Condom effectiveness
AIDS NEWS SERVICE
Michael Howe, MSLS, Editor
AIDS Information Center
VA Medical Center, San Francisco
(415) 221-4810 ext 3305
September 2, 1994
Safer Sex: Information for Counselors
(Part VI)
REFERENCES - CONDOM EFFECTIVENESS
AU - Thompson JL. et al.
TI - Estimated condom failure and frequency of condom use among
gay men.
AB - OBJECTIVES. Condoms are designed to bar transmission of the
human immunodeficiency virus (HIV), but they sometimes fail. This
paper explores the effect of experience with condoms on condom
failure among gay men. METHODS. Risk of condom failure (breakage
or slippage) on a single occasion is estimated for four sexual acts
reported over 12 months by a sample of gay New York City men (n =
741). The estimation procedure assumes that each episode in which
a condom is used is an independent event. Evidence is offered to
support this assumption. RESULTS. Risk of condom failure in a
single episode was fairly high, particularly in anal intercourse,
for men who had engaged in each act only a few times in the
previous year. It declined rapidly with experience (e.g., to below
1% for receptive anal intercourse after about 10 episodes in the
previous year). Condoms failed less often in oral than anal sex,
but estimated risk of failure also decreased with experience.
CONCLUSIONS. Gay men should be especially cautious the first few
times they use a condom; after moderate experience, however, they
may expect a low risk of condom failure.
SO - Am J Public Health 1993 Oct;83(10):1409-13
AU - Weller SC
TI - A meta-analysis of condom effectiveness in reducing sexually
transmitted HIV.
AB - Before condoms can be considered as a prophylaxis for
sexually transmitted human immunodeficiency virus (HIV), their
efficacy must be considered. This paper reviews evidence on condom
effectiveness in reducing the risk of heterosexually transmitted
human HIV. A meta-analysis conducted on data from in vivo studies
of HIV discordant sexual partners is used to estimate the
protective effect of condoms. Although contraceptive research
indicates that condoms are 87% effective in preventing pregnancy,
results of HIV transmission studies indicate that condoms may
reduce risk of HIV infection by approximately 69%. Thus, efficacy
may be much lower than commonly assumed, although results should
be viewed tentatively due to design limitations in the original
studies.
SO - Soc Sci Med 1993 Jun;36(12):1635-44
AU - Richters J. et. al
TI - How often do condoms break or slip off in use?
AB - Men attending 3 sexually transmissible disease clinics and
a university health service in Sydney were given a questionnaire
asking how many condoms they had used in the past year and how many
broke during application or use or slipped off. Respondents were
544 men aged 18 to 54 years. Of these, 402 men reported using
13,691 condoms for vaginal or anal intercourse; 7.3% reportedly
broke during application or use and 4.4% slipped off. Men having
sex with men reported slightly higher slippage rates than those
having sex with women. Breakage and slippage were unevenly
distributed among the sample: a few men experienced very high
failure rates. A volunteer subsample reported 3 months later on
condoms supplied to them: 36 men used 529 condoms, of which 2.8
broke during application or use and 3.4% slipped off. Many of these
failures pose no risk to the user, especially those occurring
during application, as long as they are noticed at the time, but
failure may discourage future use. Research is needed to identify
user behaviours related to breakage.
SO - Int J STD AIDS 1993 Mar-Apr;4(2):90-4
AU - Boldsen JL. et al.
TI - Aspects of comfort and safety of condom. A study of two
thousand intercourses among volunteer couples.
AB - In nearly 2,000 intercourses 14 different types of condoms
were tested by 80 heterosexual and seven homosexual volunteer
couples. The test couples were generally quite experienced in the
use of condoms. It appears that the condoms rarely (1.3%) ruptured
or slipped off during the actual intercourse. This means that
emphasis must be put on consistency and skill in the use of condoms
rather on technical improvements in the promotion of condoms as a
means of preventing the spread of sexually transmitted infections
like HIV. Lubricated condoms and condoms that were not too small
were preferred by both users and their partners. Other condom
properties were significant but of minor concern for the
participants of the study.
SO - Scand J Soc Med 1992 Dec;20(4):247-52
AU - Carey RF. et al.
