Virus Transmission Through Compromised Synthetic Barriers: Part II—Influence of Pore Geometry

Journal of Biomechanical Engineering -- October 2001 -- Volume 123, Issue 5, pp. 513-518

Bigyani Das and Matthew R. Myers
Center for Devices and Radiological Health, U.S. FDA, HFZ-132, 12725 Twinbrook Parkway, Rockville, MD 20852

(Received July 6, 2000; revised May 16, 2001)

When stressed during normal use, synthetic barriers such as gloves and condoms can develop tears that are undetectable by the user. It is of considerable public-health importance to estimate the quantity of virus transmitted through the tear, in the event of viral contamination of the fluid medium. A mathematical model that accounts for virus adsorption to the barrier material was used to compute the quantity of virus transmitted through defects of various geometries. Slits were modeled as cylinders of elliptic cross section, and upper and lower bounds for the transmission rate of HIV and Hepatitis B virus (HBV) were calculated for barrier-use scenarios such as coitus and gripping of surgical instruments. For a 1-µm high slit, HIV transmission was found to be negligible for all likely use scenarios. HIV transmission became potentially significant for a 5-µm slit. Due to its high titer, HBV transmitted at potentially important levels even through the 1-µm slit. The dependence of the transmission rate upon pore aspect ratio was determined and found to be very strong for high-adsorption situations and near-circular pores. Numerical predictions of virus transport through a laser-drilled hole in a condom matched experimental measurements well, even when the tapered nature of the geometry is ignored.