Public health in the United States has evolved significantly over the centuries, shaped by various social, economic, and scientific developments.
Early beginnings
This book applied epidemiological principles and identified specific health hazards, such as exposure to chemicals, dust, and metals, as well as musculoskeletal injuries from unnatural postures and repetitive or violent motions.
1700Public health efforts began with quarantine measures to control infectious diseases like smallpox and yellow fever.
Lemuel Shattuck (1793–1859), developed a statewide registration program of vital statistics in Boston MA, which later became a model elsewhere in the USA.
The Shattuck Report in Massachusetts (1850) promoted the concept of municipal boards of health based on public health law with a public mandate to supervise and regulate community sanitation. This included urban planning, zoning, restriction of animals and industry in residential areas, and regulation of working conditions, setting the basis of public health infrastructure in the United States.
Colonial EraThe establishment of the Marine Hospital Service in 1798 marked the federal government’s first major public health initiative, focusing on the health of seamen.
This later became the US Public Health Service. The American Public Health Association (APHA) was founded in 1872 as a professional educational and lobbying group to promote the interests of public health.
19th CenturyMajor milestones
In the mid-1800s, the sanitation movement, led by figures like John Snow and Edwin Chadwick, emphasized the importance of clean water and waste disposal to prevent disease. John Snow (1813–1858) hypothesized the cholera epidemics occurring in London between 1848 and 1854 were caused by the contaminated water from the River Thames distributed to homes in a large area of south London. The risk to local residents of becoming infected and falling ill with cholera was dependent upon the specific water company as well as the pump utilized. He persuaded authorities to remove the handle of the Broad Street and the epidemic disappeared within a few days.
Edwin Chadwick (1800–1900) was a leader of the social reform movement in England. He authored the report “The Sanitary Conditions of the Labouring Population” (1842), which used quantitative methods to show a direct link between poor living conditions and disease and life expectancy. This report inspired major efforts by local authorities to improve sanitation and led to parliamentary adoption of the Public Health Act of 1848, establishing a General Board of Health that focused on the safety of community water supplies and drainage, establishing municipal boards of health in the major cities, and rural local authorities and housing legislation, as well as other societal reforms.
The acceptance of germ theory in the late 19th century revolutionized public health by identifying microorganisms as the cause of many diseases. Previously, the miasma theory, dating to Greek and Roman medicine, posited disease was the result of environmental miasmas, which were infectious mists and noxious vapors emanating from filth in the towns. The way to prevent infectious diseases was to establish sanitary measures to clean the streets of garbage, sewage, animal carcasses, and wastes. Snow’s work, as well as that of others, such as Peter Panum’s study of the measles outbreak in the Faroe Islands in 1846, provided credibility to the germ theory. Note: The sanitary movement nevertheless represents an important element of public health efforts.
Louis Pasteur (1822–1895), a French professor of chemistry, proved the germ theory of disease and invented the process of pasteurization. Edward Jenner (1749–1823) uses variolation of pustular material from cowpox to vaccinate against smallpox in 1796. Pasteur’s work on attenuation—i.e., weakening an organism’s strength by passing it successively through animals, recovering it, and retransmitting it to other animals—was foundational to the development of vaccines and further supported the germ theory.
Robert Koch (1843–1910) cultured and demonstrated the tubercle bacillus in 1882. “Koch’s postulates,” criteria for disease causation, substantiated the germ theory, for which he was awarded the Nobel Prize in Physiology or Medicine in 1905.
20th-century developments
The development and widespread use of vaccines significantly reduced the incidence of diseases like polio, measles, and smallpox.
In 1952, there were more than 52,000 cases of poliomyelitis reported in the United States. Physician and epidemiologist Jonas Salk (1914–1995) developed the first inactivated vaccine (IPV). In 1954, Salk successfully completed the largest field trial ever performed, which involved almost 2 million children. Albert Sabin (1906–1994) developed a live, attenuated vaccine given orally (OPV), which was approved by the FDA in 1961.
The establishment of organizations like the Centers for Disease Control and Prevention (CDC) in 1946 provided a coordinated approach to disease prevention and health promotion. The Environmental Protection Agency was founded in 1970 to protect human health and the environment.
Modern Public Health
Chronic diseases
The focus has shifted from infectious diseases to chronic diseases, such as heart disease, diabetes, and cancer. Obesity, diabetes, heart disease, and cancer are among the leading causes of morbidity and mortality.
Health Disparities
Addressing social determinants of health and reducing health disparities have become central goals of public health efforts.
Schism of Public Health and clinical practice in the early 1900s
The early 20th century saw a growing divide between public health and clinical practice, driven by several factors:
Public Health training: Public health education was often separate, with its own schools and curricula, emphasizing population health and preventive measures.
Different priorities: Clinicians prioritized patient care and treatment, while public health professionals focused on prevention, health promotion and the health of populations.
Resource allocation: Limited resources led to competition between clinical and public health sectors, further widening the gap.
Separate institutions: Public health departments and medical schools operated independently, with little collaboration or integration.
Policy and practice: Public health policies were often developed without input from clinicians, leading to a lack of coordination in health initiatives.
Role of the Flexner Report
The Flexner Report, published in 1910, played a pivotal role in shaping medical education and had significant implications for public health.
Commissioned by the Carnegie Foundation, Abraham Flexner evaluated the state of medical education in the United States and Canada. The report highlighted the poor quality and inconsistency of medical education, calling for major reforms.
Recommendations
- Higher standards: The report recommended higher admission and graduation standards, emphasizing scientific rigor and clinical training.
- Reduction of medical schools: Flexner suggested reducing the number of medical schools to improve quality and ensure adequate resources.
Impact on Public Health
- Integration challenges: While the report improved medical education, it also reinforced the separation between clinical practice and public health by focusing on clinical training.
- Public Health education: The emphasis on clinical skills led to a decline in public health education within medical schools, contributing to the schism between the two fields.
Long-term effects
- Professionalization: The report professionalized medical education, leading to better-trained physicians but also creating barriers to integrating public health principles into clinical practice.
- Legacy: The Flexner Report’s legacy continues to influence medical education and the relationship between public health and clinical practice today.