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. Chlamydia trachomatis and Neisseria gonorrhoeae are the agents of the two most prevalent bacterial sexually transmitted infections (STIs) reported to the Centers for Disease Control and Prevention (CDC), accounting for Ͼ1.6 million reported infections in the United States in 2010 (1). The CDC estimates that STIs cost the health care system $1.5 billion annually. Since these infections, especially chlamydia, are most often asymptomatic, the CDC recommends yearly screening for chlamydia in all sexually active women aged 16 to 25 years. Further, since coinfections are common, most diagnostic test platforms assay for both organisms. Nucleic acid amplification tests (NAATs) are now recommended by the CDC (2) as the tests of choice; however, current NAATs are classified as being of high or moderate complexity and might take 1 to 2 days for results to become available. New assays and new platforms that provide results at the time of patient visits are urgently needed, since many patients do not return for their results when laboratory-based tests that require several days for their results are performed (3, 4).The Cepheid GeneXpert CT/NG (Xpert) assay is a rapid (Ͻ2 h to results) NAAT assay that can be performed in on-site laboratories. The assay detects the DNA of C. trachomatis and N. gonorrhoeae from endocervical, vaginal, and urine specimens of females, as well as from urine specimens of males, from both symptomatic and asymptomatic individuals. The Xpert test is performed using a modular cartridge-based platform for testing each specimen by nucleic acid amplification, and it can process from 1 to 96 specimens in Ͻ2 h with easy-to-use cartridges that minimize processing steps and contamination. This study compares the clinical performance (as measured by sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV]) of the Xpert assay to the patient infection status (PIS)...

The performance of the Becton Dickinson BDProbe Tec ET System Chlamydia trachomatis and Neisseria gonorrhoeae Amplified DNA Assays (BD Biosciences, Sparks, Md.) was evaluated in a multicenter study. Specimens were collected from 2,109 men and women, with or without symptoms, attending sexually transmitted disease, family planning, and obstetrics and gynecology clinics. Both swab and urine samples were collected, and the results obtained from 4,131 specimens were compared to those from culture and the LCx nucleic acid amplification test (Abbott Industries, Abbott Park, Ill.). PCR and cytospin of the culture transport medium with chlamydia direct fluorescent antibody staining were used to adjudicate chlamydia culture-negative results. Sensitivity and specificity were calculated both with and without use of the amplification control (AC), with little apparent difference in the results. Without the AC result, sensitivity for C. trachomatis and N. gonorrhoeae were 92.8 and 96.6%, respectively, for cervical swabs and 80.5 and 84.9% for urine from women. C. trachomatis and N. gonorrhoeae sensitivities were 92.5 and 98.5%, respectively, for male urethral swabs and 93.1 and 97.9% for urine from men. This amplified DNA system for simultaneous detection of chlamydial and gonococcal infections demonstrated superior sensitivity compared to chlamydia culture and has performance characteristics comparable to those of other commercially available nucleic acid-based assays for these organisms.

IntroductionLong-term natural history cohorts of HIV-1 in the absence of treatment provide the best measure of virulence by different viral subtypes.MethodsNewly HIV infected Ugandan and Zimbabwean women (N = 303) were recruited and monitored for clinical, social, behavioral, immunological and viral parameters for 3 to 9.5 years.ResultsUgandan and Zimbabwean women infected with HIV-1 subtype C had 2.5-fold slower rates of CD4 T-cell declines and higher frequencies of long-term non-progression than those infected with subtype A or D (GEE model, P < 0.001), a difference not associated with any other clinical parameters. Relative replicative fitness and entry efficiency of HIV-1 variants directly correlated with virulence in the patients, subtype D > A > C (P < 0.001, ANOVA).DiscussionHIV-1 subtype C was less virulent than either A or D in humans; the latter being the most virulent. Longer periods of asymptomatic HIV-1 subtype C could explain the continued expansion and dominance of subtype C in the global epidemic.

NAATs were performed on FCU, urethral, cervical, self-and clinician-collected VS. Sensitivity was compared to isolation using cervical and urethral swabs. Agreement of NAAT results between VS and cervical swabs or FCU was calculated. Specimens from 2,517 15-to 25-year-old asymptomatic women attending clinics at nine different centers were evaluated. Results with self-and clinician-collected VS were equivalent and were at least as good as results with FCU and cervical swabs. Across all sites, summary specificities for all specimens were >99%. Among culture-positive women, NAAT sensitivity with VS (93%) was as high as or higher than NAAT sensitivity with cervical swabs (91%) or FCU (80.6%) or culture of cervical swabs (83.5%). VS are appropriate specimens for diagnosing chlamydial genital tract infection by NAATs. That patients can efficiently collect them offers important benefits for screening programs. It would be beneficial for public health programs if the NAAT manufacturers sought FDA clearance for this specimen.

Findings of this study revealed differences in the distribution of chronic ankle instability that warrant further study.