The microbicide tenofovir does not inhibit nucleic acid amplification tests for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine samples

The potential inhibitory effects of tenofovir and a placebo were examined using the Becton Dickinson ProbeTec, Gen-Probe Aptima Combo 2, and Roche Amplicor tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae. Concentrations of 5% to 0% of tenofovir and the placebo were added to dilutions of C. trachomatis and N. gonorrhoeae. No appreciable inhibition was observed.     

Impact of the New Abbott mPLUS Feature on Clinical Laboratory Efficiencies of Abbott RealTime Assays for Detection of HIV-1, Hepatitis C Virus,Hepatitis B Virus,Chlamydia trachomatis,and Neisseria gonorrhoeae

Diagnostic laboratories are under increasing pressure to improve and expand their services. Greater flexibility in sample processing is a critical factor that can improve the time to results while reducing reagent waste, making laboratories more efficient and cost-effective. The introduction of the Abbott mPLUS feature, with the capacity for extended use of amplification reagents, significantly increases the flexibility of the m2000 platform and enables laboratories to customize their workflows based on sample arrival patterns. The flexibility in sample batch size offered by mPLUS enables significant reductions in processing times. For hepatitis B virus tests, a reduction in sample turnaround times of up to 30% (105 min) was observed for batches of 12 samples compared with those for batches of 24 samples; for Chlamydia trachomatis/Neisseria gonorrhoeae tests, the ability to run batches of 24 samples reduced the turnaround time by 83% (54 min) compared with that for batches of 48 samples. Excellent correlations between mPLUS and m2000 standard condition results were observed for all RealTime viral load assays evaluated in this study, with correlation r values of 0.998 for all assays tested. For the qualitative RealTime C. trachomatis/N. gonorrhoeae assay, the overall agreements between the two conditions tested were >98% for C. trachomatis and 100% for N. gonorrhoeae. Comparable precision results were observed for the two conditions tested for all RealTime assays. The enhanced mPLUS capability provides clinical laboratories with increased efficiencies to meet increasingly stringent turnaround time requirements without increased costs associated with discarding partially used amplification reagents.     

Performance of Three Nucleic Acid Amplification Tests for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by Use of Self-Collected Vaginal Swabs Obtained via an Internet-Based Screening Program

