Scenario: spatial diffusion of AIDS
Source: P. Gould, 1993, The Slow Plague, Blackwell; out of print.
Spatial diffusion of disease describes the process by which a disease
concentrated in one location on the Earth's surface spreads out over a wider
area. The general principles that appear to underlie this spread mechanism
in human populations include contagion, waves, corridors, barriers, and
hierarchical structuring. Description of these principles about the way
things spread can be supplied by maps, written text, and/or algebraic
equations. This book tracks and maps one of the most catastrophic
pandemics, the origin and spread of AIDS, a disease whose consequences are a
matter of life and death. Four case studies at different geographic scales
are used, namely Africa, Thailand, the U.S., and the Bronx (NY). These
studies include interesting maps demonstrating the spread of AIDS through a
population. Gould explains how the HIV virus jumps from city to city, the
devastating consequences of misconceptions about its spread, and how
understanding its changing pattern over time can give a vivid sense of where
the disease threatens next. The hierarchical diffusion component is
effectively visualized in Figure 4.8 (p. 39) and Chapter 9 (especially pp.
116-120).
Principal concepts: hierarchical diffusion (pp. 63-4, 67, 70, 74,
83, 111,
114, 193, 195), computer modeling (pp. 14, 122, 156, 158-66, 171),
contagious diffusion (pp. 62-4, 70, 111, 122, 126-7, 193, 195), corridors of
infection (pp. 67, 70, 114-121).
Questions:
- Why does AIDS leap when it diffuses?
- What illuminations beyond those obtained from medicine and epidemiology
does a geographic perspective supply about the AIDS pandemic?
- What are the advantages of using maps as well as time series of cases
when studying an epidemic?
- How can maps be used to monitor intervention success?
- What are the barriers and channels for AIDS diffusion in the U.S.?
Return to Scenerios
