How are we to account for the link between social conditions and morbidity and mortality from tuberculosis? Debates surrounding this topic typify and probably are responsible for many of our ideas on disease causation. Let’s consider the four most prominent ideas: genetic susceptibility, social misery, infection with the tubercle bacillus and its variants and poor compliance with treatment. First, we did not need the developments of molecular biology and the human genome project for medical science to speculate on genetic causes of variation in disease susceptibility.
In the last century in the American South, the higher tuberculosis rate in blacks than whites was thought to be due to differential susceptibility that was genetically determined. Then still, in the 19th century. American scientists posited an alternative to the hereditarian view: excessive TB mortality rates were attributed to general areas of sections of cities they had crowed conditions of dwellings along with insufficient nourishment and other influences of poverty. Tuberculosis is usually a disease of poverty, associated with poor nutrition, overcrowding and inadequate health care.
Recently cases of TB in the Western world have been increasing, often in poor inner-city neighborhoods, and sometimes in association with AIDS or other diseases. In 1998 it was estimated that by the year 2000, some 1. 4 million cases of tuberculosis would be associated with HIV infection. However, figures from the year 2000 indicated that only about nine percent of all new TB cases in adults were actually attributed to HIV infection, but the proportion was much greater in the African region.
Attempts to treat TB and control its spread have encountered a number of social and cultural problems. The two main barriers to successful control are a delay in seeking treatment and the abandonment of treatment before it becomes effective. Cultural beliefs about the significance of early symptoms of the disease play a particularly important part. Many wait for months before seeking medical attention. Some misinterpreted their early symptoms as evidence of less serious conditions.
Many attributed their fatigue and weight loss to hard work and lack of sleep and self medicating for results. Another reason for delayed treatment is the stigma associated with the disease in many parts of the world. A study among the Zulu in South Africa found that to suggest that suffers from TB were infectious was a way to identifying them as witches or sorcerers, since these were the only people in the community with the power to cause illness to other people.
Other reasons for failure relate to the health care system itself and the ways that TB clinics are organized. Some examples arranging appointments at inconvenient times, repeating registration of patients at every visit, seating people in overcrowded and poorly ventilated waiting rooms may all contribute to people’s reluctance to come to a clinic for treatment or follow up. The unequal distribution of wealth and resources and of access to health care facilities both between countries and within each country itself can also lead to this situation.
Health could clearly be correlated with income, and people in the poorer social classes had more illness and a much higher mortality than their fellow citizens in the more affluent classes. In many Western societies these disparities are particularly evident in ethnic or cultural minority groups, whether they are immigrants or native born. In the USA, several studies indicate that members of minority groups suffer disproportionately from conditions such as heart disease, diabetes, asthma, cancer and other diseases.
The reasons for these health disparities are complex and include the many effects of poverty, but also the biases and lack of flexibility of the health care system itself. Poor health is usually associated with low income and poverty, since this influences the sort of food, water, clothing, sanitation, housing and medical care that people are able to afford. Health disparities and the physical environment in which poorer communities live can directly impact their health resulting in an inability to afford a clean water supply or adequate sewerage disposal.
The effects of social inequality on health and life expectancy can also apply to affluent societies; that is deprivation can be relative as well as absolute, The lower the social ranking the higher the health risks. This social gradient in health seems to be found in all societies, rich and poor, where hierarchy or social inequality is a feature. Factors such as income or level of education played a part in this, but so did the subjective sense of control that people had over their particular life circumstances both at home and work.
When poorer societies undergo rapid economic and social development, the health of many of their citizens may improve, but that of others may deteriorate. Those groups who remained at a lower socioeconomic level seemed to maintain a healthier lifestyle, leading a more active life and eating more natural foods such as fruits and vegetables and grains. This phenomenon of lifestyle transitions in poorer developing countries may partly explain why nutrition related non-communicable diseases are more prevalent in the developing world among people with a higher socioeconomic status whereas the opposite is found in developed societies.