhood. Risk factors for dental caries includes living in poverty, poor education, low socioeconomic status, being part of an ethnic minority group, having a developmental disability, recent immigrants and people infected with HIV/AIDS. In Peru, poverty was found to be positively correlated with dental caries among children. According to a report by U.S health surveillance, tooth decay peaks earlier in life and is more severe in children with families living below the poverty line. Tooth decay is also strongly linked to dietary behaviors, and in poor rural areas where nutrient dense foods, fruits and vegetables are unavailable, the consumption of sugary and fatty food increases the risk of dental decay. Because the mouth is a gateway to the respiratory and digestive tracts, oral health has a significant impact on other health outcomes. Gum disease has been linked to diseases such as cardiovascular disease.

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”.

For women

Women and children are often put at a high risk of being infected by schistosomiasis, which in turn puts them at a higher risk of acquiring HIV. Since the mode of schistosomiasis 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. Women who have schistosomiasis lesions are three times more likely to be infected with HIV.

Women also have a higher risk of HIV transmission through the use of medical equipment such as needles. Because more women than men use health services, especially during pregnancy, they are more likely to come across unsterilized needles for injections. 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. 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. 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.

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. HIV can negatively affect work output, which impacts the ability to generate income. 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.

Public policy proposals

There are a number of proposals for reducing the diseases of poverty and eliminating health disparities within and between countries. The World Health Organization proposes closing the gaps by acting on social determinants. Their first recommendation is to improve daily living conditions. This area involves improving the lives of women and girls so that their children are born in healthy environments and placing an emphasis on early childhood health. Their second recommendation is to tackle the inequitable distribution of money, power and resources. This would involve building stronger public sectors and changing the way in which society is organized. Their third recommendation is to measure and understand the problem and assess the impact of action. This would involve training policy makers and healthcare practitioners to recognize problems and form policy solutions.

Health in All Policies

The 8th Global Conference on Health Promotion held in Helsinki in June 2013 has proposed an approach termed Health in All Policies. Health inequalities are shaped by many powerful forces and social, political, and economic determinants. Governments have a responsibility to ensure that their people are able to live healthy lives and have equitable access to achieving a reasonable state of good health. Policies that governments craft and implement in all sectors have a significant and ongoing impact on public health, health equity, and the lives of their citizens. Increases in technology, medical innovation, and living conditions have led to the disappearance of diseases and other factors contributing to poor health. However, there are many diseases of poverty that still persist in developed and developing countries. Tackling these health inequalities and diseases of poverty requires a willingness to engage the whole government in health. The Helskinki Statement lays out a framework of action for countries and calls on governments to make a commitment to building health equity within their country. 

Health in All Policies (HiAP) is an approach to public policies across all sectors of government that takes into account the health implications of all government and policy decisions to improve health equity across all populations residing within the borders of a country. This concept is built upon principles in line with the Universal Declaration of Human Rights, The United Nations Millennium Development Declaration, and principles of good governance: legitimacy given by national and international law, accountability of government, transparency of policy making, participation of citizens, sustainability ensuring policies meet the needs of both present and future generations, and collaboration across sectors and levels of government. 

Finally the Framework lists and expands upon six steps for implementation that may be undertaken by a country in taking action towards Health in All Policies. These are components of action and not a rigid checklist of steps to adhere to. The most important aspect of this policy is that governments should adapt the policy to suit the needs of their citizens, their socioeconomic situation, and their governance system.

1. Establish the need and priorities for HiAP
2. Frame planned action
3. Identify supportive structures and processes
4. Facilitate assessment and engagement
5. Ensure monitoring, evaluation, and reporting
6. Build capacity.

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. Micro-nutrients 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 $0.08 if provided daily.
• Eliminating Co-factors: Tackling the very diseases that increase risk of HIV infections can help slow down the rates of HIV transmission. Co-factors 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. 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.

Diseases of affluence

From Wikipedia, the free encyclopedia

Diseases of affluence is a term sometimes given to selected diseases and other health conditions which are commonly thought to be a result of increasing wealth in a society. Also referred to as the "Western disease" paradigm, these diseases are in contrast to so-called "diseases of poverty", which largely result from and contribute to human impoverishment. These diseases of affluence have vastly increased in prevalence since the end of World War II.

