Public Health and Disease Prevention

Posted on Sep 5, 2024 in Medicine & Health

Health Promotion: Public Health

1) The Concept of Public Health

Public health, a vital component of the healthcare system, is defined as the organized efforts of a community to achieve and maintain optimal health for its members. It involves various activities, including health promotion, advocacy, environmental sanitation, food hygiene, and actions focused on both individuals and the collective population. Public health also encompasses health restoration through primary and hospital care. These actions address diverse issues such as occupational hazards, childhood immunizations, waste management, and combating diseases like AIDS.

Characteristics of Public Health:

Emphasizes a social approach to health.
Considers the interplay between environmental factors, human biology, and individual health status.
Is multidisciplinary, drawing upon advancements in various fields such as anthropology, demography, ecology, economics, epidemiology, physics, engineering, mathematics, medicine, psychology, chemistry, and sociology.

2) Health and Disease

Disease is characterized by the subjective feeling or objective presence of physical or psychological ailments. While the absence of disease is often considered a basic definition of health, the World Health Organization defines health as a state of complete physical, mental, and social well-being, encompassing not only the absence of disease but also the ability to function effectively in daily life, work, and social interactions.

The distinction between health and disease is not always clear-cut, as there is a gradual transition between perfect well-being and death. There is a neutral zone where it can be challenging to differentiate between normal and abnormal states. Furthermore, health status is dynamic, fluctuating throughout life as individuals experience periods of wellness and illness. We constantly move along a continuum of health and disease, rarely reaching either extreme.

3) Natural History of Disease

The transition from a state of general health to disease involves several phases. Pathogens, when they interact with a healthy individual, can disrupt the body’s balance, leading to illness. Initially, there may be no noticeable signs or symptoms. As the disease progresses, symptoms emerge, eventually prompting the individual to seek medical attention. The outcome of this process can vary, ranging from complete recovery to persistent health issues (sequelae or chronic illness) or even death.

Pathogen -> Healthy State -> Asymptomatic Phase -> First Symptoms -> Illness -> Recovery, Sequelae, Chronic Illness, Death -> Initiation of a New Cycle

4) Factors Influencing Health

Diseases often have multiple contributing factors. Even in the case of infections, not everyone exposed to the same pathogen will develop the illness. The severity and manifestation of a disease depend on various factors, including:

Primary Cause: The agent directly responsible for the disease (e.g., a microbe in an infection).
Predisposing Causes: Factors that exist beforehand and either enable the primary cause or increase susceptibility to it (e.g., malnutrition weakening the immune system).
Triggering Causes: Factors that initiate or exacerbate the disease.

Classification of the Causes of Disease:

This classification is valuable for health planning purposes. Causes of disease can be categorized as follows:

Causes related to human biology: Genetic information, age, and sex.
Causes related to the environment: Physical, chemical, and biological contamination, as well as the social environment.
Causes related to lifestyle: Drug use, lack of physical exercise, nutrition, violence, reckless driving, and inappropriate use of healthcare.
Influence of the healthcare system: Coverage or access, cost, and quality of healthcare services.

4.1) Human Biology

Genetic Information: Some diseases are more prevalent in one sex than the other. For example, osteoporosis is more common in women, while myocardial infarction and alopecia are more common in men. Genetic factors can also cause diseases such as color blindness and hemophilia. In some cases, heredity confers a predisposition to diseases like diabetes, obesity, and hypertension.
Age: Certain diseases are characteristic of specific age groups. For instance, there are childhood diseases, diseases that typically affect young people (e.g., schizophrenia), and diseases associated with aging (e.g., osteoporosis). Aging gradually diminishes our physical and mental capabilities.

Factors related to human biology can be modified to some extent, while other factors are more amenable to change.

4.2) The Environment

Water, soil, air, and food can become contaminated, posing health risks. Increasing pollution contributes to higher morbidity and mortality rates. Waterborne and foodborne infections remain significant sources of disease.

Physical Contamination: Dust, smoke, radiation, noise, and solid and liquid waste are examples of physical contaminants.
Chemical Contamination: Heavy metals (lead, mercury, arsenic), sulfur and nitrogen oxides, pesticides, and food additives are examples of chemical contaminants.
Biological Pollution: Biological contamination originates from bacteria, viruses, fungi, protozoa, arthropods, pollen, and other biological agents.
Social Environment: Psychological, economic, and sociocultural factors can influence health. For example, stress can have a significant impact on health. The concentration of people in cities, the increased number and speed of vehicles, and the presence of various substances and equipment at home and work create new situations that can contribute to disease.

4.3) Lifestyle

Lifestyle choices are estimated to be responsible for 40% of preventable deaths.