Use of self-obtained vaginal specimens processed by nucleic acid amplification tests (NAATs) has significantly increased the utilization of nontraditional locations for Chlamydia trachomatis and Neisseria gonorrhoeae screening programs. One important emerging source of such venues includes home-based self-sampling kits available via the Internet. The objective of our study was to evaluate the performance of three commercially available NAATs (Becton-Dickinson ProbeTec SDA, Gen-Probe Aptima Combo2 TMA, and Roche Amplicor PCR) for detection of C. trachomatis and N. gonorrhoeae in vaginal samples obtained via an Internet-based screening program. From July 2004 to August 2005, 500 self-collected vaginal swabs were tested for C. trachomatis and N. gonorrhoeae by using all three NAATs. Another 500 samples were collected between August 2005 and November 2007 and tested by ProbeTec and Combo2; PCR testing was discontinued due to low specificity for N. gonorrhoeae. All tests were conducted according to the manufacturers'' procedures; the “gold standard” for an infected C. trachomatis or N. gonorrhoeae patient was defined as ≥2 positive NAAT results. Of the first 500 swabs submitted, 46 were C. trachomatis infected (9.2%) and 5 were N. gonorrhoeae infected (1.0%), and 3 of these were coinfected (0.6%). All C. trachomatis and N. gonorrhoeae Combo2-positive/ProbeTec-negative samples were confirmed as true positives by an alternative NAAT. For C. trachomatis, ProbeTec, Combo2, and PCR had sensitivities of 82.6%, 100%, and 100%, with specificities of 100%, 100%, and 99.3%, respectively. For N. gonorrhoeae, ProbeTec, Combo2, and PCR had sensitivities of 80%, 100%, and 100%, with specificities of 100%, 100%, and 98.8%, respectively. Of the total 1,000 swabs submitted, 92 were C. trachomatis infected (9.2%) and 15 were N. gonorrhoeae infected (1.5%), and 7 of these were coinfected (0.7%). There were no ProbeTec-positive/Combo2-negative samples. For C. trachomatis, ProbeTec and Combo2 had sensitivities of 81.5% and 100%, with specificities of 100% and 100%, respectively. For N. gonorrhoeae, ProbeTec and Combo2 had sensitivities of 80% and 100%, with specificities of 100% and 100%, respectively. Overall, ProbeTec had 17 C. trachomatis false-negative results (1.7%) and 3 N. gonorrhoeae false-negative results (0.3%), while Combo2 had none. Our results were consistent with the sensitivities and specificities stated by the manufacturers. NAATs perform well for detection of chlamydia and gonorrhea with self-obtained vaginal swabs shipped in a dry state to a laboratory. For 1,000 self-collected vaginal swabs tested by NAATs, the sensitivities for C. trachomatis and N. gonorrhoeae for Combo2 were 100% and 100%, while they were 81.5% and 80%, respectively, for ProbeTec. For 500 PCR samples, the C. trachomatis sensitivity was 100% and the N. gonorrhoeae sensitivity was 100%, with specificities of 99.3% and 98.8%, respectively.Each year, an estimated 3 million Chlamydia trachomatis infections occur in the United States, with over 1 million reported in 2006 surveillance reports (2). In these same reports, 358,366 cases of Neisseria gonorrhoeae infection were reported to occur in the United States (2). Since many sexually transmitted infections (STIs) are asymptomatic, especially chlamydial infections, traditional approaches to clinic-based diagnosis of STIs omit a whole segment of the population that would not ordinarily get tested. Prior to the emergence of nucleic acid amplification tests (NAATs), symptomatic persons or contacts of infected patients would be the only persons seeking care for STIs, usually at a sexually transmitted disease clinic or family planning clinic.Through the use of noninvasive urogenital samples, it is now possible to use alternative venues for screening programs outside the clinic where a clinician is not required to obtain the specimens. Utilization of self-obtained specimens for C. trachomatis and N. gonorrhoeae testing, which employ the highly sensitive and specific NAATs, has enhanced the use of noninvasive urogenital samples (9, 17). Studies have reported that self-collected vaginal specimens are acceptable and can be successfully used to diagnose STIs, especially chlamydia and gonorrhea, when they are used with NAATs (3, 14, 17, 18, 26). This can eliminate the necessity for a clinician-performed pelvic examination for women for sample collection and may represent cost savings when a woman does not require a Pap test or have symptoms (1).Expansion of alternative venues in which chlamydia testing can be performed may even be taken to Internet recruitment for home collection of vaginal swabs for mailing to a laboratory for testing (11, 13). This alternative venue may be popular among adolescents who search the Internet for health care information and information regarding STIs (20). The Internet is also used by people seeking sex partners, and these users appear to be at greater risk for STIs (22). Internet use statistics are staggering; the Pew American Life Project reports that 168 million people are on the Internet per day (http://www.pewinternet.org/reports.asp). Internet use is estimated at 83% of those aged 18 to 29 years, the prime age range in which STIs are most prevalent (http://www.pewinternet.org/reports.asp).We have successfully used an Internet-based recruitment method for home collection of self-obtained vaginal swabs for chlamydia testing (11). While such samples collected at home are not yet FDA cleared, self-obtained vaginal swabs collected in a clinic are FDA cleared for one type of NAAT (26). We therefore decided to compare the performances of the three commercially available NAATs for C. trachomatis and N. gonorrhoeae testing with vaginal samples obtained at home through an Internet screening program and mailed in a dry state (10, 17, 29) to the laboratory for testing.     

