Summary
Objective:
The objectives of epidemiological surveillance and research of infectious diseases
are to address disease prevention, identify outbreaks and monitor and evaluate control
strategies. In this paper, we report on the development of a Geographical Information
System (GIS) based on a novel Digital Ring Fence (DRiF) strategy for the containment
of acute infectious diseases.
Method:
Data from probable cases are captured in a secure database. Postal codes of addresses
facilitate precise mapping of the location of each probable case on a multi-layered
GIS system. A digital ring fence is constructed around each location (hot-spot) using
Non-Homogeneous Poisson Process (NHPP) modeling based on data of individuals coming
into contact with each probable case. The radius of the DRiF gives the overall risk
of infection from its epicenter, the probable case. By annotating the DRiF to a GIS,
areas of population concentrations could be readily identified to direct outbreak
containment efforts.
Results:
Simulation studies have demonstrated that the DRiF strategy could provide a novel
approach to containment of acute disease outbreaks.
Conclusion:
SARS has provided convincing evidence that the key to tackling acute infectious disease
outbreaks lies in containment and making disease containment one step ahead of its
spread. The DRiF strategy achieves this by providing a zone to corral the spread of
infection through person-to-person transmission. Other useful applications of the
DRiF technique include demarcating culling zone for the containment of bird flu infection
and containment of person-to-person transmission should it occur.
Keywords
Outbreak containment - ring-fence - SARS - bird flu - infectious diseases - epidemiological
modeling
