Identification of the cholera diffusion process in Ibadan, 1971

Area of Science:

• Epidemiology
• Spatial Analysis
• Public Health

Background:

• Cholera outbreaks pose significant public health challenges.
• Understanding disease diffusion patterns is crucial for effective control.

Purpose of the Study:

• To identify the primary spatial diffusion process responsible for the 1971 cholera epidemic in Ibadan City.
• To analyze the wave-like spread of the epidemic using spatial autocorrelation statistics.

Main Methods:

• Employed Moran's I statistic, specifically the BW join-count measure of spatial autocorrelation.
• Utilized five different planar graph models to analyze spatial diffusion patterns.

Main Results:

• Contagion was evident across various spatial process models and their combinations.
• Radial contact diffusion was identified as the most significant factor in epidemic spread.
• During the epidemic's peak and spread phases, a mixture of diffusion models best explained the contagion.

Conclusions:

• Radial contact diffusion is a key mechanism in cholera epidemic spread in urban settings.
• The dominant diffusion process can shift during different phases of an epidemic wave.
• A combination of spatial diffusion models provides a comprehensive understanding of epidemic dynamics.