Mathilda Barnes

Internet-based screening for chlamydia trachomatis to reach nonclinic populations with mailed self-administered vaginal swabs

Background: Testing for Chlamydia trachomatis by nucleic acid amplification tests (NAATs) using self-collected vaginal swabs (VS) is acceptable and accurate. The objectives were to implement an educational Internet-based program for women to facilitate home screening, to determine whether women would request and use self-collected VS kits, to determine associated risk factors for infection, and to determine satisfaction with the process. Methods: The website, www.iwantthekit.org, was designed to encourage women ≥14 years to obtain home-sampling kits. Kits could be obtained in the community, requested by Internet/e-mail, or telephone. Users mailed the self-collected VS to the laboratory. Swabs were tested by 3 NAAT assays. Respondents called for results. Results: Forty-one of 400 (10.3%) women were chlamydia positive; 95.1% were treated. Questionnaires indicated 89.5% preferred self-collection, 93.5% rated collection easy/very easy, and 86.3% would use the Internet program again. Black race and age <25 years were associated independently with being chlamydia positive, while use of birth control and nonconsensual sex were protective. Thirty-six of 41 (87.8%) positive samples were positive by all 3 NAATs, 5/41 (12.2%) were positive by only 2 NAATs, and none were positive by only 1 NAAT. The Internet/e-mail request method was better than the community pick-up approach because 97.2% of kit requests were e-mailed and 87.5% of kits returned for testing were e-mail requested. Conclusions: Women will use the Internet to request and use home-sampling kits for chlamydia. NAAT testing performed well on dry-transported VS. High prevalence was detected and questionnaires indicated high-risk sexual behavior.

Performance of the Cepheid CT/NG Xpert Rapid PCR Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

ABSTRACT Tests for Chlamydia trachomatis and Neisseria gonorrhoeae, which can provide results rapidly to guide therapeutic decision-making, offer patient care advantages over laboratory-based tests that require several days to provide results. We compared results from the Cepheid GeneXpert CT/NG (Xpert) assay to results from two currently approved nucleic acid amplification assays in 1,722 female and 1,387 male volunteers. Results for chlamydia in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 97.4%, 98.7%, and 97.6%, respectively, and for urine samples from males, a sensitivity of 97.5%, with all specificity estimates being ≥99.4%. Results for gonorrhea in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 100.0%, 100.0%, and 95.6%, respectively, and for urine samples from males, a sensitivity of 98.0%, with all estimates of specificity being ≥99.8%. These results indicate that this short-turnaround-time test can be used to accurately test patients and to possibly do so at the site of care, thus potentially improving chlamydia and gonorrhea control efforts.

Internet-based Screening for Sexually Transmitted Infections To Reach Nonclinic Populations in the Community: Risk Factors for Infection in Men

Background: Internet-based screening for sexually transmitted infections (STIs) has been acceptable to women, and can reach high-risk populations. No prior published data describe internet-based screening for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis in men. We studied whether internet-based screening was acceptable and reached a high-risk population, and what risk factors were associated with STI positivity. Methods: The website, www.iwantthekit.org, encouraged men ≥14 years of age to request a home self-sampling kit and a questionnaire on risk factors and acceptability of internet-based screening. Penile swabs and urine samples were tested for C. trachomatis, N. gonorrhoeae, and T. vaginalis using a nucleic acid amplification test. Risk factors and acceptability were examined using chi squared tests and logistic regression. Results: Of 501 samples received for testing, 106 (21%) were positive for at least one STI, 64 (13%) for chlamydia, 4 (1%) for gonorrhea, and 49 (10%) for trichomonas. In multivariable analyses, age, race, household income, and frequency of condom use were independently associated with infection with at least one STI. Of the total respondents, 34% had a prior STI; 29% reported having a partner with an STI, but only 13% reported always using a condom. Among the men who participated in this study, 77% preferred a self-administered specimen versus attending a clinic, 89% reported that swab use was easy, and 89% reported that they would use internet-based screening again. Conclusions: Men who accessed internet-based screening had known risk factors for STIs and had a high prevalence of infection. Internet-based screening was acceptable and could reach these high-risk men who might not otherwise be reached through traditional means.