Evaluation of the Abbott LCx Ligase Chain Reaction Assay for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in Urine and Genital Swab Specimens from a Sexually Transmitted Disease Clinic Population

The Abbott LCx ligase chain reaction (LCR) assay for the simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae was evaluated by using swab and urine specimens from 562 patients. C. trachomatis results by LCR were compared to those by the Gen-Probe PACE 2 assay, whereas N. gonorrhoeae results by LCR were compared to those by culture. The Gen-Probe and LCR assays were performed according to the manufacturers’ instructions. Gram-negative diplococci growing on modified Thayer-Martin medium were confirmed as N. gonorrhoeae by the GonoGen II assay. Supplemental data analysis was performed by major outer membrane protein PCR for C. trachomatis and probes for pilin gene detection for N. gonorrhoeae. A true-positive result for each pathogen was defined as a positive result for all three or two of three assays. Overall agreement among the six assays was 94.8%. C. trachomatis prevalence was 16.2%; N. gonorrhoeae prevalence was 5.5%. The overall sensitivity and specificity, respectively, for each test (after supplemental data analysis) were as follows: for C. trachomatis, Gen-Probe, 65.9 and 100%; LCR on urine, 90.1 and 100%; LCR on swab specimens, 96.7 and 100%; and for N. gonorrhoeae, culture, 80.6 and 100%; LCR on urine, 93.5 and 99.8%; and LCR on swab specimens, 96.8 and 100%. For women, the N. gonorrhoeae culture was very insensitive compared to its performance in men (58.3 versus 94.7%, respectively). For C. trachomatis, the Gen-Probe assay’s sensitivity was lower for men than for women (62.3 versus 71.1%, respectively). The sensitivity for C. trachomatis detection by LCR on urethral and cervical swab specimens was 96.2 and 97.4% for men and women, respectively. For men, swab results were slightly better than urine results for both pathogens (sensitivity for C. trachomatis in swab and urine specimens, 96.2 and 92.5%, respectively; sensitivity for N. gonorrhoeae in swab and urine specimens, 100 and 94.7%, respectively), while for women, cervical swabs were superior in sensitivity to urine samples for detecting C. trachomatis (swab, 97.4%; urine, 81.6%) and equivalent for N. gonorrhoeae (swab, 92.3%; urine, 91.6%). The LCx LCR appears to be both sensitive and specific for the detection of C. trachomatis and N. gonorrhoeae when performed on urine or genital swab samples. Swab samples had better sensitivity than urine samples for the detection of both pathogens.     

Molecular detection and confirmation of Neisseria gonorrhoeae in urogenital and extragenital specimens using the Abbott CT/NG RealTime assay and an in-house assay targeting the porA pseudogene

Culture for detection of Neisseria gonorrhoeae (NG) is being replaced by molecular assays, but difficulties are observed with false positive and negatives results, especially for extragenital samples. This study evaluates the Abbott CT/NG Real-Time assay and a real-time porA pseudogene assay. Samples (n = 600) from a mixed prevalence Irish population include 164 male urines with corresponding urethral swabs, 58 endocervical swabs, 173 male pharyngeal swabs, 205 male rectal swabs, 36 NG clinical isolates and 26 commensal Neisseria species isolates. There was a 100% concordance between the Abbott CT/NG Real-Time and the porA assay. The positivity rate was 1.2%, 1.7%, 8.1% and 5.8% for FVU/urethral swabs, endocervical, pharyngeal and rectal swabs, respectively. These results were compared to culture and discrepancies were found with nine pharyngeal and three rectal swabs. Seven of the 12 discrepant positive samples were sequenced and were confirmed "true positives". The sensitivity and specificity of the molecular assays was 100%. The sensitivity of the culture-based testing was 100% for urogenital samples but 36% and 75% for pharyngeal and rectal swabs, respectively. The combined Abbott CT/NG and porA assays provide a valuable alternative to culture and also generate a significant increase in the diagnosis of pharyngeal and rectal NG infection.     

