Effectiveness of low sensitivity interventions in west Africa Ebola epidemic

Richard Williams, a student from Morehouse College, worked with Dr. John Drake to develop a model examining the effectiveness of low-sensitivity interventions in disease outbreaks.

Abstract: We conducted a theoretical study to investigate the effect of low sensitivity interventions on the containment of an emerging pathogen. Low sensitivity interventions  such as thermal scans for febrile patients in airports are outbreak interventions that may yield many false negatives, and are implemented because of their political or logistical feasibility. The first step of our study was to derive a discrete-time SEIR model for transmission at a given site and develop computer code to implement the associated stochastic simulation algorithm. We next developed a simulation program to link multiple sites updated as in the first step, incorporating pairwise movement probabilities between sites (which may be randomly constructed or data-driven) and an intervention that prohibits movement based on low sensitivity diagnostic (thermal scans) with tunable sensitivity and specificity. For reporting, this code also tracks the number of uninfected persons incorrectly denied permission to travel. In future work, this software will be used to compare the effectiveness of low-sensitivity interventions applied to pathogens with a range of incubation periods.


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