CAS BI 114 Lecture Notes - Lecture 9: Coronavirus, Louis Pasteur, Miasma Theory
30 Apr 2018
School
Department
Course
Professor
Epidemiology
Studying Infections
•We are a big and teeing microbe islands in a big microbe-infested world
•How do we figure out: What is making us sick? Where it came from? How to stop it?
Timeline for Microbial Discovery
•1854 - Nurse Florence Nightingale (1820-1910) was sent to the Crimean War to figure out why 42%
of the hospitalized soldiers died before returning home
•Studied the rates of death among British soldiers during the war
•Hypothesized that nutrition and sanitation were important components of health
•Soldiers were not eating protein nor proper portions for their bodies to recover
•Hospitals were filthy and ridden with blood, which meant bacteria must have been thriving
•Advocated sanitary conditions among the poor and in hospitals around England
•While she was away, there was a Cholera outbreak in a London neighborhood
•Miasma (bad air) was thought to be the cause leading everyone to flee the area
•1854 - John Snow “Father of Epidemiology” (1813-1858) wanted to figure out what was causing this
outbreak
•Although everyone believed it was miasma he hypothesized it had something to do with the water
supply
•Determined the Cholera outbreak was not because of miasma but because of the water source
•This was an early basis for the germ theory of disease
•Led to the creation of the Scientific Method, Observation & Data Gathering as important pieces
to solving a puzzle
•1860 - Louis Pasteur (1860-1864) hypothesized that there were germs behind every illness (The Germ
Theory of Disease)
•Discovered that bacteria were the agents behind childbed fevers and other diseases
•Created the swan-necked flask
•Experimented with this in order to show that the spontaneous generation was false and that there
were bacterium in the air
•1870s - Joseph Lister began to advocate for the cleanliness in hospitals which would lead to an
effectiveness in treating soldiers/patients
•Soon created The Aseptic Technique
•Robert Koch put all these above ideas together and put together Postulates (a list of questions) in
order to test if a disease is caused by microbes
•Do microbes cause disease?
•Does every case of the disease have the same microbe?!
Can you isolate the microbe and grow it in a lab to study its properties?
•Can you inoculate a healthy animal with a microbe and does it get sick?
•Can you re-isolate the microbe and grow it in a lab; and will it be the same as the original
microbe?
•However, these postulates do not account for viruses
Determining Causative Agents
•Using genetics to find causative agents
•Common among all infections
•Enabled us to ID previously unknown infectious agents (ex: SARS virus outbreak in 2003, a novel
corona virus)
Modern Epidemiology
•Global travel, everyday interactions, online habits (tracking patterns of Google searches to determine
the beginnings of a pandemic)
•Some diseases must be reported to the CDC (ex: measles)
•***CDC (Center for Disease Control) - funded by the department of Health and Human Resources
find more resources at oneclass.com
find more resources at oneclass.com