Drug Use: Both legal drugs (tobacco, alcohol, certain medications) and illegal drugs can have detrimental effects on health. Smoking is the leading preventable cause of death in affluent societies. Morbidity and mortality from smoking are expected to rise as more women smoke and the age of initiation decreases. Alcohol consumption is also a significant risk factor in many societies, particularly where it is readily available and affordable. As with smoking, alcohol consumption is starting at a younger age.
Lack of Physical Activity: Physical inactivity contributes to osteoarthritis, atherosclerosis, and obesity, which in turn can exacerbate other diseases. A significant portion of the population leads a sedentary lifestyle, with limited engagement in regular physical exercise.
Nutrition: Some population groups experience deficiencies in essential nutrients, while others consume excessive amounts of fat, sugar, and protein, leading to health problems.
Violence: Violence manifests in various forms, including homicide, suicide, and accidents, all of which have significant health consequences.
Reckless Driving: Behaviors such as speeding, not wearing seatbelts or helmets, and driving under the influence of alcohol contribute to a large number of traffic fatalities each year.
Inappropriate Use of Healthcare: This includes delaying or avoiding seeking medical attention for health problems, not attending scheduled checkups, not adhering to prescribed treatments, and misusing medications.

Generally, individuals with higher socioeconomic status tend to have healthier habits, with the exception of smoking. Therefore, health education efforts should particularly target young people from lower socioeconomic backgrounds.

4.4) Healthcare System

Coverage or Access: Limited access to healthcare services can contribute to the onset or worsening of diseases.
Cost: The cost of healthcare can be a barrier to accessing necessary services, leading to a decline in health.
Quality: The quality of healthcare services, including their effectiveness, plays a crucial role in health outcomes. Recognizing the significant influence of lifestyle on health, many countries are strengthening their health policies to prioritize disease prevention and health promotion. However, a substantial portion of healthcare spending still focuses on treatment rather than prevention.

5) Health Inequalities

Health and socioeconomic development are closely intertwined. A certain level of income is necessary to acquire goods and services that contribute to well-being and health, such as adequate nutrition, housing, clothing, education, sanitation, and healthcare. However, a minimum level of health is also essential for individuals to generate income. This creates a vicious cycle where poverty and underdevelopment contribute to disease, and disease, in turn, perpetuates poverty and underdevelopment. This cycle is particularly evident in developing countries and among marginalized populations in developed countries.

In wealthy countries, the relationship between wealth and health is not linear. Beyond a certain threshold, increased wealth does not necessarily translate into better health. Health disparities exist not only between countries but also within countries, between cities, and even between neighborhoods.

Among impoverished populations, infectious diseases (especially gastrointestinal and respiratory infections affecting infants and children), nutritional deficiencies, and complications during pregnancy and childbirth are more prevalent.
Among affluent populations, infectious diseases are less common, and the leading causes of illness are related to lifestyle factors, environmental exposures, and aging.

Addressing health inequalities requires a multi-pronged approach. Impoverished populations need access to clean drinking water, sanitation, adequate nutrition, maternal and child healthcare, immunization programs, health education, and affordable medical care. In wealthy societies, efforts should focus on achieving sustainable development that is environmentally sound and benefits all members of society. It is also essential to improve the efficiency and effectiveness of healthcare spending.

6) Prevention

Prevention, a cornerstone of public health, is based on the principle that it is more effective to prevent disease than to treat it after it occurs. It aims to reduce the probability of disease onset and even enhance the overall health of the community. Prevention is a shared responsibility of all healthcare professionals.

Preventive measures encompass any actions taken to reduce the likelihood of developing a disease or condition, halting its progression, or at least slowing it down. Prevention can be implemented at various stages of the natural history of disease, including primary, secondary, and tertiary prevention.

6.1) Primary Prevention

Primary prevention focuses on eliminating or reducing the risk of developing a disease. It achieves this through several strategies, such as eliminating environmental pathogens, preventing contact between individuals and pathogens, and promoting healthy behaviors. Examples of primary prevention include sanitation measures, reducing exposure to radiation and irritants, promoting healthy lifestyle choices, and immunization programs.

6.2) Secondary Prevention

Secondary prevention aims to detect and treat diseases in their early stages, potentially halting or slowing their progression. This is particularly important for chronic diseases, which often have long asymptomatic periods. Early diagnosis involves screening for risk factors or the disease itself before clinical manifestations appear. This may involve physical examinations, laboratory tests, imaging studies, and other diagnostic procedures. While primary prevention is generally more effective for the overall health of the population, secondary prevention plays a crucial role in managing chronic diseases.

6.3) Tertiary Prevention

Tertiary prevention focuses on minimizing the impact of established diseases and preventing further complications or disability. Examples of tertiary prevention include health education for individuals with chronic conditions (e.g., diabetes), rehabilitation after a stroke or heart attack, and support for individuals with disabilities. Tertiary prevention emphasizes social rehabilitation, empowering patients to manage their conditions, and facilitating their reintegration into normal life and society. In industrialized societies, human behavior has become the primary determinant of health, making tertiary prevention increasingly important.