Evaluation of the Abbott LCx Assay for Detection of Neisseria gonorrhoeae in Endocervical Swab Specimens from Females

The Abbott LCx Neisseria gonorrhoeae assay (Abbott Laboratories, Abbott Park, Ill.) uses a ligase chain reaction (LCR) amplification in the LCx probe system for detection of a specific nucleotide sequence in the Opa-encoding gene of N. gonorrhoeae. We evaluated the LCx assay in a comparison with conventional culture employing modified Thayer-Martin media for the detection of N. gonorrhoeae from female endocervical specimens obtained from patients attending a sexually transmitted disease clinic. Discordantly LCR-positive and culture-negative specimens were further evaluated by testing with another LCR assay which used an N. gonorrhoeae-specific pilin probe. Specimens positive by both LCR assays were considered confirmed LCx-positive specimens. A specimen was considered to contain N. gonorrhoeae when it was either culture positive or culture negative and confirmed LCx positive. A total of 403 female endocervical specimens were evaluated. The prevalence of N. gonorrhoeae in this population was 8.7%. The sensitivity and specificity of the LCx assay were 94.3 and 99.4%, and those of culture were 77.1 and 100%, respectively. The Abbott LCx assay is a rapid, sensitive method for detection of N. gonorrhoeae in female endocervical specimens.     

A diagnostic evaluation of a molecular assay used for testing and treating anorectal chlamydia and gonorrhoea infections at the point-of-care in Papua New Guinea

ObjectivesPapua New Guinea has among the highest prevalences of sexually transmissible infections (STIs) globally with no services able to accurately test for anorectal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections. Here we prospectively evaluated the diagnostic performance of a molecular CT/NG assay used at the point-of-care (POC) with the aim of enhancing anorectal STI screening and same-day treatment.MethodsMen who have sex with men, transgender women and female sex workers taking part in Papua New Guinea's first large-scale biobehavioural study were enrolled and asked to provide a self-collected anorectal swab for POC GeneXpert CT/NG testing. Same-day treatment was offered if positive. A convenience sample of 396 unique and randomly selected samples were transported to Australia for comparison using the Cobas 4800 CT/NG test (Roche Molecular Diagnostics, Pleasanton, CA, USA).ResultsA total of 326 samples provided valid results by Cobas whereas 70 samples provided invalid results suggesting inhibition. The positive, negative and overall percentage agreements of GeneXpert CT/NG for the detection of C. trachomatis were 96.7% (95% CI 92.3%–98.9%), 95.5% (95% CI 91.3%–98.0%) and 96.0% (95% CI 93.3%–97.8%), and for N. gonorrhoeae were 93.0% (95% CI 86.1%–97.1%), 100.0% (95% CI 98.3%–100.0%) and 97.8% (95% CI 95.6%–99.1%), respectively.ConclusionsThe overall rate of agreement between the GeneXpert and Cobas CT/NG assays was high with 96.0% for C. trachomatis and 97.8% for N. gonorrhoeae. Results from this study data suggest that the GeneXpert CT/NG assay is suitable for testing self-collected anorectal specimens at the POC and that same-day treatment was feasible.     

Comparison of Flocked and Aptima Swabs and Two Specimen Transport Media in the Aptima Combo 2 Assay

Self-collected vaginal Aptima swabs and flocked swabs in Aptima specimen transport medium and ESwabs in ESwab medium detected all 37 Chlamydia trachomatis-infected patients from 287 women tested by the Aptima Combo assay. Prevalence rates of C. trachomatis, Neisseria gonorrhoeae, and dual infection were 12.8%, 3.1%, and 2.4%, respectively.     

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

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.     

