A mathematical model for simulating virus transport through synthetic barriers

Synthetic barriers such as gloves, condoms and masks are widely used in eff orts to prevent disease transmission. Due to manufacturing defects tears ar ising during use, or material porosity, there is inevitably a risk associat ed with use of these barriers. An understanding of virus transport through the relevant passageways would be valuable in quantifying the risk. However , experimental investigations involving such passageways are difficult to p erform, owing to the small dimensions involved. This paper presents a mathe matical model for analyzing and predicting virus transport through barriers . The model incorporates a mathematical description of the mechanisms of vi rus transport, which include carrier-fluid flow, Brownian motion, and attra ction or repulsion via virus-barrier interaction forces. The critical eleme nt of the model is the empirically determined rate constant characterizing the interaction force between the virus and the barrier. Once the model has been calibrated through specification of the rate constant, it can predict virus concentration under a wide variety of conditions. The experiments us ed to calibrate the model are described, and the rate constants are given f or four bacterial viruses interacting with a latex membrane in saline. Rate constants were also determined for different carrier-fluid salinities, and the salt concentration was found to have a pronounced effect. Validation e xperiments employing laser-drilled pores in condoms were also performed to test the calibrated model. Model predictions of amount of transmitted virus through the drilled holes agreed well with measured values. Calculations u sing determined rate constants show that the model can help identify situat ions where barrier-integrity tests could significantly underestimate the ri sk associated with barrier use. (C) 1999 Society for Mathematical Biology.