Journal of Acquired Immune Deficiency Syndromes (08.15.03)
CDC recommends STD screening among HIV-positive patients. STDs
facilitate the spread of HIV, so the diagnosis and treatment
of curable STDs in HIV-infected persons can help prevent the
spread of HIV to partners even when infected persons continue
unprotected sex. However, according to the authors, such
screening is not widely practiced in US HIV clinics.
To examine the potential benefits of an STD screening program
in a public HIV clinic in New Orleans, the researchers
analyzed the results of a urine-based screening for gonorrhea
and chlamydia among HIV-positive patients and compared the
positivity rates to the prevalence in the local community's
general population. To project the potential value of the
screening, the investigators estimated the number of potential
HIV infections among sex partners that treatment of gonorrhea
and chlamydia infections prevented.
For the study period from October 1998-June 2001, researchers
found 1.7 percent of those tested for gonorrhea (46/2,629) to
have it, and 2.1 percent (56/2,629) of those tested had
chlamydia. Test positivity did not vary greatly by race or
sex, although African-American women had higher rates of
chlamydia (3.5 percent) than white women (1.9 percent),
African- American men (1.2 percent) or white men (1.2
percent). But test positivity declined sharply with age: the
percentage of patients with gonorrhea fell from 4.8 percent
among 15- to 19-year-olds to 1.2 percent among those older
than 35. Chlamydia rates fell from 9.5 percent among 15- to
19-year-olds to 0.9 percent among persons older than 35.
Still, all age groups tested showed some infections.
Among 18- to 29-year-olds, test positivity for gonorrhea was
similar in the HIV clinic to positivity for members of the
sociodemographically similar community (3.1 percent versus 2.4
percent). Test positivity for chlamydia in that age cohort was
lower among HIV patients (5.4 percent versus 10.5 percent).
Based on a previously developed mathematical model, the
authors estimated that treatment of all 46 gonorrhea and 56
chlamydia infections in the HIV clinic may have averted 9 HIV
infections among sex partners and saved a great deal more in
future medical costs than the cost of the screening.
The authors pointed out that implementation of the STD
screening program demonstrates the feasibility of routine
screening in HIV clinics. That positivity rates approximated
those of a sociodemographically matched general population
"suggests that HIV-infected persons in care continue to
practice high-risk sexual behavior, perhaps at about the same
level as the general population," the investigators
speculated. The study notes that the mathematical model
suggests the even with a relatively low prevalence of
gonorrhea and chlamydia among the HIV-infected, screening and
treatment of such infections in HIV clinics may prevent a
large enough number of HIV infections to be worthwhile.
"In conclusion," the authors noted, "this study supports the
CDC recommendation that screening for gonorrhea and chlamydia
infection should be established in HIV clinics as part of
routine care, at least in geographic areas with higher rates
of these STDs. Patients in these clinics found to have these
or other STDs can be intensively counseled to reduce risky
sexual behavior, their curable STDs can be easily treated, and
confidential partner notification procedures initiated. Thus
STD screening can initiate a series of actions with the
potential to prevent HIV transmission to others."