Infection with Chlamydia trachomatis (CT) can have distinct clinical presentations, such as trachoma, or lymphogranuloma venereum (LGV). Certain populations are at greater risk for LGV acquisition and transmission, which may require a longer duration of therapy than other urogenital CT sexually transmitted infections (STIs). Commercial assays are not available in the United States to distinguish LGV from non-LGV genovars.
Methods
Lymphogranuloma venereum real-time polymerase chain reaction was performed on rectal CT-positive samples (N = 93) obtained from men (N = 80) who ordered from a mail-in self-collection STI service between April 2021 and February 2024. pmpH gene sequencing was performed on all samples to confirm LGV versus non-LGV, and multilocus sequence typing was performed on LGV-positive samples (n = 7) for additional confirmation.
Results
Lymphogranuloma venereum was detected in 7.5% (7 of 93) of samples by real-time polymerase chain reaction, with pmpH sequencing and multilocus sequence typing confirming 100% (7 of 7) of these results. Overall, pmpH sequencing data were obtained for 92% (86 of 93) of samples with the following genovar distribution based on BLAST analysis: 54% (47 of 86) J, 28% (24 of 86) F, 9% (8 of 86) E, and 8% (7 of 86) L. No individual had more than 1 LGV-positive sample. No statistically significant associations with demographic factors were identified.
Conclusions
Lymphogranuloma venereum was detected in CT-positive rectal swabs from users of an online, mail-in, self-collect STI testing platform in Maryland. These data suggest that increased LGV reflexive testing may be warranted to better understand the cotemporary epidemiology of LGV. These data also illustrate that mail-in programs for routine STI testing may be leveraged for public health surveillance purposes.