TI - Effectiveness of latex condoms as a barrier to human
immunodeficiency virus-sized particles under conditions of
simulated use [see comments]
AB - Condoms were tested in an in vitro system simulating key
physical conditions that can influence viral particle leakage
through condoms during actual coitus. The system quantitatively
addresses pressure, pH, temperature, surfactant properties, and
anatomical geometry. A suspension of fluorescence-labeled, 110-nm
polystyrene microspheres models free human immunodeficiency virus
(HIV) in semen, and condom leakage is detected spectrofluoro-
metrically. Leakage of HIV-sized particles through latex condoms
was detectable (P less than 0.03) for as many as 29 of the condoms
tested. Worst-case condom barrier effectiveness (fluid transfer
prevention), however, is shown to be at least 10(4) times better
than not using a condom at all, suggesting that condom use
substantially reduces but does not eliminate the risk of HIV
transmission.
SO - Sex Transm Dis 1992 Jul-Aug;19(4):230-4
AU - Russell-Brown P. et al.
TI - Comparison of condom breakage during human use with
performance in laboratory testing.
AB - This paper combines results from a study of the determinants
of condom quality and use conducted by The Population Council in
two countries in the Caribbean with results from a condom breakage
study conducted by Family Health International (FHI) in the United
States. The studies, conducted two years apart, compared the
breakage rates of condoms from the same lot during human use to
their performance in laboratory test results. Breakage rates of
12.9% for Barbados, 10.1% for St. Lucia and 6.7% for the United
States compared to passing ASTM laboratory tests suggest that
existing laboratory tests as used with the current pass/fail
standards are either not sufficiently sensitive or not well-defined
to reliably predict condom performance during human use. The study
also suggests that user behaviors and practices may be a factor in
condom breakage. If the condom is to be an effective method against
unplanned pregnancy and STD/HIV infection, and if consumer
confidence is to be retained, condom breakage during sexual
intercourse must be reduced.
SO - Contraception 1992 May;45(5):429-37
AU - Gerofi J. et al.
TI - A study of the relationship between tensile testing of
condoms and breakage in use.
AB - The ability of the condom wall to maintain its integrity
throughout sexual intercourse is critical to its role in halting
the spread of major sexually transmissible pathogens including the
human immunodeficiency virus. There are three principal in vitro
performance tests applied to condoms: a test for freedom from
holes, an inflation test, and tensile testing. In this study we
subjected condoms that had broken in use to tensile tests in order
to determine any correlation between their in vivo and in vitro
performance. Condoms which had broken in use showed similar tensile
properties to those which had not. All passed all tensile test
criteria. Thus, the inclusion of tensile testing in National
Standards for condoms is not sufficient to insure strong products.
SO - Contraception 1991 Feb;43(2):177-85
AU - Albert AE. et al.
TI - Condom use and breakage among women in a municipal hospital
family planning clinic.
AB - For those who choose to be sexually active, condoms are the
best available means of protection against sexually transmitted
diseases including the human immunodeficiency virus (HIV), which
causes acquired immunodeficiency syndrome (AIDS). Condoms are also
an effective method for preventing pregnancy. Unfortunately,
condoms are not 100% effective at preventing pregnancy or the
spread of infection, in part because condoms do break. In order to
gain insight into condom breakage, a questionnaire was administered
to women attending a municipal hospital family planning clinic.
Thirty-six percent of the 106 subjects had experienced at least one
condom breakage. Condom breakage occurred in approximately 1 out
of 100 acts of intercourse using condoms, with a lifetime breakage
rate of 10 per 1000 condom uses and a past year breakage rate of
8 per 1000 condom uses. Breakage rates did not differ substantially
by age. Five percent of the women's unplanned pregnancies were
attributed to broken condoms. The results of this study corroborate
previously reported rates. Factors associated with these women's
most recent breakage experiences included: vaginal intercourse,
minimal foreplay, and breakage prior to ejaculation. Controlled
studies will be needed to determine how the condom can be used to
reduce the likelihood of breakage.
SO - Contraception 1991 Feb;43(2):167-76
USE OF CONDOMS AND SPERMICIDES
This is a statement and answers to questions from the Centers
for Disease Control and Prevention (CDC) concerning the use of
condoms and spermicides for HIV transmission prevention.
