Public health and population health during a pandemic. This module will provide an introduction to the structure and function of public health and population health. By the end of this module, you will be able to define and describe the role of public health in the United States, recognize the essential public health functions and their corresponding stakeholders, define population health and how it overlaps with and differs from public health, and identify the role of public health and population health during a pandemic. Charles-Edward Amory Winslow is a leading figure in the development of the modern study of public health. His definition of public health developed almost a century ago is as follows: "Public health is the science and art of preventing disease, prolonging life, and promoting health through the organized efforts and informed choices of society, organizations, public and private communities and individuals." Note the influences at the broader societal and community levels, as well as the individual levels. You will see examples of public health at each of these levels throughout this module. The National Academies of Health, formally called the Institute of Medicine, states that the mission of public health is fulfilling society's interest and assuring conditions in which people can be healthy. The National Academies is an American non-profit and non-governmental organization that provides unbiased, authoritative advice to decision-makers and the public. Similarly, the World Health Organization stresses that public health aims to provide maximum benefit for the largest number of people. The World Health Organization is an agency charged with spearheading international public health efforts. Public health focuses on groups of people rather than just an individual. At the core of public health lies the principle of social justice, providing people the right to be healthy and to live in conditions that will support their health. Now let's review the history of public health, and we will take a look at a few historical highlights through four lenses. The first lens we look through encompasses the control of disease and the promotion of health through sanitation to ensure a healthy environment. Here are three examples of how public health has worked to contain infectious disease through environmental measures. Around 500 BCE, the ancient Greeks and Romans actively practice community sanitation measures. Approximately two millennia later, the Public Health Act of 1848 was established. It provided a central board of health in placed responsibilities for sanitation in the hands of boroughs. In 1970, the Nixon Administration established the Environmental Protection Agency, which protects human health by safeguarding air, water and land. Next, we will explore pandemics. Pandemics are epidemics or outbreaks of disease that spread far and wide, affecting the populations of multiple continents. Influenza or the flu has caused pandemics and many times during both the distant past and recent history. Almost a century ago, the Spanish flu infected 500 million people across the world, including remote Pacific islands in the Arctic, killing 20-50 million persons. More recently, the influenza pandemic in 2009 infected persons in 214 countries causing almost 1,900 confirmed deaths. Preparing for and controlling the effects of influenza will remain likely a top priority for public health. Historically, polio was a common and a highly feared disease that cause severe illness, including paralysis and death among thousands of people each year. Thousands of people lined up to receive the polio vaccine after it was introduced in 1955. An initiative to eradicate polio was launched in 1988 because of outbreaks in more than 125 countries. Today, polio exists only in a few countries. The third area we'll explore is public health's role in preparedness and disaster response, both for natural disasters and human-made threats. The use of biological warfare to infect people and animals goes back centuries. During the Siege of Caffa in the 14th century AD, the attacking Tartar forces used plague as a weapon of war. By hurling plague-infected corpses into the enemy city, their actions started the first stage of black death or plague among Europeans. In the immediate wake of terrorist attacks on September 11th, 2001, public health workers were on the ground at the World Trade Center and the Pentagon conducting surveillance to identify outbreaks of diseases or other possible health conditions resulting from the attacks. Public health workers closely monitored the health of first responders, city residents and environmental conditions to detect health threats during the clean-up after the attack. The last lens we will look through as we view public health history is prevention and policy. Public health works to protect and improve health, not just by responding to disease outbreaks or preparing for natural or human-made disasters, but also by implementing policies that support these efforts on a societal level. As far back as 1500 BCE, Leviticus, the third book of the Hebrew Bible, is believed to be the first written health code in the world. The book deals with personal and community responsibilities, and includes guidance regarding bodily cleanliness, sexual health behaviors, protection against contagious diseases, and isolation of lepers. During 2000 and 2004, cigarette smoking was reported to be responsible for a $193 billion in annual health-related economic losses in the United States. Laws banning smoking in the workplace and other public places have been developed to encourage smokers to quit while protecting nonsmokers from the effects of secondhand smoke. Finally, more than one-third of US adults, approximately 17 percent of children and adolescents age 2-19 years of age are obese. Efforts to highlight fat, sugar, and salt content in foods throughout labeling regulations have been developed along with the promotion of physical activity in schools, workplaces, and neighborhoods. In New York City, the mayor and city council attempted to ban sodas larger than 16 ounces in an effort to combat the obesity epidemic. Now let's examine the framework for a public health approach. Let's talk about public health in a broader context. Public health problems are diverse, and can include infectious diseases, chronic diseases, emergencies, injuries, environmental health problems, as well as other health threats. Regardless of the topic, we take the same approach to a public health problem by following four general steps. First, we ask, what is the problem? In public health, we identify the problem by using surveillance systems to monitor the health of events and behaviors occurring among a population. After