Evaluation of the Abbott Investigational Use Only RealTime Hepatitis C Virus (HCV) Assay and Comparison to the Roche TaqMan HCV Analyte-Specific Reagent Assay

The accurate and sensitive measurement of hepatitis C virus (HCV) RNA is essential for the clinical management and treatment of infected patients and as a research tool for studying the biology of HCV infection. We evaluated the linearity, reproducibility, precision, limit of detection, and concordance of viral genotype quantitation of the Abbott investigational use only RealTime HCV (RealTime) assay using the Abbott m2000 platform and compared the results to those of the Roche TaqMan Analyte-Specific Reagent (TaqMan) and Bayer Versant HCV bDNA 3.0 assay. Comparison of 216 samples analyzed by RealTime and TaqMan assays produced the following Deming regression equation: RealTime = 0.940 (TaqMan) + 0.175 log₁₀ HCV RNA IU/ml. The average difference between the assays was 0.143 log₁₀ RNA IU/ml and was consistent across RealTime''s dynamic range of nearly 7 log₁₀ HCV RNA IU/ml. There was no significant difference between genotypes among these samples. The limit of detection using eight replicates of the World Health Organization HCV standard was determined to be 7.74 HCV RNA IU/ml by probit analysis. Replicate measurements of commercial genotype panels were significantly higher than TaqMan measurements for most samples and showed that the RealTime assay is able to detect all genotypes with no bias. Additionally, we showed that the amplicon generated by the widely used Roche COBAS Amplicor Hepatitis C Virus Test, version 2.0, can act as a template in the RealTime assay, but potential cross-contamination could be mitigated by treatment with uracil-N-glycosylase. In conclusion, the RealTime assay accurately measured HCV viral loads over a broad dynamic range, with no significant genotype bias.Methods for accurate quantitation of serum and plasma hepatitis C virus (HCV) RNA levels have become key tools both for understanding the biology of HCV infection and for the clinical management of patients under treatment. The ability to predict likelihood of response to combination interferon/ribavirin therapy by assessing rates of HCV viral load decline has provided a more individualized treatment algorithm that can identify nonresponsive patients early in treatment, sparing them significant morbidity and cost. New algorithms that examine the kinetics of HCV viral decline provide an even more refined tool for management and complement the information provided by HCV genotype determination. Finally, HCV viral kinetics data are essential for the understanding of new therapeutics such as the class of protease inhibitors. For all applications, accurate quantitation of all HCV types over a broad dynamic range is critical. The advent of real-time PCR methods provides a powerful tool for a broad dynamic range of quantitation of viruses; however, targets such as HCV require careful assay design to avoid errors due to sequence variations intrinsic to RNA viruses.Abbott Molecular, Inc. (Des Plaines, IL), recently released the m2000 system and tests for human immunodeficiency virus type 1, HCV, and chlamydia/gonorrhea (Chlamydia trachomatis/Neisseria gonorrhea) in the European Union with Conformité Européene-marked certification, and the system was recently approved for human immunodeficiency virus type 1 by the U.S. Food and Drug Administration. The m2000 system consists of an eight-channel liquid handling platform (the m2000sp) for performing automated nucleic acid extraction and PCR preparation and of a real-time PCR platform (the m2000rt) for detection and quantification. We used the m2000 system to evaluate the sensitivity, reproducibility, linearity, and concordance of viral genotype quantitation of the Abbott Molecular investigational use only (IUO) RealTime HCV (RealTime) assay and compared aspects of its performance to the Roche TaqMan Analyte-Specific Reagent (ASR) (TaqMan) (Roche Molecular Systems, Inc., Branchburg, NJ) and Bayer Versant HCV bDNA 3.0 (bDNA) assay. In addition, we examined the potential for contamination by the Roche COBAS Amplicor Hepatitis C Virus Test, version 2.0 (Amplicor) (Roche Molecular Systems, Inc., Branchburg, NJ) and TaqMan amplicons and the effect of uracil-N-glycosylase (UNG) treatment in mitigating contamination from these widely used tests.     

