Public Health History PDF

TOPIC 1 Pre-historic times Health practices tied to religious or spiritual beliefs. Shamanism- shamans/medicine men as natural healers Geophagy- ingestion of clay or earth Trepanation- drilling a hole into the human skull Classical Culture (500 B.C.E.–500 C. E.) Hippocrates- “Father of Medicin...

TOPIC 1 Pre-historic times Health practices tied to religious or spiritual beliefs. Shamanism- shamans/medicine men as natural healers Geophagy- ingestion of clay or earth Trepanation- drilling a hole into the human skull Classical Culture (500 B.C.E.–500 C. E.) Hippocrates- “Father of Medicine”and contributed largely to the “professionalization” of medicine. “De Aere, Aquis Et Locis”- “Of Air, Water, and Land”; states that diseases develop because of our environment and not because of of divine act. Greeks were involved in practice of community sanitation. Romans were community minded; improved on community sanitation of Greeks; built aqueducts to transport water from miles away; built sewer systems; created regulation for building construction, refuse removal, and street cleaning and repair; created hospitals as infirmaries for slaves. Christians created hospitals as benevolent charitable organizations. 476 c. e. : Roman Empire fell and most public health activities ceased. Middle Ages (500–1500 C. E.) 500–1000c.e. (Dark Ages): Growing revulsion for Roman materialism and a growth of spirituality; health problems were considered to have both spiritual causes and spiritual solutions, a time referred to as the spiritual era of public health Deadliest epidemics were from plague (“Black Death”) also known as the Bubonic Plague, caused by a bacteria Yersinia pestis, transmitted through flea bites. Syphilis epidemic was last epidemic of the period Renaissance and Exploration (1500–1700 C. E.) Belief that disease was caused by environmental, not spiritual, factors; for example, the term malaria, meaning bad air, is a direct reference to humid or swampy air. Observation of ill led to more accurate descriptions of symptoms and outcomes of diseases; observations led to first recognition of whooping cough, typhus, scarlet fever, and malaria as distinct and separate diseases. 1662: John Graunt published the Observations on the Bills of Mortality, which was the beginning of vital statistics. Explorers, conquerors, and merchants and their crews spread disease to colonists and indigenous people throughout the New World. 18th Century: Industrial growth led to poor sanitation, overcrowding, and unsafe workplaces. 1796: Edward Jenner developed the smallpox vaccine. 19th Century: 1854: John Snow linked cholera to contaminated water, disproving miasma theory. 1862: Louis Pasteur proposed germ theory, ending belief in spontaneous generation. 1875–1900: Known as the bacteriological period. Role of Florence Nightingale in sanitation and nursing (Crimean War, 1853–1856). Modern era of public health - the era of public health that began in 1850 and continues today. In the Philippines, the American colonizers established “Board of Health for the Philippine Islands” and eventually became the “Department of Health”. The first secretary was Dr. Jose Fabella. After World War II, World Health Organization (WHO) was established in 1948. Two years earlier, the Center for Disease Control and prevention (CDC) was established in Atlanta, USA. HEALTH Origin: Hal (hale, sound, whole). Health a dynamic state or condition of the human organism that is multidimensional in nature, a resource for living, and results from a person’s interactions with and adaptations to his or her environment; therefore, it can exist in varying degrees and is specific to each individual and his or her situation. WHO Definition (1946): “health is a state of complete physical, mental, and social well-being and not merely the absence of disease and infirmity.” Determinants of Health (a) Gestational Endowments (b) Social Circumstances (c) Environmental Conditions (d) Behavioral Choices (e) Medical Care COMMUNITY Traditionally, a community has been thought of as a geographic area with specific boundaries. In the context of public health, community is “a collective body of individuals identified by common characteristics such as geography, interests, experiences, concerns, or values.” Characterized by the elements: 1. membership 2. common symbol system 3. shared values and norms 4. mutual influence 5. shared needs and commitment to meeting them 6. shared emotional connection Public, Community, Population, and Global Health Public health- actions that society takes collectively to ensure that the conditions in which people can be healthy Public health system- the organizational mechanism of those activities undertaken within the formal structure of government and the associated efforts of private and voluntary organizations and individuals Community health- the health status of a defined group of people and the actions and conditions to promote, protect, and preserve their health Population health- the health outcomes of a group of individuals, including the distribution of such outcomes within the group Global health- describes health problems, issues, and concerns that transcend national boundaries, may be influenced by circumstances or experiences in other countries, and are best addressed by cooperative actions and solutions Personal Health Activities - Personal health activities are individual actions and decision-making that affect the health of an individual or his or her immediate family members or friends. e.g. choosing to eat wisely, to regularly wear a safety belt, and to visit the