11-08-2012, 11:52 AM
Epidemiology
Epidemiology.ppt (Size: 1.23 MB / Downloads: 35)
Emerging Infectious Disease
Mutation of organism to new serovar (antigenic type)
Migration of humans and animals into new environments
Travel
War and natural disasters
Decline in vaccination rates
Climatic changes
Cholera: the Disease
Entry: oral
Colonization: small intestine
Symptoms: nausea, diarrhea, muscle cramps, shock
London in the 1850’s
Germ theory of disease not widely accepted
People lived in very crowded conditions with water and privies in yard (NY 1864: 900 people in 2 buildings 180’ deep x 5 stories – 1 pump a block away, privy in yard)
Cholera Epidemiology
Of 83 people, only 10 lived closer to a different pump than Broad Street
Of these 10, 5 preferred taste of Broad Street water and 3 were children who went to nearby school
The Great Experiment
Lambeth Company: water intake upstream of London sewage outfall into Thames
Southwark & Vauxhall Company: water intake downstream of sewage outfall