The most effective barrier method to reduce the risk of
passing HIV and other sexually transmitted diseases is a latex
condom. Both lubricated (wet) and non-lubricated (dry) varieties
are effective. Lubricated condoms may also reduce the risk of
breakage and help minimize abrasion of the vagina.
Clinical studies have shown that spermicides used in the
vagina decrease the risk of cervical gonorrhea and chlamydia
infections. Laboratory studies have shown that spermicides can
destroy HIV when it is outside of cells, but these studies are
incomplete. There have been NO studies that demonstrate
spermicides' effectiveness against HIV during sexual intercourse
in humans. Spermicides' effectiveness against other STDs may be
influenced by the amount used, where it is put, and how much of
the vagina it covers. Spermicides are not a replacement for
condoms, but they could be considered an additional aid for
reducing STD and HIV risk.
To be most helpful, spermicide should thoroughly cover the
inside of the vagina. Spermicide applied directly inside the
vagina is the only way to achieve adequate coverage. The amount
of spermicide that is on a spermicidally pre-lubricated condom is
probably too little to stop sexually transmitted diseases. Use of
spermicides in the rectum has not been shown to be safe or
effective in preventing the transmission of STDs and HIV.
1. What is a spermicide?
A spermicide is a contraceptive; a birth control method that works
by killing sperm. It also has an effect against some types of
sexually transmitted bacteria and viruses.
2. How is it used?
Spermicide is available in creams, gels, foams, tablets, sponges,
vaginal contraceptive films (VCF), and suppositories which a woman
puts into her vagina before she has sex. Some lubricated condoms
also contain a spermicide. The amount of spermicide that is on a
prelubricated condom is probably too low to have much effect
against sexually transmitted diseases.
3. What Kind (brand) should I use?
Latex condoms are the recommended method of protection against
sexually transmitted infections, including HIV. If you choose to
use a spermicide in addition to a latex condom, the best kind to
use is a form where the spermicide can completely cover the inside
of the vagina, such as foams and creams. It does not matter what
brand you use as long as it is used according to the package
directions.
4. Can I use a spermicide without a condom?
No! We are more certain about the protection offered by latex
condoms. Spermicides' effectiveness against sexually transmitted
infections depends on a vagina and cervix being thoroughly covered
with spermicide. It is not always possible to guarantee complete
coverage, so putting spermicide in the vagina serves only as a
back-up to reduce, but not eliminate, the risk of infection in case
the condom leaks or breaks.
5. Can I use a condom without a spermicide?
Yes. Latex condoms, by themselves, provide an effective barrier
to reduce the risk of passing sexually transmitted infections.
Spermicides used with a condom may serve as a back-up to reduce
the risk of infection in the event the condom leaks or breaks.
6. Where do I put the spermicide? Inside or outside the condom?
How much?
If you decide to use a spermicide, put the spermicide IN THE
VAGINA, not on the condom. Spermicide should cover the inside of
the vagina thoroughly. Use as much as the package directs.
7. Are pre-lubricated condoms with nonoxymol-9 okay to use?
Latex condoms lubricated with nonoxynol-9 are as good as other and
lubricated, latex condom. Lubrication may reduce the risk of
condom breakage.
8. What is nonoxynol-9?
Either nonoxynol-9 or octoxynol is the active ingredient in most
spermicides. If you are using a spermicide as added protection
against sexually transmitted diseases and HIV, the amount of
spermicide that is on a condom is probably too little to help. It
is better to put spermicidal foam or cream directly into the
vagina.
9. Should a condom be used for oral sex?
A latex condom should be used during mouth-to-penis contact. There
are a variety of sexually transmitted diseases that can be passed
through this type of contact, including HIV.
10. Should you use a spermicide when engaging in oral sex?
A latex condom should be used during mouth-to-penis contact.
Spermicidal lubrication on the condom is not likely to increase
the protection provided by the condom. Do not use a spermicidally
lubricated condom for oral sex, and NEVER use a separate
application of spermicide in the mouth.
(Centers for Disease Control and Prevention, HIV/AIDS Prevention
Training Bulletin, April 23, 1991.)