Examples of diseases of affluence include mostly chronic non-communicable diseases (NCDs) and other physical health conditions for which personal lifestyles and societal conditions associated with economic development are believed to be an important risk factor — such as type 2 diabetes, asthma, coronary heart disease, cerebrovascular disease, peripheral vascular disease, obesity, hypertension, cancer, alcoholism, gout, and some types of allergy. They may also be considered to include depression and other mental health conditions associated with increased social isolation and lower levels of psychological well being observed in many developed countries. Many of these conditions are interrelated, for example obesity is thought to be a partial cause of many other illnesses.

In contrast, the diseases of poverty have tended to be largely infectious diseases, or the result of poor living conditions. These include tuberculosis, malaria, and intestinal diseases. Increasingly, research is finding that diseases thought to be diseases of affluence also appear in large part in the poor. These diseases include obesity and cardiovascular disease and, coupled with infectious diseases, these further increase global health inequalities.

Diseases of affluence started to become more prevalent in developing countries as diseases of poverty decline, longevity increases, and lifestyles change. In 2008, nearly 80% of deaths due to NCDs — including heart disease, strokes, chronic lung diseases, cancers and diabetes — occurred in low- and middle-income countries.

Top ten causes of death in high income/affluent countries

According to World Health Organization (WHO) the top 10 causes of deaths in the high income countries/ affluent countries in 2016 were from

1. Ischemic heart diseases
2. Stroke
3. Alzheimer disease and other dementia
4. Trachea, bronchus and lung cancer
5. Chronic obstructive pulmonary disease
6. Lower respiratory infections
7. Colon and rectum cancers
8. Diabetes
9. Kidney diseases
10. Breast cancer

Except for the lower respiratory infections all of them are non-communicable diseases. In 2016 WHO reported 56.9 million deaths worldwide, and more than half (54%), were due to the top causes of death previously mentioned.

Causes

Factors associated with the increase of these conditions and illnesses appear to be things that are a direct result of technological advances. They include:

• Less strenuous physical exercise, often through increased use of motor vehicles
• Irregular exercise as a result of office jobs involving no physical labor.
• Easy accessibility in society to large amounts of low-cost food (relative to the much-lower caloric food availability in a subsistence economy)
  • More food generally, with much less physical exertion expended to obtain a moderate amount of food
  • Higher consumption of vegetable oils and high sugar-containing foods
  • Higher consumption of meat and dairy products
  • Higher consumption of refined flours and products made of such, like white bread or white noodles
  • More foods which are processed, cooked, and commercially provided (rather than seasonal, fresh foods prepared locally at time of eating)
• Prolonged periods of little activity
• Greater use of alcohol and tobacco
• Longer life-spans
  • Reduced exposure to infectious agents throughout life (this can result in a more idle and inexperienced immune system as compared to an individual who experienced relatively frequent exposure to certain pathogens in their time of life)
• Increased cleanliness. The hygiene hypothesis postulates that children of affluent families are now exposed to fewer antigens than has been normal in the past, giving rise to increased prevalence of allergy and autoimmune diseases.

Diabetes mellitus

Diabetes is a chronic metabolic disease characterized by increase blood glucose level. Type 2 diabetes is the most common form of diabetes. It is caused by resistance to insulin or the lack of production of insulin. It is seen most commonly in adults. Type 1 diabetes or juvenile diabetes affects mostly children. This condition is due to little or lack of insulin production from the pancreas.

According to WHO the prevalence of diabetes has quadrupled from 1980 to 422 million adults. The global prevalence of diabetes has increased from 4.7% in 1980 to 8.5% in 2014. Diabetes has been a major cause for blindness, kidney failure, heart attack, stroke and lower limb amputation.

Prevalence in countries of affluence

The Centers of Disease Control and Prevention (CDC) released a report in 2015 indicating that more than 100 million Americans have diabetes or pre-diabetes. Diabetes was the seventh leading cause of death in United States in 2015. In developed countries like the United States, the risk for diabetes is seen in people with low socioeconomic status (SES). Socioeconomic status is defined by the education and the income level of a person. The prevalence of diabetes varies by education level. Of those diagnosed with diabetes:12.6% of adults had less than a high school education, 9.5% had a high school education and 7.2% had more than high school education.

Differences in diabetes prevalence are seen in the population and ethnic groups in USA. Diabetes is more common in non-Hispanic whites, who are less educated and have a lower income. It is also more common in less educated Hispanics. The highest prevalence of diabetes is seen in the southeast, southern and Appalachian portion of the United States. In the United States the prevalence of diabetes is increasing in children and adolescents. In 2015, 25 million people were diagnosed with diabetes, of which 193,000 were children. The total direct and indirect cost of diagnosed diabetes in US in 2012 was $245 billion.