we've identified the problem, the next question is, what the cause of the problem? For example, are there factors that might make certain populations more susceptible to disease, such as something in the environment or certain behaviors that people are practicing? Once we've identified the risk factors related to the problem, we ask, what intervention works to address the problem? We look at what has worked in the past in addressing the same problem, and if a proposed intervention makes sense with our affected population. In the last step, we ask, how can we implement the intervention? Given the resources we have and what we know about the affected population, will this work? As we go through this module, you will see different examples of this public health approach at work. To implement the public health approach, practitioners use and apply scientific methods. These methods come from a series of core sciences that provide the foundation. These sciences include public health surveillance, which we use to monitor a public health situation, epidemiology, which enables us to determine where diseases originate, how or why they move through populations, and how we can prevent them. Public health laboratories support public health by performing tests to confirm disease diagnoses. Laboratories also support public health by conducting research and training. As we move from the use of paper documents to electronic records, and yes, there are still some paper documents in use, public health informatics continues to increase in importance. Informatics deals with the methods for collecting, compiling, and presenting health information. It enables us to use electronic data effectively when addressing a public health situation. Prevention effectiveness is closely linked to public health policy. Prevention effectiveness studies provide important economic information for decision makers to help them choose the best option available. Together, these five core sciences can help us protect and promote the public's health by giving public health practitioners the answers they need. Public health is better able to respond to the situation by using contributions from each of these sciences. One science alone cannot answer the questions and provide a solution, it is the application of these core sciences together. Let's look at how the public health approach can be applied to a historical example of infectious disease. During the 1800's in London, cholera, a fatal intestinal disease, was rampant, causing death to tens of thousands of people within hours of the first symptoms. At the time, which was before bacteria and viruses were recognized as the cause for many diseases, popular opinion held that cholera was caused by bad air coming from rotting organic matter. John Snow, a British physician during that time, had a different opinion of cholera. He believed that the illness was spreading by way of contaminated water supply because sewage was routinely dumped into the Thames River and cesspools near town wells. Because of his work tracing the source of cholera outbreak, he is often considered the father of modern epidemiology. His research changed the way we look at disease. The red circle depicts the neighborhood in question and the black dots represent the deaths from cholera. Notice the higher density of deaths around Broad Street. Snow was assisted by a local clergyman, Reverend Henry Whitehead, in tracking down, interviewing cholera victims and their families in geographically mapping the outbreak. Their efforts highlight the benefits of linking scientific inquiry with engagements of community stakeholders and shared ownership for health. Next, he examined the data and tried to identify risk factors. That is, he tried to determine the cause of the deaths by using the pattern of where cases were occurring. This slide illustrates the location of the water pumps which are indicated as black boxes. On the basis of his previous works, Snow believed that water was a potential cholera source. Using the final step of the public health approach, Snow implemented the intervention by removing the handle from the Broad Street pump so that no one could continue to draw water from the contaminated water supply. After a long battle with politicians and water companies, he finally convinced the British government that water contaminated with sewage was the source of cholera and other diseases which resulted in the implementation of policies and laws for water sanitation. Now, let's look at the core functions and services of public health. Ten essential public health services are grouped under three core functions. These services are not a prescription for what public health agency should be doing. Instead, they are intended to serve as a descriptive tool to capture the field of public health and to communicate what public health provides. Now, let's think about how these essential services can be implemented and we'll use COVID-19 as an example. Assessment, monitoring health status. An example is monitoring the prevalence of COVID -19 symptoms among the general public. Diagnosing and investigating health problems. This is applied by investigating risk factors associated with COVId-19. Next, we move to policy development. In this area, we inform, educate, and empower people about health concerns and plays public service announcements on television regarding the signs and symptoms of coronavirus. In mobilizing community partnerships, we work with advocacy groups to educate communities about ways to prevent the spread of COVID. Developing policies and plans, an example is the CDC, which has developed a series of specific guidelines regarding diagnostic testing and plans to mitigate the spread of the disease. In the last area is assurance, enforcing laws and regulations and policies such as social distancing, isolation and quarantines have been used again to mitigate the spread of the disease. Linking people to needed personal health services addresses potential barriers related to the availability of diagnostic testing and treatment for COVID. Assuring a competent public health and personal health care workforce is critical and ensuring that a knowledgeable workforce conducts testing and contact tracing. Then moving to evaluate the effectiveness of information that's provided and of clinical services. Lastly, research for new and innovative solutions to health programs, taking insights gained from the field on what works and to confirm them through collaborative study with health researchers. Together, these form the 10 essential public health services. The field of public health is broad and interdisciplinary. Beyond government, it requires stakeholders with skills and intervention programs, policies, research, evaluation, and