Nikazu,
First keep in mind what Pope Benedict XVI as Cardinal Ratzinger quoted in agreement:
“To seek a solution to the problem of infection by promoting the use of prophylactics would be to embark on a way not only insufficiently reliable from the technical point of view, but also and above all, unacceptable from the moral aspect.”
newadvent.org/library/docs_df88ai.htm
Second, she may be thinking of this document the relevant portions of which I link to below:
The Concern of some Moralists Raised by Studies Indicating that Condoms might not Provide Total Protection against the Transmission of HIV and STD’s
vatican.va/roman_curia/pontifical_councils/family/documents/rc_pc_family_doc_20031201_family-values-safe-sex-trujillo_en.html#ConcernMoralists
**The Same Concern, from non-Ecclesiastical Circles **
vatican.va/roman_curia/pontifical_councils/family/documents/rc_pc_family_doc_20031201_family-values-safe-sex-trujillo_en.html#ConcernNonChurch
The Workshop Summary: Scientific Evidence on Condom Effectiveness for Sexually Transmitted Disease (STD) Prevention
vatican.va/roman_curia/pontifical_councils/family/documents/rc_pc_family_doc_20031201_family-values-safe-sex-trujillo_en.html#WorkshopSummary
Condom Failure and its Latex Material
vatican.va/roman_curia/pontifical_councils/family/documents/rc_pc_family_doc_20031201_family-values-safe-sex-trujillo_en.html#Latex
If you read all these sections, or better the whole document, you’ll find the overwhelming mathematical and scientific evidence that shows that using condoms to prevent one’s self from contracting an STD from strictly the technical point of view is playing Russian roulette. Here’s one eye-opening excerpt:
“In their article, Fitch
et al emphasize that the cumulative risk factor is very significant. “For example, an intervention that is 99.8% effective for a single episode of intercourse can yield an 18% cumulative failure rate with 100 exposures.”
[38] Likewise, based on an International Planned Parenthood Federation (IPPF) article, “the risk of contracting AIDS during so-called ‘protected sex’ approaches 100 percent as the number of episodes of sexual intercourse increases”.
[39] IPPF is an institution promoting all forms of “birth control”.”
These data can easily be verified with a simple calculator:
1-(.998^100)=.18143…
or a little over 18%
The “approaches 100 percent” datum can also easily be proved mathematically.