Models of STD transmission

Condoms are made to withstand the rigors of sex. But the models used by
governments to test condom durability have nothing to do with sex.

Even if the models used to test condoms are reasonable indicators of
whether a condom will break during sex, and thus whether they will
function adequately in preventing sperm from reaching the female's
reproductive system, but they may be rather poor indicators of whether a
microscopic pathogen can pass from one partner to the other.

For example, the water test can detect holes only as small as 5 mm, but
this sized hole is many times the size of sexually-transmitted viruses and
even of the bacterium Chylamidia.

Similarly, the airburst test is insensitive to small holes. So here we
find new limitations of existing methods of testing condoms: these models
don't give us a good understanding of the barrier to pathogens afforded by
a condom.

That is, these models have serious limitations when considering condoms as
barriers to infectious disease.

http://www.utexas.edu/courses/bio301d/Topics/Condoms/Text.html