physician Community and Public Health Activities - Community and public health activities are activities that are aimed at protecting or improving the health of a population or community. e.g. maintenance of accurate birth and death records, protection of the food and water supply, etc. FACTORS THAT AFFECT THE HEALTH OF THE COMMUNITY Social and Cultural Factors Individual behaviors Community Organization Physical Factors Physical Factors Geography: Influence of climate and location on diseases. Environment: Natural and built environments (e.g., urban design, transportation). Community size: Resources and challenges (e.g., disease spread, waste management). Industrial development: Positive (resources) and negative (pollution, occupational injuries) effects on health status of the community. Social and Cultural Factors Social factors are those that arise from the interaction of individuals or groups within the community. Cultural factors arise from guidelines (both explicit and implicit) that individuals “inherit” from being a part of a particular society. -Beliefs, traditions, and prejudices. -Social norms (e.g., changes in smoking and alcohol consumption) -Socioeconomic status: Strong correlation with health disparities. -Politics -Religion Community Organizing -Is “the process by which community groups are helped to identify common problems or change targets, mobilize resources, and develop and implement strategies for reaching their collective goals.” -It is not a science but an art of building consensus within a democratic process. Individual Behavior -The behavior of the individual community members contributes to the health of the entire community. It takes the concerted effort of many—if not most—of the individuals in a community to make a program work. e.g. the more individuals who become immunized against a specific communicable disease, the slower the disease will spread and the fewer people will be exposed. This concept is known as herd immunity. Community Health Is a subset of Public Health. Charles-Edward Amory Winslow (1920) – Father of Public Health – “the science and art of preventing disease, prolonging life, and promoting physical health and efficiency through organized community efforts for the sanitation. Community Health Core Elements (MacQueen et al., 2001) 1. Locus: Geographical place or boundary. 2. Sharing: An existence of “shared perspectives” and “common interest” 3. Joint action: “source of community cohesion and identity” 4. Social ties: “Interpersonal relationships” (e.g., family, peers). 5. Diversity: “Communities within a community” Roles of Health Organizations World Health Organization (WHO) Sets global health standards, coordinates international health responses, develops public health guidelines, and manages health emergencies (e.g., pandemics). United Nations Children’s Fund (UNICEF) Focuses on child health and nutrition, vaccination programs, maternal health, and advocacy for child rights. International Red Cross and Red Crescent Movement Provides disaster relief, health services in conflict zones, blood donation campaigns, and training for first responders. Global Fund to Fight AIDS, Tuberculosis, and Malaria Finances initiatives to reduce the impact of these diseases in low-income regions through treatment and prevention programs. Centers for Disease Control and Prevention (CDC) Offers technical expertise and training to combat global infectious diseases and strengthen public health capacity. TOPIC 2 : HUMAN ECOLOGY & DEMOGRAPHY ECOLOGY From the Greek oikos (οἶκος) meaning ‘household,’ or ‘place to live’ The scientific study of the distribution and abundance of living organisms and the interactions among organisms and between the organisms and their environment. Environment of an organism includes: 1. Physical properties which can be described as the sum of local abiotic factors a. insolation (sunlight) b. climate c. geology 2. Biotic factors which are other organisms that share its habitat HUMAN ECOLOGY - A term introduced by sociologists Burgess and Park in 1921. - Explores not only the influence of humans on their environment but also the influence of the environment on human behavior, and their adaptive strategies as they come to understand those influences better. - Interdisciplinary applied field that uses a holistic approach to help people solve problems and enhance human potential within their near environments. DEMOGRAPHY - The statistical study of all populations. - It encompasses the study of the size, structure and distribution of populations, and spatial and/or temporal changes in them in response to: a. birth b. death c. migration d. aging DEMOGRAPHY Important concepts in demography: 1. Crude birth rate – the annual number of live births per 1000 people Formula: (No. of live births per year /Total population) x 1000 2. General fertility rate – the annual number of live births per 1000 women of child bearing age (15 – 49 years old). Formula: (No. of live births per year/ Total female population (15 – 49 years old)) x 1000 3. Age-specific fertility rate – is the number of resident live births to women in a specific age group for a specified geographic area (country, state, county, etc.), divided by the total population of women in the same age group for the same geographic area (for a specified time period, usually a calendar year). Formula: (Number of Resident Live Births to Women in a Specific Age Group / Number of Women in the same Age Group) x 1000 4. Crude death rate – annual number of deaths per 1000 people. Formula: (Number of annual deaths / Total population) x 1000 5. Infant mortality rate – annual number of deaths of children less than 1 year old per 100,000 live births. Formula: (No. of Annual death of infants (less than 1 year old)/No. of live births) x 100,000 6. Expectation of life (Life expectancy) – Number of years a person is expected to live from a specified starting point. 