Explain how biological and cultural variations have affected the susceptibility of humans to infectious diseases and how this interplay has influenced the different prevalence rates of infectious diseases around the world.
The susceptibility to infectious diseases around the world is influenced by cultural and biological factors. Social and economic determinants of health may influence one’s ability to access health care services.1 Physical environment such as cleanliness and housing conditions may also affect the transmission and prevalence of infectious diseases1. Genetic or biological factors can also play a role in one’s susceptibility to an infectious disease.1 Many cultural factors and some biological factors affect many infectious diseases in the similar ways; therefore, this paper will focus on the factors that affect the susceptibility and prevalence or tuberculosis.
Tuberculosis is second to HIV/AIDS as the greatest killer due to a single infectious agent and kills almost 2 million people a year.2,3 Tuberculosis is an infectious disease caused by the bacteria Mycobacterium tuberculosis, which most commonly affects the lungs but can also affect any other organ in the body.2 It is a contagious air borne disease that is transmitted from person to person through droplets from the throat a lungs of people with the active disease – this can occur through coughing, sneezing, spitting. Early diagnosis and treatment is effective in reducing mortality and morbidity of tuberculosis, saving up to 37 million lives between 2000 and 2013.2 As with many other infectious diseases, developing countries have the highest burden of disease with up to 95% of cases being found in these areas.2 Since the spread of tuberculosis requires a susceptible host and an environment that facilitates transmission, therefore any risk factor must increase exposure, susceptibility or both. This paper will cover these risk factors, some of which include having HIV, tobacco use and being male. This paper will first cover some cultural factors affecting the susceptibility of tuberculosis then it will go on to cover some biological factors.
For the purpose of this paper, cultural factors will include social, economic, political and environmental factors. Environmental factors include living and the physical environment as well as the accessibility and distribution of health care services. Cultural and social factors impact the way in which patients perceive health and affect the time in which they seek treatment. Social factors may include risky health behaviours, which increase risk of developing tuberculosis. Economic factors include an individual’s or country’s ability to afford health care.
Tuberculosis is spread when a person with active respiratory tuberculosis coughs of sneezes the bacterium, Mycobacterium tuberculosis, in the air.2 The aerosolized droplets with the bacterium settles very slowly and can remain in the air for many hours, thus increasing its exposure and making it a contagious infections disease.4 As the density of the bacterium in the air increases, so does the risk of infection.4 Developing countries tend to have overcrowded housing and poor ventilation, which leads to increased risk for susceptible persons.4
The prevalence of tuberculosis is approximately twice as high in men as it is in women and there are some cultural or behavioral explanations for this.5 Tobacco smoking is a risk factor for tuberculosis and according to WHO, it is estimated that more than 20% of global tuberculosis incidence may be attributable to smoking.6 It has been hypothesized that cigarette smoke may compromise the pulmonary defense mechanism, which may result in airways that are more susceptible to infection.4 The link between smoking and tuberculosis may also be a reflection of poorer health behaviors in general, leading them to being at higher risk of all diseases.4 Since smoking is more prevalent in males especially in developing countries, then
