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, preventing disease, and prolonging life in the population through the organized efforts of society.” -- World Health Organization (WHO) science and art promoting health preventing disease prolonging lifein the population organized efforts of society

Functions of Public Health

Population Health Health Care Traditional Public Health Social Policy Population Health Hospitals Clinics Providers Insurers Researchers Etc. ACA Medicaid Taxation Smoking Guns Etc.

Career Areas Medicine Dentistry Health management Epidemiology Environmental health Health information Wellness Health policy Health inspection Social policy Research Health instruction Program planning Program evaluation Health assessment Community health

Public Health Competencies Discipline-SpecificCross-Cutting biostatisticscommunications and informatics environmental health sciencesdiversity and culture epidemiologyleadership health policy and managementpublic health biology social and behavioral sciencesprofessionalism 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 – Bacteria – Viruses – Protozoa (one-celled animals) – Fungi (plant-like) – Helminths (worm-like parasites) – Infectious proteins (e.g., mad-cow disease) Routes – 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 non- randomness.”

The Origin of Evidenced-based Public Health: Cholera in 19 th -Century London : 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”) : 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” What’s your interpretation of the evidence on this map? Black squares are cholera deaths The green circles are public water pumps.

Other Pumps (Lambeth and others) Broad Street Pump (Southwark & Vauxahall) Snow’s “Ghost Map”

John Snow’s Numerical Analysis Water Supplier# of Houses# of DeathsDeaths/10,000 Houses Southwark & Vauxhall40,0461, Lambeth26, Other256,4231,

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