Reexamining the prevalence of Chlamydia trachomatis infection among gay men with urethritis: implications for STD policy and HIV prevention activities.

BACKGROUND: Evidence of an STD-HIV interaction and the availability of noninvasive urine-based screening tests have resulted in an increased focus on chlamydial infections in men. GOAL: To evaluate the prevalence of chlamydial infections among men with urethritis at the San Francisco City Clinic (SFCC). STUDY DESIGN: In 1997, male SFCC patients diagnosed with urethritis were tested for chlamydia using urine-based ligase chain reaction and for gonorrhea using urethral culture. RESULTS: Gonorrhea was identified in 45% of men who have sex with men (MSM) versus 26% of men who have sex with women (MSW). Among men with gonorrhea, chlamydia coinfection was found among 15.2% of MSM and 8.4% of MSW. Among men with nongonococcal urethritis, 18% and 20% of MSM and MSW had chlamydial infection, respectively. Young age was associated with chlamydial infection in MSM. CONCLUSION: After a period of low chlamydial infection rates in MSM during the pre-AIDS era, infection rates are increasing among this population. SFCC's revised clinical practice guidelines include chlamydia testing of MSM with urethritis.

Evaluation of chlamydia and gonorrhea screening criteria: San Francisco sexually transmitted disease clinic: 1997 to 1998.

BACKGROUND AND OBJECTIVES: The advent of more sensitive diagnostic testing technologies and competition in public healthcare spending have resulted in a reevaluation of sexually transmitted disease (STD) screening practices in an attempt to target populations at greatest risk. Screening among populations with a < 2% prevalence of chlamydia and a < 1% prevalence of gonorrhea may not be cost-effective. GOAL: To identify subpopulations with a low prevalence of chlamydia or gonorrhea. STUDY DESIGN: The prevalence of genital chlamydia and gonorrhea among asymptomatic STD patients screened from 1997 to 1998 at San Francisco City Clinic was stratified by demographic and behavioral risk factors. RESULTS: The prevalence of chlamydia and gonorrhea was 3.4% and 1.1% among asymptomatic women and 4.0% and 1.0% among asymptomatic men, respectively. Two low-prevalence subpopulations identified among asymptomatic patients were women older than 29 years (chlamydia, 1.2%) and men who have sex with women (gonorrhea, 0.8%). CONCLUSIONS: These data identified low-prevalence subpopulations among asymptomatic STD patients. As a result, the STD screening criteria at San Francisco City Clinic were changed accordingly.

Comparisons of cost and accuracy of DNA probe test and culture for the detection of Neisseria gonorrhoeae in patients attending public sexually transmitted disease clinics in Los Angeles County.

BACKGROUND: Strict handling and transport requirements for the successful use of culture in the detection of Neisseria gonorrhoeae warrant investigation of accurate and cost-effective test alternatives such as the Gen-Probe PACE 2 DNA probe assay (Gen-Probe, Inc., San Diego, CA). STUDY DESIGN: The Gen-Probe PACE 2 DNA probe assay for N. gonorrhoeae was compared with conventional culture methods in the principal Los Angeles County (LAC) Department of Health Services (DHS) Public Health Laboratory and three of its branch laboratories. Urethral and endocervical samples were collected from 1,566 patients (921 males; 645 females) attending six LAC DHS sexually transmitted disease clinics. Cost analysis was performed comparing material and labor costs of the two test methods. RESULTS: The overall prevalence based on culture was 11.8% (15.7% for males; 6.4% for females). Nine samples were culture positive, Gen-Probe negative and four samples were culture negative, Gen-Probe positive and remained discordant after discrepant analysis. The sensitivity and specificity were 94.6% and 99.7%, respectively, for the PACE 2 assay compared with culture. The positive and negative predictive values were 97.8% and 99.3%, respectively. No statistically significant difference was found between the two tests. A cost analysis found an average cost of $3.11/test for culture and $3.85/test for PACE 2, given the approximate 12% disease prevalence in this population. CONCLUSIONS: Gen-Probe's PACE 2 assay may provide an acceptable, cost-effective alternative to culture, especially among high-risk males.