The Role of STD
Detection and Treatment
in HIV Prevention

Testing and treatment of sexually transmitted
diseases (STDs) can be an effective tool in
preventing the spread of HIV, the virus that
causes AIDS. An understanding of the relation-
ship between STDs and HIV infection can help in
the development of effective HIV prevention
Pucatams or persons with high-risk sexual
ehaviors.

Evidence from intervention studies indicates that
detecting and treating STDs can substantially
reduce HIV transmission at the individual and
community levels.

STD treatment reduces an individual's ability
to transmit HIV. Studies have shown that
treating STDs in HIV-infected individuals
decreases both the amount of HIV they shed
and how often they shed the virus (Fleming,
Wasserheit, 1999).

STDstand ivyinfection?)

Individuals who are infected with STDs are at
least two to five times more likely than
uninfected individuals to acquire HIV if they are
exposed to the virus through sexual contact. In
addition, if an HIV-infected individual is also
infected with another STD, that person is more
likely to transmit HIV through sexual contact than
other HIV-infected persons (Wasserheit, 1992).

STD treatment reduces the spread of HIV
infection in communities. Two community-
level, randomized trials have examined the
role of STD treatment in HIV transmission.
Together, their results have begun to clarify
conditions under which STD treatment is
likely to be most successful in reducing HIV
transmission. First, continuous interventions
to improve access to effective STD treatment
services is likely to be more effective in
reducing HIV transmission than intermittent
interventions through strategies such as
periodic mass treatment. Second, STD
treatment is likely to be most effective in
reducing HIV transmission where STD rates
are high and the heterosexual HIV epidemic
is young. Third, treatment of symptomatic

There is substantial biological evidence demon-
strating that the presence of other STDs
increases the likelihood of both transmitting and
acquiring HIV (Fleming, Wasserheit, 1999).

= Increased suscep HPI: STDs _ probably
increase susceptibility to HIV infection by

two mechanisms. Genital ulcers (e.g., syphi-
lis, herpes, or chancroid) result in breaks in
the genital tract lining or skin. These breaks
create a portal of entry for HIV. Non-
ulcerative STDs (e.g., chlamydia, gonorrhea,
and trichomoniasis) increase the concentra-
tion of cells in genital secretions that can
serve as targets for HIV (e.g., CD4+ cells).

secretions. For example, men who are
infected with both gonorrhea and HIV are

more than twice as likely to shed HIV in their
genital secretions than are those who are
infected only with HIV. Moreover, the median
concentration of HIV in semen is as much as
10 times higher in men who are infected with
both gonorrhea and HIV than in men infected
only with HIV.

STDs may be particularly important.

The first community trial, conducted in a
rural area of Tanzania, demonstrated a
decrease of about 40% in new, heterosexu-
ally transmitted HIV infections in communi-
ties with continuous access to improved
treatment of symptomatic STDs, as com-
pared to communities with minimal STD

Bincieaced!) Infectiousness. ‘Studies uihave services, where incidence remained about the
shown that when HIV-infected individuals same (Grosskurth, Mosha, Todd, et al.,
are also infected with other STDs, they are 1995). However, in the second trial con-
more likely to have HIV in their genital ducted in Uganda, a reduction in HIV

transmission was not demonstrated when the
STD control approach was community-wide
mass treatment administered to everyone
every 10 months in the absence of regular
access to improved STD services (Wawer, et
al., 1999).



Strong STD prevention, testing, and treatment
can play a vital role in comprehensive programs
to prevent sexual transmission of HIV. Further-
more, STD trends can offer important insights
into where the HIV epidemic may grow, making
STD surveillance data helpful in forecasting
where HIV rates are likely to increase. Better
linkages are needed between HIV and STD
peewention efforts nationwide in order to control
oth epidemics.

In the context of persistently high prevalence of
STDs in many parts of the United States and with
emerging evidence that the U.S, HIV epidemic
increasingly is affecting ee ee with the
highest rates of curable STDs, CDC's Advisor’
Committee on HIV and STD Prevention (ACHSP.
has recommended the following:

® Early detection and treatment of curable STDs
should become a major, explicit component of
comprehensive HIV prevention programs at
national, state, and local levels;

"In areas where STDs that facilitate HIV
transmission are prevalent, screening and
treatment programs should be expanded;

® HIV and STD prevention programs in the
United States, together with private and
public sector partners, should take joint
responsibility for implementing these strate-
gies.

The ACHSP also notes that early detection and
treatment of STDs should be only one compo-
nent of a comprehensive HIV prevention
program, which also must include a range of

social, behavioral, and biomedical interventions.

Where"canl getimoreinformation?

Division of STD Prevention (DSTDP)
Centers for Disease Control and Prevention
http://www.cdc.gov/std

Order Publications Online at
www.cdc.gov/std/pubs/

STD information and referrals to STD Clinics
CDC-INFO

1-800-CDC-INFO (Cece Io)

TTY: 1-888-232-6348

In English, en Espafiol

ieee ete Prevention Information Network

.O. Box 6003

Rockville, MD 20849-6003
1-800-458-5231
1-888-282-7681 Fax
1-800-243-7012 TTY
E-mail: info@cdcnpin.org
www.cdenpin.org

American Social Health Association (ASHA)
P. O. Box 13827

Research yangle Park, NC 27709-3827
1-800-783-9877

www.ashastd.org

Printable versions of this and other STD fact sheets are available at:
http://www.cdc.gov/std/healthcomm/fact_sheets.htm

Fact Sheet