Evaluation of 2 Commercial Assays for the Detection of Lymphogranuloma Venereum in Rectal Samples

[Translated article] AEDV Expert Consensus Document on the Organization of a Multidisciplinary Unit for Patients With or at Risk of Venereal Infections

Over the past few years, venereal or sexually transmitted infections (STIs) have been on the rise worldwide requiring additional specialized monographic consultations to specifically treat STIs. Therefore, the Spanish Academy of Dermatology and Venereology (AEDV) Research Working Group on STIs and HIV has drafted this document with the necessary requirements in terms of infrastructure, personnel, technology, specific materials for sample collection, and needs for current therapeutic options. Strict emphasis is placed on the protection of patient privacy. A health care circuit model is outlined too. Additionally, a section has been included on contact tracking and reporting, key elements for the effective prevention and control of STIs. These clinical practice guidelines seek to establish a clinical action framework adapted to the current challenges posed by STIs and HIV in the dermatology, venereology, and multidisciplinary settings.

AEDV Expert Consensus Document on the Organization of a Multidisciplinary Unit for Patients With or at Risk of Venereal Infections

Over the past few years, venereal or sexually transmitted infections (STIs) have been on the rise worldwide requiring additional specialized monographic consultations to specifically treat STIs. Therefore, the Spanish Academy of Dermatology and Venereology (AEDV) Research Working Group on STIs and HIV has drafted this document with the necessary requirements in terms of infrastructure, personnel, technology, specific materials for sample collection, and needs for current therapeutic options. Strict emphasis is placed on the protection of patient privacy. A health care circuit model is outlined too. Additionally, a section has been included on contact tracking and reporting, key elements for the effective prevention and control of STIs. These clinical practice guidelines seek to establish a clinical action framework adapted to the current challenges posed by STIs and HIV in the dermatology, venereology, and multidisciplinary settings.

Use of real-time PCR as an alternative to conventional genotyping methods for the laboratory detection of lymphogranuloma venereum (LGV)

Lymphogranuloma venereum (LGV) can be differentiated from non-LGV chlamydial infection using Sanger sequencing or molecular assays, including those that are commercially-available internationally. Here, we describe the performance of a rapid real-time PCR (RT-PCR)-based strategy in differentiating Chlamydia trachomatis infections associated with LGV or non-LGV serovars. One hundred three rectal swabs, previously genotyped using Sanger sequencing of the ompA gene as a reference method, were tested in the RT-PCR assays. All non-LGV specimens were correctly identified, but the RT-PCR failed to detect 1 LGV specimen, resulting in a sensitivity of 87.5% for the non-LGV/LGV RT-PCR assay. Additional performance characteristics (e.g., specificity, accuracy, and reproducibility) were all between 93% and 100% with a limit of detection ≤100 copies/reaction. Thus, this rapid RT-PCR method for LGV detection in clinical specimens is comparable to the reference method.

Evaluation of four commercial real-time PCR assays for the detection of lymphogranuloma venereum in Chlamydia trachomatis-positive anorectal samples

OBJECTIVES

Lymphogranuloma venereum (LGV) is a sexually transmitted infection (STI) caused by Chlamydia trachomatis (CT) genovars L. The identification of LGV is of therapeutic interest because treatment requires 3 weeks of doxycycline compared with 1 week for infection with a non-L strain. The aim of this study was to evaluate the performance of four commercial real-time PCR kits in comparison with the reference methods used for LGV diagnosis by the French National Reference Centre (NRC) for bacterial STIs.

METHODS

A total of 215 French CT-positive anorectal specimens collected consecutively in 2017 were used (66 LGV and 149 non-LGV). Among these, 92 were collected from symptomatic men who have sex with men (MSM) and 123 from asymptomatic MSM using pre-exposure prophylaxis. Four commercial assays were evaluated; a single-plex assay RealCycler CHSL kit (Progenie Molecular), tested on all the specimens, and three multiplex kits, the RealCycler Universal ULCGEN (Progenie Molecular), the Allplex Genital Ulcer Assay (Seegene) and the VIASURE Haemophilus ducreyi + CT LGV Real Time PCR Detection kit (CerTest Biotec), tested on the 92 samples from symptomatic MSM. Clinical performance was determined in comparison to the in-house real time PCR targeting the pmpH and the ompA gene sequencing.

RESULTS

Overall agreement ranged between 91.3% and 100% (95% CI 83.7-100%) with very good Kappa index values (>0.8). The clinical sensitivities and specificities varied between 91% and 100% (95% CI 80.8-100%), and 97% and 100% (95% CI 87.1-100%), respectively, with some kits performing better than others.

DISCUSSION

The four assays showed very good performance for the detection of LGV on anorectal specimens.