Conclusions: Raccoon Rabies

  1. Rabies entered Connecticut in 1991, and spread across the state in an epidemic wave. Rabies has now entered an endemic phase in Connecticut.

  2. Modeling Overview
    1. Question: how fast was the front moving?
      Answer: Linear regression for rabies arrival in a given town

      The epidemic front was modelled as a linear wave travelling at about 46 km/yr, from southwest to northeast:

      y = mx + at +b
      with a good fit (R-squared: 0.841304).

    2. Question: What happens when the front hits a town?
      from linear regression we derive a local impact curve (a kendall)

    3. Question: What can we learn from modelling the kendall?
      • Predictions of
        • peak reported cases, and time to peak
        • asymptotic case load
        • time to endemic period

    4. Question: can we confirm that rivers delay the spread?
      • We can't show this with the linear model (speed is constant)
      • We use a non-linear regression (kriging) for rabies arrival in a given town to answer in the affirmative.

    5. Question: is there a seasonal effect?
      • We use non-linear regression (periodic) for rabies arrival to conclude that the seasonal effect is significant.
      • We reexamine the river effect to answer in the negative.

  3. Present and future work:
    delay equations for rabies arrival in a given town
    guide/target: kendall

  4. Thanks!