Stats 11, Winter 2004

Experimental Design

Jan 9, 2004

London Cholera Outbreak, 1854

• Cholera kills quickly

• Primary symptom is severe diarrhea

• Modern treatment involves an IV to provide hydration

• Competing Theories for transmission: air vs water (germs). Air was the predominant view.

Golden Square, Sept 1854

• Unusually intense, deadly outbreak

• 500 deaths in just a few days

• Local panic made neighbors flee

• John Snow, a physician, believed cholera spread through polluted water supplies

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Is this definitive "proof"?

Same picture, but with daily deaths

Aside: quarterly aggregates

Fiscal Year aggregates

Calendar Year aggregate

Water compnies

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This area was fed by two water companies

Deathrate less where clean water

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Current medical mystery

• Sudan's Luckless Children, Locked in Land of Nod, NY Times, Sept 22, 2003

• Mysterious ailment among some children of Sudan

• Nod, don't grow fully, die in late teens• Theories: fly bite, poison,

contaminated food

References found on

• http://www.ph.ucla.edu/epi/snow.html