Did L Strains Responsible for Lymphogranuloma Venereum Proctitis Spread Among People With Genital Chlamydia trachomatis Infection in France in 2013?

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.

2019 European guideline on the management of lymphogranuloma venereum

New or important issues in this updated version of the 2013 European guideline on the management of lymphogranuloma venereum (LGV): EPIDEMIOLOGY: Lymphogranuloma venereum continues to be endemic among European men who have sex with men (MSM) since 2003. Lymphogranuloma venereum infections in heterosexuals are extremely rare in Europe, and there is no evidence of transmission of LGV in the European heterosexual population.

AETIOLOGY AND TRANSMISSION

Chlamydia trachomatis serovars/genovars L2b and L2 are the causative strains in the majority of cases in Europe.

CLINICAL FEATURES

Among MSM, about 25% of the anorectal LGV infections are asymptomatic. Genital infections among MSM are rare; the ratio of genital vs. anorectal LGV infections is 1 in 15.

DIAGNOSIS

To diagnose LGV, a sample tested C. trachomatis positive with a commercial nucleic acid amplification test (NAAT) platform should be confirmed with an LGV discriminatory NAAT.

TREATMENT

Doxycycline 100 mg twice a day orally for 21 days is the recommended treatment for LGV. This same treatment is recommended also in asymptomatic patients and contacts of LGV patients. If another regimen is used, a test of cure (TOC) must be performed.

Extra-rectal lymphogranuloma venereum in France: a clinical and molecular study

OBJECTIVES

To describe a series of extrarectal lymphogranuloma venereum (LGV) cases diagnosed in France.

METHODS

Consecutive LGV cases confirmed at the French Reference Centre for chlamydiae with an extrarectal sample from January 2010 to December 2015 were included. The first part of the study consisted of a retrospective case note review and analysis. In a second part, the complete ompA gene sequence of our samples was determined.

RESULTS

There were 56 cases overall: 50 cases of genital LGV and six cases of pharyngeal LGV. Subjects were all men, median age 39 years, 27/53 were HIV-positive, 47/51 reported having sex with other men, 43/49 reported multiple sexual partners (a mean 25 in the last 6 months). Median time from symptom onset to diagnosis was 21 days. Subjects most commonly presented with inguinal adenopathy alone (19 of 50 genital cases) and adenopathy with genital ulcer (17 of 50). Three pharyngeal cases were symptomatic. Fever was reported in 11 cases. Inguinal abscess was reported in 22 of 42 cases presenting with lymphadenopathy. Co-infections were frequent: eight cases of syphilis, four non-LGV Chlamydia trachomatis infections, one case of gonorrhoea. Cure was always achieved with doxycycline therapy but prolonged treatment was necessary in eight cases with inguinal abscess. Genotyping according to ompA sequencing showed the co-circulation of genovars L2 (16 of 42 strains successfully typed) and L2b (24 of 42). There was no association between HIV status and disease severity or genovar distribution.

CONCLUSION

In the span of 6 years, 56 extrarectal LGV cases were confirmed through genotyping in France. Extrarectal LGV seemed to share a common epidemiological background with rectal disease in terms of affected population and genovar distribution. HIV prevalence was lower than expected.