Medical Geography

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Medical Geography

• Introduction

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Medical Geography

• Developed from the work of Dr. John Snow
• Trying to stop the transmission of cholera
• 1854- outbreak of cholera in London
• Dr. Snow plotted the deaths from cholera on a
  map, determining an unusually high number of
  deaths were linked with a particular water pump-
  on Broad St.
• He petitioned to have the pump closed, which led
  to a drastic decrease in new cholera deaths.
• One of most famous and earliest instances of
  using maps to understand spread of disease

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Snows Cholera map
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Worldwide causes of death

• medical geographers measure health strictly in
  terms of morbidity (illness and disease
  complications) and mortality (death).
• In addition to diffusion over space, they also
  focus on diffusion over time- known as
  spatio-temporal mapping and analysis

Developed countries
Developing countries
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Definitions

• epidemiology - study of occurrence, distribution,
  and control of diseases in populations
• origin, spread or communication, and eradication
  of disease
• incidence - number of diseased individuals in a
  defined population
• endemic - constantly present disease
• epidemic - abnormally high incidence locally
• pandemic - abnormally high incidence over a wide
  geographic area (worldwide?)
• vector- agent used as a vehicle for transfer.
• (disease vector agent that transfers a pathogen
  from one organism to another (e.g., an insect))
  can also be viral, including a live virus used as
  an antigen delivery vehicle in a vaccine

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Recent worldwide outbreaks of disease
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Historical aspects

• Paleolithic- low populations/ good diets keep
  diseases from becoming endemic
• Neolithic- population density increases, animal
  domestication occurs, diets deteriorated
  (dependence on grains mainly), water borne
  diseases
• Imperial period- trade increases, urban areas
  become more unhealthy
• Medieval- plague, trade decreases, population
  decreases, epidemics frequent but less virulent
• Exploration- introduction of disease to virgin
  populations, trans-Atlantic slave trade

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More Historical geographies

• Industrial Age- more trade-gt more diffusion of
  disease, urban slums (diet and exhaustion),
  endemic diseases become childhood ones, rapid
  population growth, hygiene
• Today

Factors Contributing To New Infections

1. Population Growth
2. Urbanization
3. Expansion Into New Areas
4. Ecological Changes
5. Reduced Biodiversity
6. Microbial And Vector Resistance

• Water Pollution
• Global Warming
• Ozone Hole
• Public Health Deficiencies
• War
• Transport
• Other Changes

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Risks?

• Complacency with endemic disease?
• Non-vaccinated groups?
• Antibiotic resistant strains?
• New Epidemics?
• Danger related to means of transmission
• Direct contact (person to person) containable
• Water and food borne- contained with adequate
  public health measures
• more difficult to control vectors.
• Air-borne diseases pose the greatest threat.
• Influenza greatest threat?
• Germ warfare?

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Control of Epidemics

• Improved resistance
• Improve nutrition reduce population
  concentrations lighter work loads
• Control Reservoir
• Reduce mosquitoes and their breeding grounds
• immunize animals (e.g. rabies)
• Control transmission
• direct contact (including STDs)
• Food, water, air, feces
• Immunizations
• Recommended for Foreign Travel
• cholera, yellow fever, plague, infectious
  hepatitis A, serum hepatitis B, typhoid fever,
  malaria