GIS Applications for Infectious Disease and Conflict Situations

1
GIS Applications for Infectious Disease and
Conflict Situations
Source MALSAT
2
Definitions

• Infectious disease vs. chronic disease
• Risks factors which show a strong correlation
  to disease onset. Causality is difficult to
  prove.
• Risk Assessment likelihood that a
  region/population will develop a disease. Based
  on probability.
• Vulnerability Analysis incorporates risk
  assessment but also includes capacity to respond.

3
Mapping of Health Data

• Opportunities to study spatial distribution
• Associations between environmental exposure
• Comparison of disease rates or exposures across
  regions at group level
• Estimate exposures
• Target interventions and plan policy based on
  risk assessment and vulnerability analysis

4
Spatial Distribution

• Can show non-random distribution
• Suggests possible exposures or disease source
• May point to epi-center
• Can show spread of disease

5
John Snow and cholera casesGolden Square area of
LondonAugust September 1854
6
Prince Williams County Measles Epidemic 1988
Source Prince William County Fire Rescue
7
Mapped by School
8
Two Week Elapsed Period
9
Association with Environmental Exposure

• Demonstrate risk of disease
• Useful for monitoring and surveillance
• Useful in selection of subjects for different
  study designs
• Model exposure patterns

10
Kenya risk of malaria based on inhabited areas
11
Risk associated with meningitisAuckland, New
Zealand
Source Auckland Public Health Protection
12
Residential distribution in relation to
forestsLyme disease
Source G.E. Glass et al 1995
13
Selection of Study Subject

• Wartenberg used digitized powerline network
• 100 meter buffer
• Selections for cohort study

14
Comparison of HIV/AIDS
15
Modeling Anthrax ExposureSverdlovsk, U.S.S.R.
Source Messelson 1994
16
Probability of Malaria Exposure
Source Omumbu, 1998
17
Ethical Issues

• Protect identity of study subjects
• Critical in small studies studies in developing
  countries
• Randomizing algorithms, manual shift, etc.

18
GIS Applications in Complex Human Emergencies

• Environmental Impact Assessment
• Food scarcity disruption of agriculture
• Infrastructure, hydrology and location of
  protected areas
• Overcrowding, resource depletion potential for
  conflict escalation

19
UNHCR Planning for Refugee Settlements

• Scale typically poor spatial resolution
  (11000000) so limited use in local planning
• DRC and Tanzania using SPOT images for smaller
  scale
• Cost is high
• Kenya mapped with aerial photos and digitized
  settlement plans

20
UNHCR Planning for Refugee Settlements

• Mozambique incorporating GPS into tracking
  cholera and dysentery in settlements
• Questionable scale
• Potential for health impact forecasts to impact
  bombing site selection
• Disease risk tied to demobilization