DEPARTMENT
OF HEALTH & HUMAN SERVICES
Public Health Services
Centers for Disease Control
and Prevention (CDC)
Atlanta, Ga30333
August 4 2000
Dear Colleague:
 At the International AIDS
Conference held in Durban, South Africa, from July 9.14, 2000, researchers with the Joint
United Nations Program on AIDS (UNAIDS) presented results of an important study about HIV
prevention in woman. They studied a product widely used in spermicides, nonoxynol-9 (N-
9), to determine if it would be Effective in preventing HIV transmission. Products
designed to provide a chemical barrier to HIV and STD transmission are called
microbicides. This notice summarizes the study results and some implications for use of
this product in prevention programs.
From 1996 until May 2000, UNAIDS sponsored a study of the effectiveness of a gel which
contained 52.5 milligrams of N-9 (called COL'1492 in the trial and Advantag-S in the
United States), compared to an inactive placebo gel. The study was conducted in several
locations in Africa. Nearly 1,000 HIV-negative commercial sex workers were enrolled in the
trial, and all women were counseled to use condoms consistently and correctly. In addition
to condom use, the women were asked to use a vaginal gel each time they had intercourse.
Half of the women were provided a placebo gel and half of the women received an N-9
spermicide gel. None of the woman, or the researchers, knew which product each woman
received, and all of the women were informed of the possible risks, benefits, arid
unknowns involved in the spermicide study.
At the end of the trial, researchers found that the women who used the spermicide N-9 gel
had become infected with HIV at about a 50% higher rate than women who used the placebo
gel. Further, the more frequently women used only N-9 spermicide gel (without a condom) to
protect themselves, the higher their risk of becoming infected. Simply stated, the
spermicide N-9 did not protect against HIV infection and may have caused more
transmission. Women who used the spermicide N-9 also had more vaginal lesions, which might
have facilitated HIV transmission.
This study was conducted among women at very high risk commercial sex workers who used a
great deal of the product on a frequent basis. The adverse effects might not be seen at
the same level among women who are using spermicides with N.9 less frequently or in
different formulations. However, given that the spermicide Nonoxynol-9 has now been proven
ineffective against HIV transmission, the possibility of risk, with no benefit, indicates
that Nonoxynol-9 should not be recommended as an effective means of HIV prevention.
With the release of these data, the scientific evidence on spermicide Nonoxynol-9 as an
HIV prevention strategy is now conclusive and significant. As a result prevention
guidelines must be re-evaluated UNAIDS and CDC will be holding consultations over the next
few months to consider official revisions to public health guidelines for the use of N-9
for HIV prevention and for pregnancy prevention in populations at high risk for HIV. In
the interim, those findings have several immediate implications.
First, any community delivering hierarchical prevention messages that counsel individuals
who can't use a condom to consider spermicides with N-9 for HIV prevention should
immediately revise these messages. This study suggests that the use of spermicide N-9 for
HIV prevention may he harmful. Second, anyone currently using N- 9 as a microbicide to
protect themselves from HIV transmission during anal intercourse should be informed of the
ineffectiveness of this agent and warned of the potential risk of this practice.
CDC has never
recommended the spermicide N-9 alone for HIV prevention, but current recommendations do
emphasize the consistent and correct use of condoms, with or without a spermicide. While
the level of N-9 used as a lubricant in condoms is much lower than the level found to be
harmful in this study, CDC will re-evaluate this guidance as part of the upcoming
consultation. In the interim, while N-9 spermicide will not offer any additional
protection against HIV, a condom lubricated with Nonoxynol - 9 is clearly better than
using no condom at all. The protection provided by the condom against HIV far outweighs
the potential risk of N-9. If given the choice, condoms without N-9 spermicide may be a
better option for HIV prevention.
From a research perspective, these findings point to the need for accelerated efforts to
identify a safe and effective microbicide. Of the more than 7,000 new HIV infections
occurring in the world each day, about 90% are the result of heterosexual transmission. In
addition, more than 330 million new cases of other STDs, such as gonorrhea, chlamydia, and
syphilis, occur each year.
For those who are unable to access condoms or to negotiate their use, there is an urgent
need to identify an effective alternative to prevent HIV and STD transmission. Moving
forward with the evaluation of microbicide candidates, which are not likely to cause the
same negative effect seen with Nonoxynol 9 spermicide, should be a public health priority.
We appreciate any assistance you can provide in disseminating this critical public health
information and will keep you informed as the consultations are completed
Sincerely,
Helene D. Gayle, M.D., M.P.H.
Director, National Center for HIV, STD, and TB Prevention
Centers for Disease Control and Prevention
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