Lecture 2: Intro to Epi Flashcards
What is the epidemiological approach?
-Ppl are drowning in a fast moving river
-Downstream; heroic attempts at rescue and resuscitation but
-what is happening up stream that resulted in ppl falling in
-Epidemiology is walking upstream to figure out
What does epidemiology mean?
-the study of the frequency, distribution and determinants of health and disease in populations
-The application of this study to the control of health problems
Why was epidemiology used thousands of years ago?
-Has been used throughout the ages to characterize and solve numerous human (and animal) health problems
Who was Edward Jenner and how did he contribute to the epidemiologist “hall of fame”?
-“father of immunology”
-late 18th century: to try and prevent smallpox (SP)
-Variolation (infect individuals with SP material some died, infected others or become infected with other infections)
- Exposure to cowpox prevented infection with smallpox SUCCESS
-Vaccination refers to inoculation w/ vaccinia (aka cowpox)
Who was James Lind and how did he contribute to the epidemiologist “hall of fame”?
-“Father of Nautical Medicine” (maritime medicine; care of sick and injured patients on a variety of seafaring vessels in remote areas of the world)
-He worked as a doctor in Royal Navy-observed many cases of scurvy
-Did I trial in treatment in 6 groups of 2 (treatments included vinegar, sea-water, vitriol, garlic, citrus fruits)
-Citrus group recovered in ‘dramatic fashion’ but ppl didn’t believe right away, they still though scurvy was caused by faulty digestion so they dismissed it
-until vit C was identified, and navy adopted the policy of issuing citrus fruits in ships
Who was Sir Percival Pott and how did he contribute to the epidemiologist “hall of fame”?
-Best known for “Potts fracture”
-English Physician in London
-Made early accounts demonstrating cancer might be caused by an occupational carcinogen
-Observed a high incidence of skin sores on scrotum of men working as chimney sweeps that has coal soot in the sores
-Concluded that chimney sweeps were at high risk of cancer
-His work lead to the :chimney Sweepers Act” to protect workers
Who was John Snow and how did he contribute to the epidemiologist “hall of fame”?
-“father of modern Epidemiology”
-Anesthesiologist, his true love epi of cholera (acute diarrhea illness cause by infected water or food but they didn’t know that at the time)
-1800 in London very poor sanitation, British doctors not familiar with symptoms/prognosis of cholera
-Though it was “bad air” but Snow didn’t believe it based on what he witnessed (him and others not getting ill when attending patients, disease started in gut so must be consumed suspected waterborne transmission
-Snow explored area and interview cases for more info, made maps where cases were
-later discovered water was polluted with sewage and when a handle was removed from a street pump the number of cases immediately diminished (ppl couldn’t drink the infected water)
What is the “black box epidemiology”? and how is it related to John Snow?
-Vibrio cholerae was unknown and so was germ theory but by meticulously gathered data lead to the end of cholera in Britain
-Snows work demonstrates the value of the analysis of natural experiments/observational studies and that interventions don’t require a full understanding of a disease process
Who was Ignaz Semmelweis and how did he contribute to the epidemiologist “hall of fame”?
-“father of Infection control”
-Physician working in obstetrical clinic at Vienna General Hospital
-Observed high incidence of puerperal fever (aka child fever) postpartum infection
-Semmelweis’s did an investigation in 2 maternity wards in Vienna general hospital (1 w/ midwives and 1 w/ med students and male doctors)
-Moms in the med student hospital, died from childbed fever 5x higher than the other hospital
-He compared the 2 hospital and the major difference was after death, doctors and med students conducted autopsies sometimes before attending patients but midwives didn’t
-His solution was chlorine to disinfect any “Cadaverous particles” on their hands before attending deliveries
-Cases dropped but his conclusions were not well accepted (bc 1. it made doctors look bad 2. he berated ppl who didn’t agree with him 3. his theory went against scientific consensus aka bad air theory that they believed)
-Doctors eventually stopped washing their hands and Semmelweis lost his job
What happened after Ignaz Semmelweis’s death that lead to the discovery of cause for childbed fever?
-After he died 3 ppl (Louis Pasteur, Joseph Lister, and Robert Kock) provided evidence for germ theory (microorganisms aka germs can lead to disease)
-in 1879, Louis Pasteur isolated Streptococcus from the blood of women with child fever
What are the epi approaches overtime?
1800’s
-Communicable diseases (illnesses that spread to from person to person, or animals, surface, food etc in the form of viruses, bacteria, fungus, or protozoa)
1950’s
-Chronic diseases & seroepidemiology (use of data on the prevalence of bio-markers of infection or vaccination, powerful tool to understand the epi of infection before vaccination and to monitor the effectiveness of vaccination programmes)
1980’s
-Clinical epi & Pharmacoepi (study of the uses and effects of drugs in well-defined populations)
1990’s
-Molecular, genetic & social epi (social epi: branch of epidemiology concerned with the way that social structures, institutions, and relationships influence health)
How do epidemiologists play a role in COVID-19?
1) Initial investigation of pneumonia-like symptoms in Wuhan
2) Modelling projections (case numbers and interventions)
3) Informing public health policy
4) Surveillance and contact racing
5) Genomic sequencing
6) Vaccine development and administration
