A simple method to test condoms for penetration by viruses

Abstract

A method by which virus penetration through condoms can be tested with simple, inexpensive equipment is described. The method uses chi X174 bacteriophage as the challenge virus and physiologically relevant pressure. Penetration by 0.1 microliters (or less) of challenge suspension can be readily detected. As examples, latex and natural-membrane condoms were examined.

Minimized virus binding for tests of barrier materials

“…The anionic FC-129 and the cationic FC-135 are Fluorad fluorochemical surfactants (3M, St. Paul, Minn.), which were generously provided by S. M. Retta, Center for Devices and Radiological Health, Food and Drug Administration. Triton X-100 has been used as a surfactant in a test of condoms as virus barriers (10), as have Tween 80 in the American Society for Testing and Materials test of surgical gown material as virus barriers (2) and FC-129 in the test of condoms as barriers to microspheres of the size of human immunodeficiency virus (13).…”

“…In the test protocol developed in our laboratory (10), the Poiseuille equation for fluid flow through a cylindrical hole indicates that only 1 nl (10 Ϫ6 ml) of challenge virus suspension can penetrate a single hole with a diameter of 0.6 m in a latex condom in 30 min. Thus, since spherical virus particles are substantially smaller in diameter than 0.6 m, it is fluid flow and not virus size that is the limiting factor for virus penetration through a single hole.…”

“…One can determine through control experiments whether loss of virus through adsorption occurs during exposure of the virus suspension to the surfaces of the test material (latex in this example) or to other components of the test apparatus (10). However, it is not practical to investigate virus adsorption resulting from the close proximity inherent during passage through small, natural, rare, randomly occurring defects in the material.…”

“…The goals of this study were (i) to identify which potential surrogate virus adsorbs least in saline to binding membranes and (ii) to identify conditions that minimize virus adsorption, including additions of surfactants, serum, or culture broth. The choice of additives was governed by the use of surfactants or culture broth in established tests of barrier materials (2,10,13) and the likely presence of serum or some other body fluid during real-life use of a barrier material (e.g., serum during use of a medical glove or serum and semen during use of a condom). Virus adsorption was determined using binding membranes as filters in a filtration protocol previously used with sizing filters (11).…”

Concentration and detection of hepatitis A virus and its indicator from artificial seawater using zeolite

“…While Triton X-100 would be expected to affect nonionic adsorption only, the anionic SDS would be expected to affect both ionic and nonionic adsorption and specifically counteract the adsorption forces (American Society for Testing and Materials, 1995;Fujito, B.T., Lytle, C.D. 1996;Lytle et al, 1992;Retta et al, 1991). Unlike Triton X-100 and Tween 80, SDS denatures protein in addition to solubilizing them.…”