ANT C68 Lecture 2.doc

ANTC68 Lecture 2: Jan 17, 2013 Epidemiology What do I have to know from the readings? • Pay special attention to anything covered in lecture or in multiple readings. • Don’t worry about formulas or definitions or minute details unless they are in the lecture material. • Material that is emphasized in the readings (ie concepts spanning multiple paragraphs/pages) is examinable even if it’s not in the lecture. Example: Sattenspiel 2000a, section on diabetes • Remember you can always use examples from the readings to support your written answers If you are planning to write an essay for this class, submit a paper with your name, student number and potential topic to me NEXT WEEK. Potential topics: anything covered in this course or using an anthro approach to epidemics. You CANNOT write on the current influenza epidemic (the other class is doing that and the expectations are different). History: Hippocrates • A Greek physician, the “Father of Medicine” • Adhered to the principles of OBSERVATION in medicine • Believed in HUMORAL theory • Disease comes from an IMBALANCE in nature (anything that upsets the humors) - holistic • Thought that LOCATION was very important in determining disease outcomes • Recognized seasonality of epidemics and treatments • Also believed in MIASMA (bad air) as a cause of disease • Medical doctors today still take the Hippocratic Oath (‘Do no harm’) > Malaria – Galen = Greek practicing in Rome. Recognized swamps unhealthy places History: Anton van Leeuwenhoek (1632-1723) -> Good to know dates for exam! • Father of microbiology • Visualized bacteria under the lens of a rudimentary microscope • Important precursor to Germ Theory History: John Graunt • One of the first (not the only one!) to analyze London’s Bills of Mortality -> death statistics (1662) • Recognized seasonality of epidemics • Methods were rudimentary by today’s standards, but recognizing the need for numerical observation is key • The Bills of Mortality began late 1500’s after the plague, important source of demographic info (“Searchers”) > Earlier: church records Women collected information in their parish for returning to London – cause of death determined by them or priest History: Edward Jenner (1749-1823) • Father of immunology • In 1796 inoculated his gardener’s son with pus from a milkmaid’s cowpox blisters • He then injected the boy with pus from an active smallpox patient … and the boy was fine! • Vaccination eventually led to the eradication of smallpox • More on this in a later lecture History: John Snow (1813-1858) • Father of epidemiology (and anesthesiology) • August 1854 London was experiencing yet another cholera epidemic • Didn’t believe in miasma theory; thought cholera was spread by drinking water contaminated by fecal waste • Went door-to-door to ask where cholera cases were (shoe-leather epidemiology) • Realized that cases were concentrated around one source, the Broad Street Pump • The handle of the pump was removed (victory!) but cholera deaths were already declining so nobody believed him (failure!) • Why didn’t anyone believe him? • Everyone still a fan of miasma theory • No disease agent found (until 1883) History: Victorian London • The “Big Stink” (summer 1858) • Noisy, crowded, dirty, smelly, foggy, polluted • No sewers or clean water – human and animal waste in the streets • Windows covered up because of taxes (no sunlight) • Very, very poor people (children) everywhere • No wonder people believed in miasma theory! > Parliament closed and all the rich people went to the country Curtains soaked with lime Jack the Ripper, Charles Dickens, Dracula History: William Farr (1807-1883) • Also a Father of Epidemiology • The Registrar General of London • Emphasized consistency in Bills of Mortality • Refined the Life Table • His cause-of-death and injury classification system precursor to WHO’s International Classification of Disease (ICD) History: Life Tables (don’t need to know formulas) • A form of Event History Analysis • Provides life expectancy at birth/number of years remaining • A way to see how mortality changes with age History: Ignac Semmelweiss (1818-1865) • Also a Father of Epidemiology • A Hungarian Obstetrician • Drew a connection between “invisible invaders” and poor health • 1846: Compared maternal deaths in a clinic run by physicians (13%) to one run by midwives (2%) • Proposed puerperal fever was transmitted to women in labour by physicians who came directly from autopsies • In 1847 advised his students to wash their hands with lime. Mortality rates dropped. • A year later expanded practice to washing instruments also • Due to personal difficulties with other doctors and his own paranoia he was largely ignored • In 1865 he had a complete breakdown and was committed to an asylum for the mentally insane where he died. History: Louis Pasteur (1822-1895) • Father of microbiology • Demonstrated that fermentation caused by microorganisms (and not spontaneous generation) • Developed a heat treatment that killed microorganisms (ex TB) in milk … Pasteurization • His experiments supported GERM THEORY (supported research that microbes existed) History: Robert Koch • Also a Father of microbiology • Identified bacterium for tuberculosis (1882) and cholera (1883) • Death to miasma theory! • Koch’s postulates still used today to identify that a disease is caused by a microbe Koch’s Postulates • The organism must be present in every case of the disease but not in healthy individuals • The organism must be capable of being isolated from the sufferer and grown in pure culture • The specific disease must be reproduced when a pure culture of the organism is inoculated into a healthy, susceptible host. • The organism must be recoverable from the experimentally infected host Koch’s Postulates: Problems • Humans no longer linked to their environment (as with miasma theory) • Asymptomatic disease carriers • Introduced a new way to discriminate • Individual rights now secondary to the good of the community • Reductionistic: other factors no longer important in disease • A single microorganism can produce multiple diseases • Some organisms difficult to grow in culture Penicillin and Medical Reductionism • Penicillin discovered by Alexander Fleming • As early as 1928 he recognized that something had contaminated his staphylococcus culture and was preventing it from growing • WWII sped up the development and production of that contaminant, now called Penicillin • Amazingly effective cure for bacterial infections • The start of a pharmaceutical revolution