Epidemiology of chlamydial infection of the human genital tract: Evidence for the existence of latent infections

A group of 536 women attending a clinic for sexually transmitted diseases was investigated for cervical infection byNeisseria gonorrhoeae andChlamydia trachomatis. Conclusions have been reached concerning the existence and significance of latent and subclinical chlamydial infection of the female genital tract, and on the sexual infectivity ofChlamydia trachomatis to women. The results of the study indicate (1) demonstrable chlamydial infection in 25 % of all women attending the clinic for the first time, and in 11 % of those with unknown contact history; (2) sexual transmission ofChlamydia trachomatis; 45 % of women exposed to chlamydiae contract the infection compared with 75 % of those exposed toNeisseria gonorrhoeae; (3) the possibility of reactivation of latent chlamydial infection byNeisseria gonorrhoeae in some women.     

Effect of sexually transmitted disease (STD) coinfections on performance of three commercially available immunosorbent assays used for detection of herpes simplex virus type 2-specific antibody in men attending Baltimore, Maryland, STD clinics

Two hundred seventy-nine serum samples from men attending sexually transmitted disease (STD) clinics in Baltimore, Maryland, were tested for herpes simplex virus type 2 (HSV-2)-specific antibody by three immunosorbent glycoprotein G-2-based assays (the Kalon, Focus, and Biokit assays). The results for all samples with positive results were confirmed by Western blotting (91/279; 32.6% HSV-2 seroprevalence). All patients were also tested for Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma genitalium, human immunodeficiency virus type 1, and hepatitis C virus. The Kalon assay performed very well with samples from this population (90.8% sensitive, 99.4% specific), whereas the Focus assay had a sensitivity (82.6%) much lower than that shown previously. For 19.7% of the samples, the Biokit assay gave an indeterminate result. It was found that the odds of a sample having a Biokit assay indeterminate result compared to that of having a definitive positive or negative results were 3.88 times greater for subjects concurrently infected with N. gonorrhoeae, after the effects of other STDs were controlled for (P = 0.001; 95% confidence interval, 1.78, 8.45). Unfortunately, we were unable to control for HSV-1 infection status in the regression model, which, on the basis of χ² analysis, might also affect the clarity of the Biokit test. The recommended index cutoff value of 1.1 for the Focus and Kalon assays was found to be optimal for this population.     

Comparison of Performances of Two Commercially Available Tests, a PCR Assay and a Ligase Chain Reaction Test, in Detection of Urogenital Chlamydia trachomatis Infection

The diagnostic performance of a PCR test (Roche Cobas Amplicor CT/NG Test) and that of a ligase chain reaction (LCR) test (Abbott LCx Chlamydia trachomatis assay) were compared by using endocervical and urethral swab specimen culture as a reference test. First-void urine (FVU) and endocervical and urethral swab specimens were collected from 1,015 unselected patients attending a sexually transmitted disease clinic and a clinic for adolescents in Helsinki, Finland. Chlamydia trachomatis was cultured from samples from the endocervix or urethra. PCR was performed with fresh and frozen urine and the culture transport medium. LCR was performed with fresh and frozen urine and LCx swab transport medium. Diagnostic consistency and diagnostic accuracy were statistically tested. The test results were identical for 984 patients (97%). Discrepant results were observed for 31 patients. Overall, LCR and PCR showed excellent kappa coefficients of consistency for both swab and FVU specimens (0.93 and 0.95, respectively). Sixty-one patients (6%) were culture positive. Testing of FVU by LCR or PCR increased the overall positivity rates to 7.0 and 7.7%, respectively. While PCR of FVU detected the greatest number of C. trachomatis infections (sensitivity, 96.1%), for some PCR-positive FVU specimens the results could not be confirmed (specificity, 99.6%). PCR and LCR were more sensitive than culture (sensitivities, 92 and 93% versus 79% for culture) in the diagnosis of genital C. trachomatis infection. In conclusion, both tests can be recommended for use in the clinical laboratory and for the screening of asymptomatic C. trachomatis infections.     