7. Total fertility rate – number of live births per woman completing her reproductive life  Formula: [∑(age specific fertility rates)] * (age interval of women) / 1,000 8. Gross reproduction rate – number of daughters who would be born to a woman completing her reproductive life at current age-specific fertility rates. 9. Net reproduction ratio – is the expected number of daughters, per newborn prospective mother, who may or may not survive to and through the ages of child bearing. 10. Case fatality rate – is the percentage of cases that result in death. It measures the severity of the disease and is proportionate to the virulence of a disease agent. (No. of deaths from a particular disease in a specific period of time / No. of cases of that same disease in the same time period) x 100 TERMS Population – collection of people or organisms of a particular species living in a given geographic area or mortality or migration. Survey – a method of gathering any type of information or data from a sample of individuals. It is meant that the data is only taken from a portion of the total population under study. Census – it is the counting of data gathered from the entire population. It is regularly occurring and official count of the human population of a certain local administrative unit. In the Philippines, the agency that conducts the census is the National Statistics Office. Processes that Affect Population Change: 1. Fertility 2. Mortality 3. Migration Population growth – the increase in a region’s population Biotic potential – the maximum reproductive capacity of a population under optimum environmental conditions. - Inherent power of organisms to reproduce and survive. (Chapman) Population control – The practice of curtailing population increase, usually by reducing the birth rate. NOTIFIABLE DISEASES - Diseases for which health officials request or require reporting for public health reasons - Part of a system called “epidemiological surveillance”, used by governments to recognize that an epidemic is occurring before people start dying. - These are usually infectious diseases whose spread can be prevented if the appropriate actions. are taken. - The timely reporting of cases of notifiable diseases allows public health authorities to detect an emerging epidemic at an early stage. NOTIFIABLE DISEASES: DOH (2022) REPUBLIC ACT No. 11332 An Act Providing Policies and Prescribing Procedures on Surveillance and Response to Notifiable Diseases, Epidemics, and Health Events of Public Health Concern, and Appropriating Funds Therefor, Repealing for the Purpose Act No. 3573, Otherwise Known as the "Law on Reporting of Communicable Diseases” Approved: April 26, 2019. Revised: 2020 CATEGORY I Acute Flaccid Paralysis Adverse Event Following Immunization Anthrax COVID-19 Hand-Foot-and-Mouth Disease Human Avian Influenza Measles Meningococcal Disease Middle East Respiratory Syndrome (MERS) Neonatal Tetanus Paralytic Shellfish Poisoning Rabies Severe Acute Respiratory Syndrome (SARS) CATEGORY II Acute Bloody Diarrhea Acute Encephalitis Syndrome Acute Hemorrhagic Fever Syndrome Acute Viral Hepatitis Bacterial Meningitis Cholera Dengue Diphtheria Influenza-like illness Leptospirosis Malaria Non-neonatal Tetanus Pertussis Typhoid and Paratyphoid Fever [ ] : EPIDEMIOLOGY EPIDEMIOLOGY Derived from the Greek words “epi” (on, upon), “demos” (people), and “logos” (study). Can be literally translated into the phrase “the study of that which is upon the people” The goal of epidemiology is to limit undesirable health events in a community. DEFINITIONS 1. American Society of Epidemiology: – The science or knowledge of the natural history of disease. 2. Frost (1931): – The science of the mass-phenomenon of infectious diseases, or as the natural history of infectious diseases; concerned not merely with describing the distribution of disease, but equally or more fitting into a consistent philosophy. 3. Stallybrass (1931): – The science of the infective diseases, their prime causes, propagation and prevention. 4. MacMahon:  – The study of the distribution and determinants of disease frequency in man. 5. Leavell and Clark: – A field of science which is concerned with the various factors and conditions that determine the occurrence and distribution of health, disease, defect, disability and death among group of individuals. 6. Oxford University Press: - the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to control health problems 7. Lilienfield (1976): – The study of the distribution of a disease or physiologic condition in human populations and of the factors that influence this distribution. Components: Human population Factors Agent EPIDEMIOLOGIST - “an investigator who studies the occurrence of disease or other health- related conditions or events in defined populations.” - Epidemiologists look for common exposures or other shared characteristics in the people who are sick, seeking the causative factor. HISTORY - it is possible to trace the roots of epidemiological thinking back to the “Father of Medicine,” Hippocrates, - Hippocrates (in 300 B.C.E.) suggested a relationship between the occurrence of disease and the physical environment - But the first example of the use of epidemiology to study and control a disease occurred in London between 1853 and 1854 - John Snow: The