Title: A Tick-Borne Disease Model - Spread and Control of Ehrlichiosis
Speaker: Holly Gaff, University of Maryland
Date: February 5, 2007 12:00 - 1:30 pm
Location: DIMACS Center, CoRE Bldg, Room 431, Rutgers University, Busch Campus, Piscataway, NJ
Recent increases in reported outbreaks of vector-borne diseases throughout the world have led to increased interest in understanding and controlling epidemics involving transmission vectors. Ticks have very unique life histories that create epidemics that differ from other vector-borne diseases. The differential equations underlying our tick-borne disease model are designed for the lone star tick (Amblyomma americanum) and the spread of human monocytic ehrlichiosis (Ehrlichia chaffeensis). Analytical results show that under certain criteria for the parameters, the epidemic would be locally stable. The system was then expanded to multiple patches to evaluate the effect of spatial heterogeneity on the spread of the disease. The use of control measures was added, and it was found that the relative success of disease eradication was dependent upon the patch structure and location of control application. Results from simulations using a twelve patch system are compared with field data from an outbreak of ehrlichiosis in eastern Tennessee, USA. Finally, optimal control techniques are used to evaluate the location and amount of control needed to eliminate the disease from different patch scenarios. There remain many open questions that can be addressed by using this model that we have just begun to explore.
see: DIMACS Computational and Mathematical Epidemiology Seminar Series 2006 - 2007