High prevalence of Chlamydia trachomatis,Neisseria gonorrhoeae and particularly Trichomonas vaginalis diagnosed using US FDA‐approved Aptima molecular tests and evaluation of conventional routine diagnostic tests in Ternopil,Ukraine

Sexually transmitted infections (STIs) remain major public health problems globally. Appropriate laboratory diagnosis of STIs is rare in Ukraine. We investigated the prevalence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) using the US FDA‐approved Aptima Combo 2 and Aptima TV assays and compared the results with the conventional routine diagnostic tests (CDTs) in Ukraine. Urogenital swabs from consecutive mostly symptomatic females (n = 296) and males (n = 159) were examined. The prevalences were as follows: 10% (n = 47) of TV, 5.3% (n = 24) of CT and 1.5% (n = 7) of NG. The specificity of some CDTs was high, for example, 100% for NG culture, TV IgG ELISA, CT IgM ELISA and CT microscopy, but lower for other CDTs, that is, from 44% to 99.8%. The sensitivity of all CDTs was suboptimal, that is, 71% (n = 5) for NG microscopy, 57% (n = 4) for NG culture, 53% (n = 8) for CT IgG ELISA, 33% (n = 1) for TV IgG ELISA, 28% (n = 13) for TV microscopy, 25% (n = 1) for CT IgA ELISA, 20% (n = 3) for CT IgM ELISA and 0% (n = 0) for CT microscopy. The prevalences of particularly TV and CT were high, but substantial also for NG, in Ternopil, Ukraine. The sensitivities of all CDTs were low, and widespread implementation of validated, quality‐assured and cost‐effective molecular diagnostic STI tests in Ukraine is imperative.     

Comparative Evaluation of Chlamydiazyme, PACE 2, and AMP-CT Assays for Detection of Chlamydia trachomatis in Endocervical Specimens

We conducted a comparative evaluation of the Chlamydiazyme (Abbott Laboratories), PACE 2 (Gen-Probe), and AMP-CT (Gen-Probe) assays for the detection of Chlamydia trachomatis in endocervical samples. Specimens from 787 females were included in the study. The sensitivities of the PACE 2 and Chlamydiazyme assays in comparison to the results of the AMP-CT assay were 79.3 and 63.4%, respectively. The specificities of the Chlamydiazyme and PACE 2 assays were 100%. All of the positive specimens detected in this study were positive by the AMP-CT assay. On the basis of the final results of the comparison, the prevalence of C. trachomatis in the population was 10.4%. Retesting of specimens whose results were in the intermediate zone by the PACE 2 assay by a probe competition assay identified some additional true-positive specimens. Amplification assay testing of such specimens did not significantly increase the yield. The majority of specimens which tested positive by the AMP-CT assay only were not in the intermediate zone by the PACE 2 assay. We were unable to identify demographic or clinical factors which could predict those individuals who tested positive by amplified tests but not by nonamplified tests. The Gen-Probe PACE 2 assay proved to be superior to the Chlamydiazyme assay for the screening and diagnosis of C. trachomatis infections in female endocervical specimens.     

A retrospective study into the prevalence of herpes simplex virus 1&2 in female patients tested for Chlamydia trachomatis and/or Neisseria gonorrhoeae using vaginal swabs

The purpose of this study was to investigate the prevalence of herpes simplex virus (HSV) 1&2 in women screened for Chlamydia trachomatis and/or Neisseria gonorrhoeae (CT/GC) infections. A total of 800 vaginal swabs were tested in a dual centre investigation, to evaluate the prevalence of HSV-1&2 in this population. The average age of the population was 29.8 ± 9.2 years, ranging between 14 and 66 years with a median of 28 years. The highest prevalence of HSV-1 or HSV-2 was observed in the youngest age groups: teenagers and adults in their twenties had 5.26% and 4.31% prevalence, respectively.     