REFERENCES - NONOXYNOL
(Arranged Chronologically)
Elias CJ. Heise LL. Challenges for the development of female-
controlled vaginal microbicides. AIDS. 1994;8:1-9.
Fisher AA. Allergic contact dermatitis to nonoxynol-9 in a condom
[news]. Cutis 1994 Mar;53(3):110-1.
Bourinbaiar AS. et al. Comparative in vitro study of contraceptive
agents with anti-HIV activity: gramicidin, nonoxynol-9, and
gossypol. Contraception 1994 Feb;49(2):131-7.
Stein ZA. Vaginal microbicides and prevention of HIV infection
[letter]. Lancet 1994 Feb 5;343(8893):362-3.
Jennings R. et al. The inhibitory effect of spermicidal agents on
replication of HSV-2 and HIV-1 in-vitro. J Antimicrob Chemother
1993 Jul;32(1):71-82.
Whaley KJ. et al. Nonoxynol-9 protects mice against vaginal
transmission of genital herpes infections. J Infect Dis 1993
Oct;168(4):1009-11.
Moench TR. et al. The cat/feline immunodeficiency virus model for
transmucosal transmission of AIDS: nonoxynol-9 contraceptive jelly
blocks transmission by an infected cell inoculum. AIDS 1993
Jun;7(6):797-802.
Resnick L. et al. Comparative evaluation of spermicidal agents with
virucidal activity against HIV. Int Conf AIDS. 1993 Jun
6-11;9(2):743 (abstract no. PO-C22-3154).].
Roddy RE. et al. A dosing study of nonoxynol-9 and genital
irritation. Int J STD AIDS 1993 May-Jun;4(3):165-70.
Zekeng L. et al. Barrier contraceptive use and HIV infection among
high-risk women in Cameroon. AIDS 1993 May;7(5):725-31.
Hochmeister MN. et al. Effects of nonoxinol-9 on the ability to
obtain DNA profiles from postcoital vaginal swabs. J Forensic Sci
1993 Mar;38(2):442-7.
Jones BM. et al. The in vivo effects of nonoxynol-9 contraception
on vaginal microbial flora and colonization with Escherichia coli
[letter; comment]. J Infect Dis 1993 Mar;167(3):777-8.
Chantler E. et al. Quantification of the in vitro activity of some
compounds with spermicidal activity. Contraception 1992
Dec;46(6):527-36.
Lesher JL Jr. What's in a name when efficacy isn't efficacious?
[letter; comment]. JAMA 1992 Dec 23-30;268(24):3434.
Chantler E. et al. Compatibility between the spermicide nonoxynol
9 and mid-cycle human cervical mucus. Contraception 1992
Sep;46(3):289-95.
Hermonat PL. et al. The spermicide nonoxynol-9 does not inactivate
papillomavirus. Sex Transm Dis 1992 Jul-Aug;19(4):203-5.
Gollub EL. et al. Nonoxynol-9 and the reduction of HIV transmission
in women [letter;comment]. AIDS 1992 Jun;6(6):599-601.
HOLES IN LATEX CONDOMS
These are answers from the Centers for Disease Control and
Prevention (CDC) to questions concerning reports of holes in latex
condoms.
1. There have been recent reports of naturally occurring holes in
latex that are big enough for HIV to pass through. Why does CDC
still recommend condoms to prevent HIV infection?
The reports of holes in latex appear to have originated from an
article in Science Magazine about latex gloves, not condoms. Holes
as large as 5 microns in diameter were evidently identified in
latex used in gloves. However, gloves are only dipped in latex once
when they are made, condoms are dipped twice in latex. Gloves are
allowed to fail the water leak test at a rate of 40 per thousand,
while condoms are only allowed 4 failures of the water leak test
per thousand condoms before the entire batch is rejected. While
holes large enough for HIV to pass through have been found in
natural membrane condoms, latex condoms do not allow the HIV to
pass through the condom unless the condom has been damaged or torn.
Used properly, latex condoms are effective in reducing the risk of
HIV infection.
(Centers for Disease Control and Prevention, HIV/AIDS Prevention
Training Bulletin, July 1, 1992.)
LEAKING THROUGH LATEX CONDOMS
These are answers from the Centers for Disease Control and
Prevention (CDC) to questions concerning the possibility of HIV
"leaking" through latex condoms.
