Analysis of 721 Chlamydia trachomatis-positive urogenital specimens from men and women using lymphogranuloma venereum L2-specific real-time PCR assay

Chlamydia trachomatis Biovar L2 Infection in Women in South Africa

We detected Chlamydia trachomatis biovar L2 in vaginal swab specimens of 7 women with vaginal discharge in South Africa. Whole-genome sequencing directly from clinical specimens identified a closely related cluster of strains. The clinical role of this infection in the context of syndromic management should be clarified.

No evidence for LGV transmission among heterosexuals in Amsterdam, the Netherlands

Background

In recent years a few cases of lymphogranuloma venereum (LGV) in heterosexuals in Europe have been reported. It is not known whether LGV transmission among heterosexuals occurs on a wider scale.

Methods

Heterosexual male and female STI clinic clients (n = 587) in Amsterdam, the Netherlands, with a positive nucleic acid amplification test (NAAT) result for Chlamydia trachomatis (CT) were screened for IgA anti-MOMP in serum. If the value was above the cut-off index (2.0) the patient’s CT positive urogenital, ocular or rectal sample(s) were selected and tested for LGV by an in-house LGV-specific NAAT.

Results

Sera of 126 patients were above 2.0 COI. Some patients had >1 CT positive sample. Samples could not be retrieved from 15 of the 126 persons, and 7 samples that were found positive for CT in the diagnostic amplification process could not be confirmed and hence not typed. We did not find a single case of LGV infection in 123 urogenital, ocular or rectal samples from 104 patients.

Conclusion

We found no indications for significant spread of LGV infection in heterosexuals in Amsterdam. Surveillance in females with cervical or anal CT infection is indicated to monitor LGV occurrence in heterosexuals.

Anal infections with concomitant Chlamydia trachomatis genotypes among men who have sex with men in Amsterdam, the Netherlands

Background

Lymphogranuloma venereum (LGV) proctitis is caused by Chlamydia trachomatis (Ct) genotype L and is endemic among men who have sex with men (MSM) in western society. Genotype L infections need to be distinguished from non-LGV (genotypes A-K) Ct infections since they require prolonged antibiotic treatment. For this purpose, an in-house developed pmpH based LGV polymerase chain reaction (PCR) test is used at the Amsterdam STI outpatient clinic. We investigated retrospectively the anal Ct genotype distribution, and the frequency of concomitant genotype infections in MSM infected with LGV and non-LGV Ct infections. To detect concomitant Ct genotype infections, the pmpH LGV PCR and genoTyping Reverse Hybridization Assay (Ct-DT RHA) were used.

Methods

A total of 201 Ct positive rectal swabs from MSM were selected, which were previously diagnosed as either LGV (n = 99) or non-LGV Ct infection (n = 102) according to the algorithm of Ct detection by the commercially available Aptima Combo 2 assay followed by an in-house pmpH LGV PCR. The samples were retested with the commercially available Ct-DT RHA, which differentiates between 14 major genotypes and is able to detect concomitant Ct genotypes.

Results

Excellent genotyping agreement was observed between the Ct-DT RHA and the pmpH LGV PCR (Kappa = 0.900, 95%CI = 0.845-0.955, McNemar's p = 1.000). A concomitant non-LGV genotype was detected in 6/99 (6.1%) LGV samples. No additional LGV infections were observed with the Ct-DT RHA among the non-LGV Ct group. In the non-LGV group genotype G/Ga (34.3%) was seen most frequent, followed by genotype D/Da (22.5%) and genotype J (13.7%). All LGV infections were caused by genotype L2.

Conclusions

Concomitant non-LGV genotypes do not lead to missed LGV proctitis diagnosis. The pmpH LGV PCR displayed excellent agreement with the commercially available Ct-DT genotyping RHA test. The genotypes G/Ga, D/Da and J were the most frequent non-LGV Ct strains in MSM.

Lymphogranuloma venereum proctocolitis: a silent endemic disease in men who have sex with men in industrialised countries

Lymphogranuloma venereum (LGV) is a sexually transmitted disease (STD) caused by serovars L1-L3 of Chlamydia trachomatis. Rare in the western world prior to 2003, different outbreaks or clusters of LGV have been reported in Europe, North America and Australia among men who have sex with men (MSM) over the past few years. The majority were HIV infected MSM with high-risk sexual behaviour and a high rate of concomitant STD, including hepatitis C. Most of them presented with a proctitis syndrome and only a few with the classical bubonic form. A previously non-described serovar, L2b, has been identified as the main causative agent of the epidemic. A delay in diagnosis has been the rule because of the misleading symptomatology of LGV proctitis, the unfamiliarity of the disease to physicians, and the lack of a routine diagnostic test for LGV serovars. It is crucial to increase the awareness of the disease among physicians for prompt diagnosis and treatment, to avoid complications, and to stop ongoing transmission. It has additional public health implications since LGV may facilitate the transmission and acquisition of HIV and other STD.

Rapid detection of Chlamydia trachomatis and typing of the Lymphogranuloma venereum associated L-Serovars by TaqMan PCR

Background

Infection due to Chlamydia trachomatis is the most common sexually transmitted bacterial disease of global health significance, and especially the L-serovars causing lymphogranuloma venereum are increasingly being found in Europe in men who have sex with men.

Results

The design and evaluation of a rapid, multiplex, real-time PCR targeting the major outer membrane protein (omp-1) -gene and a L-serovar-specific region of the polymorphic protein H (pmp-H) -gene for the detection of Chlamydia trachomatis is reported here. The PCR takes place as a single reaction with an internal control. For L1-, L2- and L3-serovar differentiation a second set of real-time PCRs was evaluated based on the amplification of serovar-specific omp-1-regions. The detection limit of each real-time PCR, multiplexed or not, was 50 genome copies per reaction with an efficiency ranging from 90,5–95,2%.

In a retrospective analysis of 50 ocular, rectal and urogenital specimens formerly tested to be positive for C. trachomatis we identified six L2-serovars in rectal specimens of HIV-positive men, one in a double-infection with L3, and one L2 in a urethral specimen of an HIV-negative male.

Conclusion

This unique real-time PCR is specific and convenient for the rapid routine-diagnostic detection of lymphogranuloma venereum-associated L-serovars and enables the subsequent differentiation of L1, L2 and L3 for epidemiologic studies.