Detection ofChlamydia trachomatisandNeisseria gonorrhoeaein an STI population: performances of the Presto CT-NG assay, the Lightmix Kit 480 HT CT/NG and the COBAS Amplicor with urine specimens and urethral/cervicovaginal samples

Abstract

ObjectivesThis study assessed the performances of the Presto CT-NG assay, the Lightmix Kit 480 HT CT/NG and the COBAS Amplicor for Chlamydia trachomatis and Neisseria gonorrhoeae detection.DesignA cross-sectional study design.SettingIzore, Centre for Diagnosing Infectious Diseases in Friesland, the Netherlands, tested samples sent from regional sexually transmitted infection (STI) outpatient clinics and regional hospitals from the province Friesland, the Netherlands.ParticipantsSamples were collected from 292 men and 835 women. These samples included 560 urine samples and 567 urethral/cervicovaginal samples.Primary and secondary outcome measuresThe primary outcome measure is C trachomatis infection. No secondary outcome measures are available.ResultsThe sensitivity, specificity, positive predicative value (PPV) and negative predictive value (NPV) for C trachomatis detection in urine samples using the Presto CT-NG assay were 100%, 99.8%, 98.1% and 100%, respectively; for the Lightmix Kit 480 HT CT/NG: 94.2%, 99.8%, 96.1% and 99.4%, respectively; for the COBAS Amplicor: 92.3%, 99.6%, 96% and 99.2%, respectively. The sensitivity, specificity, PPV and NPV for C trachomatis detection in urethral/cervicovaginal swabs using the Presto CT-NG assay and the COBAS Amplicor were 100%, 99.8%, 97.7% and 100%, respectively; for the Lightmix Kit 480 HT CT/NG: 100%, 99.6%, 97.7% and 100%, respectively. Calculations for N gonorrhoeae could not be made due to a low prevalence.ConclusionsAll three assays had a high sensitivity, specificity, PPV and NPV for C trachomatis, with best performance for the Presto CT-NG assay.

Implementation and evaluation of the Presto combined qualitative real-time assay for Chlamydia trachomatis and Neisseria gonorrhoeae in Rwanda

“…Notwithstanding this study’s small sample size, the Presto assay’s sensitivity and specificity for C. trachomatis detection was in line with two previous studies. 6,7 We cannot explain the lower specificity found for N. gonorrhoeae detection; we did not obtain cross reactions with the non-gonorrhoeae Neisseria species, and we therefore advise that a possible lower specificity should be confirmed in future studies. A total of eight equivocal results (4.2%) were found during this small evaluation.…”

“…The Presto CT/NG PCR assay is characterised by its flexibility in use of sample types (with or without transport medium), DNA can be isolated using any system and it can be implemented on different real-time PCR amplification platforms. 6,7 In addition, it provides faster results and considerably reduces the risk of contamination by amplicons compared to end-point PCR.…”

Sexually Transmitted Infections and Behavioral Determinants of Sexual and Reproductive Health in the Allahabad District (India) Based on Data from the ChlamIndia Study

“…All were positive, suggesting correct sample collection. Furthermore, the PCR/NAAT assay used in this study had previously been employed in similar studies that were conducted in, and on samples from, both high and low-resource settings (The Netherlands, South Africa, and Tanzania) [22,23]. These studies were successful in identifying CT and NG DNA while making use of the same techniques.…”

“…The fact that all samples were negative for CT and NG DNA was quite unexpected and led to the consideration of the following steps: (1) The PCR was performed by a local technician in India, trained by an experienced Dutch researcher who also controlled all of the results. No technical issue suggestive of potentially false negative results was encountered at this stage; (2) The equipment used in India was identical to, and validated and used in the same way as the equipment used in The Netherlands, suggesting no equipment-based issues [22]; (3) Serial dilutions of positive controls gave the same range in both India and The Netherlands, suggestive of no sensitivity issues at the Indian test site; (4) All PRESTO assay IACs were positive, indicating good DNA isolation and efficient PCR performance without inhibition; and (5) A series of samples were tested for a human HLA target to ensure the samples contained human DNA. All were positive, suggesting correct sample collection.…”

Utilidad del Cobas® Taqman® Ct Test, v2.0 para la detección de cepas de Chlamydia Trachomatis circulantes en México

“…Sin embargo, de éstas últimas, solo 8 de 10 analizadas se confirmaron como positivas en el sistema BD ProbeTec ET (BD ProbeTec ET CT/GC Amplified DNA) mientras que por el sistema Abbott las 10 analizadas fueron positivas. La explicación dada por Hadad y Col., de las dos muestras que no se confirmaron por el sistema ProbeTec fue debido a que este sistema muestra menor (26) sensibilidad que el sistema COBAS® , o que el medio de transporte no fue el adecuado para el aislamiento del (26) ADN, o el tipo de almacenamiento, o el transporte de las muestras, etc., . Sin embargo, otra posibilidad no descrita por estos autores es que fueran cepas con mutaciones en los sitios blancos de amplificación.…”