1. Can HIV leak through microscopic holes in latex condoms?
The Food and Drug Administration (FDA) published a study in
the July-August 1992 issue of "STD" which examined whether
HIV-sized glass beads could be forced through latex condoms
under stressful laboratory conditions. These conditions
included higher concentrations of the "virus" (glass beads)
than in semen, a fluid that doesn't stick together as much as
semen, and forces that simulated 10 minutes of thrusting AFTER
ejaculation. Most latex condoms leaked absolutely nothing.
The worst condom found would still reduce exposure risk by
10,000-fold, i.e., only 1 HIV virus might "leak" through only
1 of every 90 condoms. Other tests have shown that under
"normal" conditions, HIV does not pass through a latex condom
that is not torn or broken.
2. How often do condoms break?
The studies do not agree on an exact rate of breakage. Many
studies of condom effectiveness have counted how often women
whose partners used condoms for birth control have gotten
pregnant. This "failure rate" includes cases where the couple
did not use a condom every time they had sex or used the
condoms incorrectly. Some studies have included the times the
condom was torn accidentally by the people using it. Studies
in other countries of breakage caused by defects in the condom
itself show a breakage rate ranging from 0% to 7%. In the
United States, most studies show the breakage rate is less
than 2 out of every 100 condoms, probably less than 1 out of
every 100.
(Centers for Disease Control and Prevention, HIV/AIDS Prevention
Training Bulletin, January 28, 1993.)
Latex Condom Study Flawed
[FDA has received] inquiries about a Mariposa Foundation study
that ranks the quality of various brands of condoms. Media reports
of the studies suggest that some brands leak and therefore may not
provide protection against AIDS and other sexually transmitted
diseases.
FDA believes that the study is flawed and therefore cannot be
relied upon to judge the relative quality of various brands of
condoms. The agency is concerned that some people may stop using
condoms as a result of this study.
FDA's position continues to be that latex condoms, if used
consistently and correctly, provide highly effective protection
against sexually transmitted diseases, including AIDS.
In 1988, the Mariposa Foundation, a private research group in
Topanga, Calif., conducted a laboratory study of 31 condom brands
to select condoms to be used in a clinical trial that would have
evaluated their protection against HIV, the virus that causes AIDS.
The clinical trial was never conducted.
One part of Mariposa's laboratory study measured the ability
of condoms to serve as a physical barrier to HIV. Test results
indicated that at least eight brands offered excellent protection
against the virus while at least five allowed some leakage.
FDA does not believe these test results should be relied on,
however, because the study was flawed for several reasons:
1. Too few batches were sampled to generalize about any brand
as a whole. Mariposa sampled three batches for most brands. A
sample of a few hundred condoms from a batch of a million might
provide adequate information about that particular batch if the
sample is taken in a scientifically random fashion, but it cannot
establish the performance of the entire brand. Environmental and
manufacturing conditions vary too much from one batch to another
to allow conclusions about the effiacy of a particular brand on the
basis of a small study sample.
FDA regularly inspects condom manufacturers and tests samples
of their products. When a faulty batch is found, the agency
prevents the sale of that batch. This applies both to domestic and
imported condoms.
2. Some brands include condoms made by different
manufacturers. Some batches from a single brand in the Mariposa
study could have come from a different manufacturer than the
majority of condoms sold under that brand name.
3. The Mariposa Foundation did not consider possible
deterioration due to improper storage conditions or age. Condoms
deteriorate rapidly when subjected to extremes of temperature, and
latex also deteriorates as it ages.
FDA is establishing expiration dating for all latex condoms.
Most domestic condoms already display an expiration date on the
packaging. New regulations will require expiration dates for both
domestic and imported latex condoms.
(FDA TALK PAPER. U.S. Department of Health and Human Services,
Public Health Service, Food and Drug Administration, T93-45,
October 12, 1993.)
[Editor's Note: For information about this study, contact the
Mariposa Education and Research Foundation, 3123 Schweitzer Drive,
Topanga, CA 90290. Telephone: 818-704-4812. See also: Voeller B.
Nelson J. Day C. Viral leakage risk differences in latex condoms.
