Impermeable barrier, colander, or something in between?
The Catholic Church came under fire recently when a BBC report quoted that “cardinals, bishops, priests and nuns in four continents of the church have been quoted as saying HIV can pass through tiny holes in condoms.”
Cardinal Alfonso Lopez appeared on the program stating, “The AIDS virus is roughly 450 times smaller than the spermatozoon…The spermatozoon can easily pass through the ‘net’ that is formed by the condom.”
Where did Lopez and others get this idea? Turn to Catholic.org’s apologetics section. Included in the page on Contraception is the following passage, taken from Briefing Paper No. 4, Bishops’ Conference of Scotland:
The AIDS virus is many times smaller in size than the naturally occurring holes in a latex condom and so can freely pass through the holes in the condom. “Sperm have a diameter of 50 microns. Naturally occurring holes in the wall of a latex condom have a diameter of 1.0 microns. The HIV retrovirus which causes AIDS has a diameter of 0.1 microns. In effect, this would be comparing perhaps an ant crawling on a basketball. AIDS viruses swim freely through the holes of the condom. That is a fact that should be widely publicised”. (CM Roland, Editor, Rubber Chemistry & Technology, Washington Times, 22/04/1992)
Roland’s claim is similar to findings reported in the 1988 issue of Nature. In the article “Latex gloves not enough to exclude viruses” (no link available – unless you want to buy the article), Susan G. Arnold and James E. Whitman, et. al. report studies by the National Institutes of Health and Georgetown University that found that latex surgical gloves have naturally occurring channels up to five microns across.
I doubt that latex manufacturing has since improved sufficiently to eliminate the channels. But there’s two questions nobody seems to be addressing. First, what percentage of the surface are of a latex condom or glove has these channels? This leads up to the second question: what is the likelihood that viruses will enter those channels?
Disease control should never place all its eggs in one basket. What is at issue is not whether Plans B, C, D, and E are needed at all, but the degree to which Plan A’s shortcomings necessitate their inclusion into policy.
Self-Pollution. 
Strange that condoms hold water. A water molecule would seem to be a great deal smaller than any virus. And they hold air. I suspect that there’s something else going on, and it’s not just surface tension. Perhaps it takes so long for those particles to travel the length of the channel that there is no effective leakage?