In 2009, the Canadian Diabetes Association (CDA) estimated that diagnosed diabetes will increase from 1.3 million in 2000 to 2.5 million in 2010 and 3.7 million in 2020. Diabetes was the 7th leading cause of death in Canada in 2015. Like United States, diabetes in more prevalent in the low socioeconomic group of people in Canada.

According to the International Diabetes Federation, more than 58 million people are diagnosed with diabetes in the European Union Region (EUR), and this will go up to 66.7 million by 2045. Similar to other affluent countries like America and Canada, diabetes is more prevalent in the poorer parts of Europe like Central and Eastern Europe.

In Australia according to self-reported data, 1 in 7 adults or approximately 1.2 million people had diabetes in 2014-2015. People who were living in remote or socioeconomically disadvantaged areas were 4 times more likely to develop type 2 diabetes as compared to non-indigenous Australians. Australia incurred $20.8 million in direct costs towards hospitalization, medication, and out-patient treatment towards diabetes. In 2015, $1.2 billion were lost in Australia's Gross Domestic Product (GDP) due to diabetes.

In these countries of affluence, diabetes is prevalent in low socioeconomic groups of people as there is abundance of unhealthy food choices, high energy rich food, and decreased physical activity. More affluent people are typically more educated and have tools to counter unhealthy foods, such as access to healthy food, physical trainers, and parks and fitness centers.

Risk factors

Obesity and being overweight is one of the main risk factors of type 2 diabetes. Other risk factors include lack of physical activity, genetic predisposition, being over 45 years old, tobacco use, high blood pressure and high cholesterol. In United States, the prevalence of obesity was 39.8% in adults and 18.5% in children and adolescents in 2015-2016. In Australia in 2014-2015, 2 out 3 adults or 63% were overweight or obese. Also, 2 out of 3 adults did little or no exercise. According to the World Health Organization, Europe had the 2nd highest proportion of overweight or obese people in 2014 behind America.

In developing countries

According to WHO the prevalence of diabetes is rising more in the middle and low income countries. Over the next 25 years, the number of people with diabetes in developing countries will increase by over 150%. Diabetes is typically seen in people above the retirement age in developed countries, but in developing countries people in the age of 35-64 are mostly affected. Although, diabetes is considered a disease of affluence affecting the developed countries, there is more loss of life and premature death among people with diabetes in the developing countries. Asia accounts for 60% of the world's diabetic population. In 1980 less than 1% of Chinese adults were affected by diabetes, but by 2008 the prevalence was 10%. It is predicted that by 2030 diabetes may affect 79.4 million people in India, 42.3 million people in China and 30.3 million in United States.

These changes are the result of developing nations having rapid economic development. This rapid economic development has caused a change in the lifestyle and food habits leading to over-nutrition, increased intake of fast food causing increase in weight, and insulin resistance. Compared to the west, obesity in Asia is low. India has very low prevalence of obesity, but a very high prevalence of diabetes suggesting that diabetes may occur at a lower BMI in Indians as compared to the Europeans. Smoking increases the risk for diabetes by 45%. In developing countries around 50-60 % adult males are regular smokers, increasing their risk for diabetes. In developing countries, diabetes is more commonly seen in the more urbanized areas. The prevalence of diabetes in rural population is 1/4th that of urban population for countries like India, Bangladesh, Nepal, Bhutan and Sri Lanka.

Cardiovascular disease

Cardiovascular disease refers to a disease of the heart and blood vessels. Conditions and diseases associated with heart disease include: stoke, coronary heart disease, congenital heart disease, heart failure, peripheral vascular disease, and cardiomyopathy. Cardiovascular disease is known as the world's biggest killer. 17.5 million people die from it each year, which equals 31% of all deaths. Heart disease and stroke cause 80% of these deaths.

Risk factors

High blood pressure is the leading risk factor for cardiovascular disease and has contributed to 12% of the cardiovascular related deaths worldwide. Other significant risk factors for heart disease include high cholesterol and smoking. 47% of all Americans have one of these three risk factors. Lifestyle choices, such as poor diet and physical inactivity, and excessive alcohol use can also contribute to cardiovascular disease. Medical conditions, like diabetes and obesity can also be risk factors.