Can E-Technology Through the Internet be Used as a New Tool to Address the Chlamydia trachomatis Epidemic by Home Sampling and Vaginal Swabs?

The Internet provides patients, as well as clinicians with immediate, confidential access to information about sexually transmitted diseases (STDs).1,2 Young individuals are avid users of the Internet and usage has been considered to be a risk factor for STDs.3–7 Data indicate that there are 246,402,574 North American Internet users.8

Comparative effectiveness of a rapid point-of-care test for detection of Chlamydia trachomatis among women in a clinical setting

Objectives To compare the effectiveness and cost-effectiveness of a promising new point-of-care (POC) chlamydia test with traditional nucleic acid amplification testing (NAAT), and to determine the characteristics that would make a POC test most cost-effective. Methods A decision tree was constructed to model chlamydia screening visits to a sexually transmitted disease clinic by a hypothetical cohort of 10 000 women. The model incorporated programmatic screening costs, treatment costs and medical costs averted through prevention of pelvic inflammatory disease (PID) and its sequelae. Parameter values and costs were estimated for each node in the decision tree based on primary data, published data and unpublished health data. Results For the base-case scenario (POC sensitivity 92.9%; 47.5% of women willing to wait 40 min for test results; test cost

Cost-effectiveness of screening strategies for chlamydia trachomatis using cervical swabs, urine, and self-obtained vaginal swabs in a sexually transmitted disease clinic setting

33.48), POC was estimated to save US

Perceptions of an ideal point-of-care test for sexually transmitted infections - A qualitative study of focus group discussions with medical providers

5050 for each case of PID averted compared with NAAT. One-way sensitivity analyses indicated that POC would dominate NAAT if the POC test cost is <US

Detection of Trichomonas vaginalis DNA by Use of Self-Obtained Vaginal Swabs with the BD ProbeTec Qx Assay on the BD Viper System

41.52 or if POC sensitivity is ≥87.1%. In a probabilistic sensitivity analysis (Monte Carlo simulations, 10 000 iterations), 10.8% of iterations indicated that the POC strategy dominated the NAAT strategy. The mean incremental cost-effectiveness ratio indicated that the POC strategy would save US

Trichomonas vaginalis infection in women who submit self-obtained vaginal samples after Internet recruitment

28 in total, and avert 14 PID cases. Conclusions A promising new chlamydia POC test is likely to be cost-effective compared with traditional NAAT. The POC test sensitivity, cost and proportion of women willing to wait for the POC test result are key elements to determining the cost-effectiveness of any new POC test strategy.

Trichomonas vaginalis infection in men who submit self-collected penile swabs after internet recruitment

Background: We evaluated the cost-effectiveness of Chlamydia screening strategies that use different methods of specimen collection: cervical swabs, urines, and self-obtained vaginal swabs. Methods: A decision analysis was modeled for a hypothetical cohort of 10,000 per year of women attending sexually transmitted disease (STD) clinics. Incremental cost-effectiveness of 4 screening strategies were compared: 1) Endocervical DNA probe test (PACE2, Gen-Probe), 2) Endocervical AC2 (Aptima Combo 2, Gen-Probe), 3) Self-Obtained Vaginal AC2, and 4) Urine AC2. Sensitivities of the vaginal, urine, and cervical AC2 tests were derived from 324 women attending STD clinics. The primary outcome was cases of pelvic inflammatory disease prevented. The model incorporated programmatic screening and treatment costs and medical cost savings from sequelae prevented. Results: Chlamydia prevalence in the sampled population was 11.1%. Sensitivities of vaginal, urine, and cervical AC2 were 97.2%, 91.7%, and 91.7%, respectively. The sensitivity of the DNA probe was derived from the literature and estimated at 68.8%. The self-obtained vaginal AC2 strategy was the least expensive and the most cost-effective, preventing 17 more cases of pelvic inflammatory disease than the next least expensive strategy. Conclusions: Use of a vaginal swab to detect Chlamydia in this STD clinic population was cost-saving and cost-effective.