Disease Surveillance

1. Broad Outlines (Mark)

   Focus on epidemiological aspects

2. Disease surveillance in Time, in Space, and in Space-time (Geoff)

   This portion of the lecture motivates questions regarding disease cluster and surveillance approaches

   1. Background and recent history

      In 1989 the `Cluster Busters' conference was held in Atlanta, Georgia. This was the first conference to address the issue of disease clustering, and brought together practitioners from around the nation. Out of this emerged a working group charged with formulating guidelines for disease surveillance and clustering. (reading 1)

   2. What is a cluster?

      1. Aggregation in time, space, space and time, space-time interaction, surveillance
      2. Time clustering (Example: Bones.tim).
      3. Space clustering (Example: Humberca.pnt and Humberco.pnt)
      4. Space clustering and time clustering
      5. Space-time interaction (Epidemic.pnt)
      6. Surveillance (when do we sound the alarm? Example from Rogerson's paper)

   3. Cluster Characteristics

      Clusters arise for different reasons: perceived vs. true clusters What happens to cluster investigations? Only a fraction reveal a `true' cause.

   4. Role of cluster investigations

      1. Respond to concerned public
      2. As tool for allocating public health resources: Criteria for stopping

   5. The Texas sharpshooter problem

      Motivation with an example. Use a Poisson spatial point distribution, view it, use a focused test to reveal a cluster -- this is not a true cluster, illustrates Texas sharpshooter.

   6. Sobering thoughts for cluster busters

      1. Reporting of clusters is biased.
      2. Few cluster investigations result in `significant' findings.
      3. Most methods ignore exposure to causal agent!

Page by Andy Long. Comments appreciated.