Prevalence in countries of affluence

In the United States, 610,000 people die every year from heart disease which is equal to 1 in 4 deaths. The leading cause of death for both men and women in the United States is heart disease. In Canada, heart disease is the second leading cause of death. In 2014, it was the cause of death for 51,000 people. In Australia, heart disease is also the leading cause of death. 29% of deaths in 2015, had an underlying cause of heart disease. Heart disease causes one in four premature deaths in the United Kingdom and in 2015 heart disease caused 26% of all deaths in that country.

People of lower socio-economic status are more likely to have cardiovascular disease than those who have a higher socio-economic status. This inequality gap has occurred in developed countries because people who have a lower socio-economic status often face many of the risk factors of tobacco and alcohol use, obesity as well as having a sedentary lifestyle. Further social and environmental factors such as poverty, pollution, family history, housing and employment contribute to this inequality gap and to risk of having a health condition caused by cardiovascular disease. The increasing inequality gap between the higher and lower income populations continues in countries such as Canada, despite the availability of health care for everyone.

Alzheimer's disease and other forms of dementia

Dementia is a chronic syndrome which is characterized by deterioration in the thought process beyond what is expected from normal aging. It affects the persons memory, thinking, orientation, comprehension, behavior and ability to perform everyday activity. There are many different forms of dementia . Alzheimer is the most common form which contributes to 60-70 % of the dementia cases. Different forms of dementia can co-exist.Young onset dementia which occurs in individuals before the age of 65 contributes to 9% of the total cases. It is the major cause of disability and dependency among old people.

Worldwide, there are 50 million people who are suffering from dementia and every year 10 million new cases are being reported. The total number of people with dementia is projected to reach 82 million by 2030 and 152 million in 2050 .

Prevalence in countries of affluence

According to CDC, Alzheimer is the 6th leading cause of death in U.S adults and 5th leading cause of death in adults over the age of 65. In 2014, 5 million Americans above the age of 65 were diagnosed with Alzheimer. This number is predicted to triple by the year 2060 and reach up to 14 million. Dementia and Alzheimer has been shown to go unreported on death certificates, leading to under representation of the actual mortality caused by these diseases. Between 2000 and 2015, mortality due to cardiovascular diseases has decreased by 11%, where as death from Alzheimer has increased by 123%. 1 in 3 people over the age of 65 die from Alzheimer or other forms of dementia. Furthermore, 200,000 individuals have been affected by young onset dementia. In United States, Alzheimer affects more women than men. It is twice more common in African-Americans and Hispanics than in whites. As the number of older Americans increases rapidly, the number of new cases of Alzheimer will rise too. 

East Asia has the most people living with dementia (9.8 million) followed by Western Europe (7.5 million ), South Asia (5.1 million) and North America (4.8 million).  In 2016, the prevalence of Alzheimer was 5.05% in Europe. Like in United States, it is more prevalent in women than in men. In the European Union, Finland has the highest mortality among both men and women due to dementia. In Canada, over half a million people are living with dementia. It is projected that by 2031 the number will go up by 66% to 937,000. Every year 25,000 new cases of dementia are diagnosed. 

Dementia is the second leading cause of death in Australia. In 2016, it was the leading cause of deaths in females. In Australia 436,366 people are living with dementia in 2018. 3 in 10 people over the age of 85 and 1 in 10 people over the age of 65 have dementia. It is the single greatest cause of disability in older Australians. Rates of dementia are higher for indigenous people. In people from the northern territory and western Australia the prevalence of dementia is 26 times higher in the 45-69 year old group and about 20 times greater in 60-69 year old group.

Risk factors in countries of affluence

The risk factors for developing dementia or Alzheimer's include age, family history, genetic factors, environmental factors, brain injury, viral infections,neurotoxic chemicals, and various immunological and hormonal disorders.

A new research study has found an association between the affluence of a country, hygiene conditions and the prevalence of Alzheimer in their population. According to the Hygiene Hypothesis, affluent countries with more urbanized and industrialized areas have better hygiene, better sanitation, clean water and improved access to antibiotics. This reduces the exposure to the friendly bacteria, virus and other microorganisms that help stimulate our immune system. Decreased microbial exposure leads to immune system that is poorly developed, which exposes the brain to inflammation as is seen in Alzheimer's disease.

Countries like the UK and France that have access to clean drinking water, improved sanitation facilities and have a high GDP show a 9% increase in Alzheimer's disease as opposed to countries like Kenya and Cambodia. Also countries like UK and Australia, where three quarters of their population lives in urban areas, have a 10% higher Alzheimer's rate than in countries like Bangladesh and Nepal where less than one tenth of their population live in urban areas.