education. Think about what other sectors and fields that have a stake in public health. Some possible answers might be transportation, housing, schools, city planning, or law enforcement. Here are some of the other primary partners in public health. Increasingly, social media serves as a vehicle for the public discourse on public health concerns and historically, public health agencies and other partners have educated the public and promoted healthy behaviors through the news and entertainment media. Employers and businesses contribute to the public's health by providing health insurance for example, workplaces also have wellness initiatives such as gym subsidies that promote the health of their employees. Government agencies such as CDC work in partnership with state, local, and tribal health departments. However, important contributions are made by other government agencies at all levels. City planning departments can include sidewalks and bike paths to promote and support safe ways to exercise. Education departments can include public health messages for students, implement prevention and school health programs and work to ensure healthy food options at schools. Similarly, many other government agencies can work as partners in public health by including health considerations in their policy development. Academia educates and trains the public health workforce such as scientists, epidemiologists, and informaticians. Additionally, research conducted in academia is put to use in the larger communities around the US and the world. Utilizing the public health approach discussed earlier, numerous achievements have been experienced in the United States. Some of these achievements include: vaccinations that have reduced disease and even eliminated others such as smallpox, safer workplaces with regular safety inspections, safer and healthier food supply with regulations and inspections of restaurants and plants, motor vehicle safety laws, fluoridated drinking water that reduces dental caries and improves oral health, family planning that results in healthier moms and babies, declines in tobacco smoking, which in part lead to reductions in death from heart disease and stroke, and control of infectious disease are just a few examples. Given the current pandemic, you might wonder why control of infectious diseases is listed as an achievement. Remember our earlier discussion of the myriad of communicable diseases that devastated populations in the past. The development of vaccines and the effective treatments for influenza and HIV have decreased morbidity and mortality worldwide. There is currently a worldwide effort to develop treatments that are effective, available and affordable, including vaccines for COVID-19. Now let's take a brief look at the emerging field of population health. Health is a complete state of physical, mental, and social well-being and not merely the absence of disease or infirmity. That is the definition from the World Health Organization. Public health is what we as a society do collectively to assure the conditions in which people can be healthy. Population health is a systems framework for studying and improving the health of populations through collective action and learning. The essential goals include: protecting and promoting health inequality, transforming people and place, creating a healthy planet, and achieving health equity. Public health and population health are related areas that both consider the health of the public. Public health focuses on the population's health as a whole, while population health tends to focus on particular population groups, such as specific clinical or geographic populations. Public health seeks to explore prevention strategies and identify causes of problems that affect the larger populations, whereas population health keenly focuses on reducing health inequalities among and between population groups. According to Keyes and Galea, population health science is an emerging discipline at the crossroads of demography, sociology, epidemiology, health science, and economics that provides a comprehensive framework for systems thinking to allow how traditional health sciences measures and observe health events. The current COVID-19 pandemic underscores the salience of this field as experts draw upon each of these foundational fields to describe the populations most affected, factors that predispose vulnerable groups, the financial impact of COVID-19, and ultimately the development of potential strategies to mitigate the disease. Several population groups have shown particular vulnerability to Coronavirus. These groups include the elderly, those with underlying health conditions, and communities of color. The module on health equity explores these topics in detail. But these suggested readings present opportunities to reinforce your knowledge about populations at high risk for COVID-19. Public health and population health utilize complimentary tactics to address the current pandemic. Public health seeks to prevent disease among those who are not yet sick. These tactics have been critical during the COVID-19 pandemic, particularly since we do not yet have a vaccine: Isolation for those who are ill, quarantines to those who may have been exposed, social distancing to mitigate the spread, hand washing for prevention and testing, and contact tracing to identify disease and potential cases. Population health seeks to prevent and manage disease among particular vulnerable groups by identifying and addressing social factors that plays populations at risk, such as food insecurity, personal safety, and housing. It conducts passive and active surveillance of health disparities, continued attention to chronic diseases such as hypertension and diabetes that predispose at-risk populations, and highlighting the range of inequalities that need to be addressed throughout interventions. In closing, public health is the science of protecting and improving the health of people and their communities. Assessment; collecting and analyzing community data, policy; the use of scientific knowledge to inform policy decisions, and assurance; provision of necessary services are three core public health functions. Population health seeks to improve the health outcomes of entire populations through collaborations to improve health and health equity, transform communities, and create a healthy planet. Population health also helps us to understand the spread of COVID-19, its community impact, and its disproportionate effect on vulnerable populations. We hope this brief introduction to the important fields of public health and population health will pique your interest to learn more, particularly as you work as a contact tracer. Thank you for your attention.
