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Workshop Summary:
Scientific Evidence on Condom Effectiveness
for Sexually Transmitted Disease (STD) Prevention
EXECUTIVE SUMMARY
Background
Sexually transmitted
diseases (STDs), including HIV, are common, important, and
preventable causes of morbidity, mortality, disability, lost-productivity,
and health care costs. In the United States, more than 65
million individuals are living with an STD, the majority
of which are incurable viral infections. Approximately 15 million new sexually
transmitted infections occur annually in the U.S. In the United States,
approximately 493,000 individuals have died from AIDS,
and 800,000-900,000 people are living with HIV disease.
Many sexually transmitted infections can cause adverse pregnancy
outcomes including miscarriages, stillbirths, intrauterine growth
restriction and perinatal (mother-to-infant) infections.
Some STDs can cause infertility or lead to ectopic
pregnancy among women and one, the human papillomavirus, can cause cervical and
anogenital cancer. Furthermore, other STDs facilitate HIV transmission.
The Problem and the
Process
Primary prevention of
STD infection is an important health priority. Unfortunately there
are no STD vaccines, except for hepatitis B vaccine, and topical
microbicides to prevent STDs are not available. Beyond
mutual lifelong monogamy among uninfected couples,
condom-use is the only method for reducing the risk of HIV infection and STDs
available to sexually active individuals.
Recently, a number of
Federal agencies sponsored a workshop to answer the following
question: "What is the scientific evidence on the effectiveness of latex
male condom-use to prevent STD transmission during
vaginal intercourse?" This workshop was attended by 180
persons, and the data from numerous peer-reviewed published studies were
discussed. Following the workshop, a panel of 28 experts worked to
develop this report. The sessions included review of
published information on the properties and user patterns
of the male latex condoms for vaginal intercourse and included data from
studies on pregnancy prevention. Focused research studies have documented
the high effectiveness of condoms for prevention of
pregnancy. The data associated with condom use in eight
specific STDs were considered in detail, including HIV infection,
gonorrhea, chlamydial infection (including gonococcal and chlamydial
pelvic inflammatory disease), syphilis, chancroid,
trichomoniasis, genital herpes, and genital HPV infection
and associated diseases (i.e. cervical dysplasia, cervical cancer and
genital warts). The meeting was not intended to
make public health policy recommendations regarding the
role of condoms in HIV/STD prevention policy and programs.
Assessment of the Data
In general, the Panel
found the published epidemiology literature to be inadequate to
definitively answer the question posed to the workshop participants. Most
studies reviewed did not employ a prospective design,
which is the optimal method to assess the effectiveness
of condoms in preventing infection.
Conclusions on STDs
Transmitted by Genital Secretions
The published data
documenting effectiveness of the male condom were strongest for
HIV. The Panel concluded that, based on a meta-analysis of published
studies "always" users of the male condom significantly
reduced the risk of HIV infection in men and women. These
data provided strong evidence for the effectiveness of condoms in
preventing HIV transmission in both men and women who engage in vaginal
intercourse .
The Panel also concluded that the consistency of findings across four
epidemiological studies of gonorrhea indicated that the
latex male condom could reduce the risk of gonorrhea for
men.
The strongest
evidence for potential effectiveness of condoms on other STDs
transmitted by genital secretions (i.e. gonorrhea in women, chlamydial
infection and trichomoniasis) was the laboratory-based
studies on the properties of the male latex condom and
the strength of the evidence for condom use reducing the risk of HIV
transmission in men and women and gonorrhea in men. The Panel concluded,
however, that because of limitations in study designs
there was insufficient evidence from the epidemiological
studies on these diseases to draw definite conclusions about the
effectiveness of the latex male condom in reducing the transmission of
these diseases.
Conclusions on Genital
Ulcer Diseases
The Panel agreed that
the published epidemiologic data were insufficient to draw
meaningful conclusions about the effectiveness of the latex male condom
to reduce the risk of transmission of genital ulcer
diseases (genital herpes, syphilis and chancroid).
Conclusions on HPV
For HPV, the Panel
concluded that there was no epidemiologic evidence that condom
use reduced the risk of HPV infection, but study results did suggest that
condom use might afford some protection in reducing the
risk of HPV-associated diseases, including warts in men
and cervical neoplasia in women.
Summary
The Panel stressed
that the absence of definitive conclusions reflected inadequacies of
the evidence available and should not be interpreted as proof of the
adequacy or inadequacy of the condom to reduce the risk
of STDs other than HIV transmission in men and women and
gonorrhea in men. To definitely answer the remaining questions
about condom effectiveness for preventing STD infections will require
well-designed and ethically sound clinical studies.
(ver relatório
condomreport.pdf)

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