Alzheimer's risk changes with the environment. Individuals from the same ethnic background living in an area of low sanitation will have a lower risk as compared to the same individuals living in an area of high sanitation who will be exposed to a higher risk of developing Alzheimer's. An African-American in U.S. has a higher risk of developing Alzheimer's as compared to one living in Nigeria. Immigrant populations exhibit Alzheimer disease rates intermediate between their home country and adopted country. Moving from a country of high sanitation to a country of low sanitation reduces the risk associated with the disease.

Mental illness

People that face poverty have more risks related to having a mental illness and also do not have as much access to treatment. The stressful events that they face, unsafe living condition and poor physical health lead to cycle of poverty and mental illness that is seen all over the world. According to the World Health Organization 76%-85% of people living in lower and middle income countries are not treated for their mental illness. For those in higher-income counties, 35%-50% of people with mental illness do not receive treatment. It is estimated that 90% of deaths by suicide are caused by substance use disorders and mental illness in higher income countries. In lower to middle income countries, this number is lower.

Prevalence of mental illness

One in four people have experienced mental illness at one time in their lives and approximately 450 million people in the world currently have a mental illness. People that face poverty have more risks related to having a mental illness and also do not have as much access to treatment. The stressful events that they face, unsafe living condition and poor physical health lead to cycle of poverty and mental illness that is seen all over the world. India, China, and the United States are the countries with the highest levels of mental illnesses of anxiety, depression and schizophrenia according to WHO. The U.S. is reported to have the highest level of depression worldwide. In the U.S., approximately one in five adults has a mental illness or 44.7 million people. In 2016, it was estimated that 268 million people in the world had depression. The range of people that have depression by country is from 2% to 6% of the population with the United States, Greenland, and Australia having higher rates of depression. Anxiety disorders, such as generalized anxiety, Obsessive Compulsive Disorder, and Post Traumatic Stress Disorder impacted 275 million people around the world in 2016. The range of population impacted by anxiety disorders globally is from 2.5%-6.5%. Countries, such as the Australia, the United States, Brazil, Argentina, Iran, the United States and a number of countries in Western Europe appear to have a higher prevalence of anxiety disorders.

Cancer

Cancer is a generic term for a large group of disease which is characterized by rapid creation of abnormal cells that grow beyond their usual boundaries. These cells can invade adjoining parts of the body and spread to other organs causing metastases, which is a major cause of death. According to WHO, Cancer is the second leading cause of death globally. One in six deaths worldwide are caused due to cancer, accounting to a total of 9.6 million deaths in 2018.Tracheal, bronchus, and lung cancer is the leading form of cancer deaths across most high and middle-income countries.

Prevalence in countries of affluence

In United States, 1,735,350 new cases of cancer will be diagnosed in 2018. Most common forms of cancer are cancer of the breast, lung, bronchus, prostrate, colorectal cancer, melanoma of skin, Non-Hodgkin's lymphoma, renal cancer, thyroid cancer and liver cancer. Cancer mortality is higher among men than in women. African-Americans have the highest risk of mortality due to cancer. Cancer is also the leading cause of death in Australia. The most common cancers in Australia are prostrate, breast, colorectal, melanoma and lung cancer. These account for 60% of the cancer cases diagnosed in Australia.

Europe contains only 1/8 of the world population, but has around one quarter of the global cancer cases, with 3.7 million new cases each year. Lung, breast, stomach, liver, colon are the most common cancers in Europe. The overall incidences among different cancers vary across countries.

About one in two Canadians will develop cancer in their lifetime, and one in four will die of the disease. In 2017, 206,200 new cases of cancer were diagnosed. Lung, colorectal, breast, and prostate cancer accounted for about half of all cancer diagnoses and deaths.

Risk factors

High prevalence of cancer in high-income countries is attributed to lifestyle factors like obesity, smoking, physical inactivity, diet and alcohol intake. Around 40% of the cancers can be prevented by modifying these factors.

Allergy/Autoimmune diseases

The rate of allergies around the world has risen in industrialized nations over the past 50 years. A number of public health measures, such as sterilized milk, use of antibiotics and improved food production have contributed to a decrease in infections in developed countries. There is a proposed causal relationship, known as the "hygiene hypothesis" that indicates that there are more autoimmune disorders and allergies in developed countries with fewer infections. In developing countries, it is assumed that the rates of allergies are lower than developed countries. That assumption may not be accurate due to limited data on prevalence. Research has found an increase in asthma by 10% in countries such as Peru, Costa Rica, and Brazil.