Father of Modern Epidemiology Early applications were largely dominated by infectious disease. It was born with the great epidemics that attracted first serious efforts to explain the occurrence of these diseases. Examples: 1. Great plague/bubonic plague in Europe and Asia 2. Yellow fever epidemic (New World, 1793 - 1803) studied by Dr. Benjamin Rush and later, Major Walter Reed 3. Cholera epidemic in London as investigated by John Snow 4. Typhoid fever as studied by William Budd HISTORY: NOTABLE FIGURES Hippocrates The father of medicine, also recognized the influence of environment and expressed his idea that diseases may be connected with person’s environment. Fracastorious (Girolamo Fracastoro) Italian doctor and poet, used epidemiologic method of reasoning expressed in his book (De Res Contagiosa) and stated that disease results from specific contagious or seeds of disease. John Graunt (1620-1674) Famous for his uses of statistics specifically his notes on high IMR, excess deaths of males over females. He was believed to have made the first life table. Farr (1807-1883) Also noted for his work on statistics notably mortality among Cornish metal workers, prisoners, married-unmarried, organized first vital statistical systems. From the 1950’s epidemiology has been applied to chronic disease and other conditions. examples: smoking and lung cancer, etc. OBJECTIVES OF EPIDEMIOLOGY 1. To identify the etiology or the cause of a disease and the risk factors - factors that increase the person’s risk for a disease. 2. To determine the extent of disease found in the community. 3. To study the natural history and prognosis of the disease. 4. To evaluate new preventive and therapeutic measures and new modes of health care delivery. 5. To provide the foundation for developing public policy and regulatory decision relating to environmental problems. AIMS OF EPIDEMIOLOGY 1. Prevention of disease 2. Maintenance of health 3. Promotion of health EPIDEMIOLOGICAL TERMS 1. Disease – any harmful deviation from the normal structural or functional state of an organism, generally associated with certain signs and symptoms and differing in nature from physical injury 2. Health outcome – refer to the health consequences brought about by the treatment of a health condition or as a result of an interaction with the healthcare system 3. Frequency - refers not only to the number of health events, but also to the relationship of that number to the size of the population 4. Pattern - refers to the occurrence of health-related events by time, place, and person 5. Incidence rate - sense of the speed with which disease occurs in a population, and seems to imply that this pattern has occurred and will continue to occur for the foreseeable future. 6. Prevalence rate – proportion of the population that has a health condition at a point in time 7. Case fatality rate – the proportion of persons with the disease who die from it 8. Mortality rate – a measure of the frequency of occurrence of death in a defined population during a specified interval 9. Crude rates – are those in which the denominator includes the total population; relatively easy to obtain and are useful when comparing similar populations 10. Age-adjusted rates – used to show what the level of mortality would be if the age composition of different populations were the same. A way of comparing two groups that differ in some important variable (e.g., age) by mathematically eliminating the effect of that variable EPIDEMIOLOGICAL COMPONENTS 1. Human population 2. Distribution 2.1. Epidemic – occurrence in a community of cases in excess of normal expectancy; “outbreak” 2.2. Endemic – constant or habitual presence of a disease/agent in a given place 2.3 Pandemic – epidemic of worldwide proportion 2.4 Sporadic – few, unrelated cases in several areas 3. Factors 3.1 Agent 3.2 Host 3.3 Environment AGENT-RELATED PROPERTIES Properties which relate to its perpetuation as a species: 1. Viability 2. Growth requirements 3. Host range 4. Evolution of drug-resistant strains HOST-RELATED PROPERTIES 1. Infectivity – ability to infect 2. Pathogenicity – ability to cause disease a. rapidity and extent of multiplication b. tissue damage c. elaboration of toxin 3. Virulence – severity of the disease that occurs 4. Immunogenicity – ability to induce specific immunity in the host a. amount of antigen in the host b. site of multiplication c. extent of dissemination MODELS OF DISEASE CAUSATION A. The Epidemiologic Triad / The Epidemiologic Triangle It implies that each of the three (3) factors must be analyzed and understood for comprehension and predictions of patterns of a disease. [ ] B. The Lever The interaction of agent, host and environment is compared to a lever balanced over a fulcrum. [ ] C. The Wheel The model consists of a hub (host or human) which has genetic make-up as its core. Surrounding the host is the environment, schematically divided into three sectors - biological, social and physical. [ ] D. The Web of Causation The essence of the concept is that effects never depend on a single isolated cause, but rather develop as the result of chains of causation at which each link itself is the result of a “complex genealogy of antecedents”. [ ] KINDS OF EPIDEMIOLOGIC STUDIES 1. Descriptive Studies - seek to describe the extent of disease in regard to person, time, and place. These studies are designed to answer the questions who, when, and where. 2. Analytic Studies - The purpose of analytic studies is to test hypotheses about relationships between health problems and possible risk factors, factors that increase the probability of disease.