Identifying a consensus sample type to test for Chlamydia trachomatis,Neisseria gonorrhoeae,Mycoplasma genitalium,Trichomonas vaginalis and human papillomavirus

ObjectivesSexually transmitted infections (STIs) are a global cause of acute illness. Early detection plays a crucial role in interrupting transmission and preventing complications. However, the accessibility of STI testing is curbed by the lack of an overall preferred sample type. By means of a prospective study in female sex workers (FSW), we compared the sensitivity of samples from different anatomical sites in detecting Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma genitalium and human papillomavirus. Besides, we documented the prevalence of each STI in this high-risk population.MethodsWe selected 303 FSW and tested them for each STI by nucleic acid amplification testing on two vaginal and cervical swabs from different manufacturers, cervical smear and first-void urine. The sensitivity of each sample type was compared for each infectious agent in order to identify a consensus sample type.ResultsVaginal swabs were superior to all other sample types, with an overall sensitivity of 86%. The sensitivity was the lowest for first-void urine, detecting only 63% of positive cases. The prevalence was 3.3% (10/299) for Neisseria gonorrhoeae; 9.0% (27/299) for Chlamydia trachomatis; 7.4% (22/298) for Trichomonas vaginalis; 10.8% (32/296) for Mycoplasma genitalium and 55.6% (158/284) for human papillomavirus.ConclusionsWhen testing for STIs, vaginal swabs are the sample of choice and first-void urine should be avoided. Designating (self-sampled) vaginal swabs as a consensus sample type enables harmonization of STI testing and extension of testing to large numbers of unscreened females.     

An OPTIMIZE Study Retrospective Analysis for Management of Telaprevir-Treated Hepatitis C Virus (HCV)-Infected Patients by Use of the Abbott RealTime HCV RNA Assay

Protease inhibitor (PI)-based response-guided triple therapies for hepatitis C virus (HCV) infection are still widely used. Noncirrhotic treatment-naive and prior relapser patients receiving telaprevir-based treatment are eligible for shorter, 24-week total therapy if HCV RNA is undetectable at both weeks 4 and 12. In this study, the concordance in HCV RNA assessments between the Roche High Pure System/Cobas TaqMan and Abbott RealTime HCV RNA assays and the impacts of different HCV RNA cutoffs on treatment outcome were evaluated. A total of 2,629 samples from 663 HCV genotype 1 patients receiving telaprevir/pegylated interferon/ribavirin in OPTIMIZE were analyzed using the High Pure System and reanalyzed using Abbott RealTime (limits of detection, 15.1 IU/ml versus 8.3 IU/ml; limits of quantification, 25 IU/ml versus 12 IU/ml, respectively). Overall, good concordance was observed between the assays. Using undetectable HCV RNA at week 4, 34% of the patients would be eligible for shorter treatment duration with Abbott RealTime versus 72% with the High Pure System. However, using <12 IU/ml for Abbott RealTime, a similar proportion (74%) would be eligible. Of the patients receiving 24-week total therapy, 87% achieved a sustained virologic response with undetectable HCV RNA by the High Pure System or <12 IU/ml by Abbott RealTime; however, 92% of the patients with undetectable HCV RNA by Abbott RealTime achieved a sustained virologic response. Using undetectable HCV RNA as the cutoff, the more sensitive Abbott RealTime assay would identify fewer patients eligible for shorter treatment than the High Pure System. Our data confirm the <12-IU/ml cutoff, as previously established in other studies of the Abbott RealTime assay, to determine eligibility for shortened PI-based HCV treatment. (The study was registered with ClinicalTrials.gov under registration no. {"type":"clinical-trial","attrs":{"text":"NCT01241760","term_id":"NCT01241760"}}NCT01241760.)