AIDS Research and Human Retroviruses. 1994;10(6):701-10.]
The following is a question with an answer from the Centers for
Disease Control and Prevention concerning FDA regulations regarding
condoms.
"Is it true that FDA does not have specific regulations
regarding condoms? Do manufacturers set their own standards
(thickness, strength, size, etc.), and if they change
standards, they only have to register again with FDA?"
Since 1976, condoms have been regulated under the Medical
Device Amendments to the Food, Drug, and Cosmetic Act. Within the
FDA, the Center for Devices and Radiological Health is responsible
for assuring the safety and effectiveness of condoms as medical
devices.
While FDA performance standards have not been established for
condoms, FDA does recognize the American Society for Testing and
Materials (ASTM) Standard Specifications for Rubber Contraceptives
(condoms) D3492-83 as a basis for the condom definition. However,
if manufacturers choose to deviate from any of the ASTM specifica-
tions, they are required to submit a premarket notification to the
FDA at least 90 days before proposing to initiate commercial
distribution in the United States.
The FDA has also adapted its inspection sampling criteria to
conform with the ASTM Standard D3492-83 for latex condoms.
Beginning in the spring of 1987, FDA undertook an expanded program
to inspect latex condom manufacturers, repackagers, and importers
to evaluate their quality control and testing procedures. In
testing condoms, FDA uses a waterleak test in which a condom is
filled with 300 ml of water and checked for leaks. FDA criteria
and the industry-acceptable quality level for condoms specify that
in any given batch, the failure rate must not exceed four leaking
condoms per 1000 condoms.
(Centers for Disease Control and Prevention. Training Bulletin #37.
March 25, 1993.)
New Labeling to Provide Information
About Contraceptives and STDs
FDA has notified the manufacturers of certain contraceptives
that labeling accompanying their products must state that they do
not provide protection from sexually transmitted diseases (STDs),
including AIDS. The labeling changes are expected by the fall
[1993].
These products include oral contraceptives, intrauterine
devices, implantable and injectable contraceptives, and natural
membrane ("lambskin") condoms. FDA has instructed the manufacturers
of these products to change the labeling so that information about
the lack of protection against STDs is displayed prominently in
clear language for the consumer.
FDA is taking this action as part of ongoing education efforts
to reduce the risk of HIV infection and other sexually transmitted
diseases in sexually active individuals, particularly adolescents
and young adults, who may not know that products intended to
prevent pregnancy are not necessarily effective for other purposes.
Since 1987, FDA has strongly recommended that the labeling on
latex condoms provide information regarding their effectiveness in
preventing pregnancy and protecting users from STDs. Although the
labeling for natural membrane condoms has stated that the products
do not offer protection from STDs, such labeling has not been
required for most other contraceptives. The labeling varies
according to the type of contraceptive:
product is intended to prevent pregnancy. It does not protect
against HIV infection (AIDS) and other sexually transmitted
diseases.
intended to prevent pregnancy. It does not protect against HIV
infection (AIDS) and other sexually transmitted diseases. In order
to help reduce the risk of transmission of many STDs, including HIV
infection (AIDS), use a latex condom.
reduce the risk of transmission of HIV infection (AIDS) and many
other sexually transmitted diseases. [This message is to appear on
individual condom wrappers, as well as on the outer package.]
FDA, in conjunction with the National Institutes of Health
and the national Centers for Disease Control and Prevention, is
currently reviewing the scientific literature to determine whether
the labeling for other contraceptives, such as spermicides,
cervical caps, diaphragms, and the newly approved female condom,
should be changed as well.
(FDA BULLETIN, Department of Health and Human Services, Food and
Drug Administration, June 22, 1993.)
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
= U.S. Department of Veterans Affairs =
= AIDS Information Center =
= Michael Howe, MSLS =
= =
= VA Medical Center (142D) Voice: 415-221-4810 =
= 4150 Clement Street ext 3305 =
= San Francisco, CA 94121 FTS: 700-470-3305 =
= hivinfo@itsa.ucsf.edu FAX: 415-750-6919 =
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Ken Shirriff:
shirriff@eng.sun.com
This page:
http://www.righto.com/theories/condoms1.html
Copyright 2000 Ken Shirriff.
