Transcript GEN-101 20130930 - University of Louisville Public

GEN-101: Public Health
Pete Walton, M.D.
Associate Dean for Academic Affairs
School of Public Health and Information Sciences
What is Public Health?
“Public health is the science and art of
promoting health
health, preventing disease
disease, and
prolonging life in the population through the
organized efforts of society
society.”
-- World Health Organization (WHO)
Functions of Public Health
Population Health
Population Health
Health Care
Hospitals
Clinics
Providers
Insurers
Researchers
Etc.
Traditional
Public Health
Social Policy
ACA
Medicaid
Taxation
Smoking
Guns
Etc.
Career Areas
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Medicine
Dentistry
Health management
Epidemiology
Environmental health
Health information
Wellness
Health policy
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Health inspection
Social policy
Research
Health instruction
Program planning
Program evaluation
Health assessment
Community health
Public Health Competencies
Discipline-Specific
Cross-Cutting
biostatistics
communications and informatics
environmental health sciences
diversity and culture
epidemiology
leadership
health policy and management
public health biology
social and behavioral sciences
professionalism
program planning
systems thinking (critical thinking)
How Do We “Measure” Disease
• Morbidity – being sick
– Prevalence – proportion of people who are sick at
a given point in time
– Incidence – proportion of people who get sick
during a given period of time
• Mortality – deceased
– Mortality rate – proportion of people who die
during a given period of time
How Do People Get Infections?
• Agents
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Bacteria
Viruses
Protozoa (one-celled animals)
Fungi (plant-like)
Helminths (worm-like parasites)
Infectious proteins (e.g., mad-cow disease)
• Routes
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Inhaled – droplets, cysts & spores
Contact – direct, indirect
Ingested – food, water & other liquids & solids
Through skin – bites, needles, wounds & cuts
Key Assumption of Evidence-Based
Population Health
“The underlying theory of population health is
that the distribution of health and disease in
the population is not random and that we
can identify the reasons for the nonrandomness.”
The Origin of Evidenced-based Public Health:
Cholera in 19th-Century London
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1831-1832:
 first modern outbreak in Britain
 23,000 deaths
 helped to launch the sanitary reform movement, which was
based on miasma theory of disease (“bad smells”)
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1848-1849:
 250,000 cases and 53,000 deaths
 prompted Snow (and others) to investigate causes based on
contagion theory of disease (“person-to-person spread”)
Snow’s “Ghost Map”
Black squares are
cholera deaths
The green
circles
are
public water
pumps.
What’s your interpretation of the evidence on this map?
Snow’s “Ghost Map”
Broad Street
Pump (Southwark
& Vauxahall)
Other Pumps (Lambeth and others)
John Snow’s Numerical Analysis
Water Supplier
# of Houses
# of Deaths
Deaths/10,000 Houses
Southwark & Vauxhall
40,046
1,263
315
315
Lambeth
26,107
98
38
256,423
1,422
56
Other
What Really Happened
• Removal of the Broad Street pump handle by Snow,
thereby stopping the epidemic, is legend and NOT based on
historical evidence.
– He persuaded the public authorities to remove it (grudgingly),
and it was removed after the epidemic had already peaked.
• It took Snow years to convince the authorities that water
was the problem, not smelly air, and to force the water
company to change where it drew water from the Thames,
– Which was right downstream from the outlet from one of the
sewers built to eliminate miasma!
• Snow died in 1858; the cholera bacterium was not
discovered until 1884 and proven by Koch to cause cholera.
Questions