Universal lymphogranuloma venereum (LGV) testing of rectal chlamydia in men who have sex with men and detection of asymptomatic LGV

Background Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis serovars L1-L3. This study determined the positivity for LGV testing before and after introduction of universal LGV testing of positive rectal Chlamydia trachomatis samples in men who have sex with men (MSM). Methods From March 2015 to February 2018, MSM with rectal C. trachomatis were not routinely tested for LGV at the Melbourne Sexual Health Centre unless they had HIV or symptoms of proctitis. From February 2018, universal testing for LGV of all positive rectal C. trachomatis specimens in men over the age of 25 years, regardless of symptoms was undertaken. LGV positivity was defined as the detection of LGV-associated C. trachomatis serovars. Results There were 3429 and 4020 MSM who tested positive for rectal chlamydia in the selective and universal LGV-testing periods, respectively. Of the total 3027 assessable specimens in both periods, 97 (3.2%; 95% CI 2.6% to 3.9%) specimens tested positive for LGV. LGV positivity in the selective testing period was higher than in the universal testing period (6.6% (33/502) vs 2.5% (64/2525), p<0.001). The proportion of LGV cases that were asymptomatic increased from 15.2% (5/33) in the selective testing period to 34.4% (22/64) in the universal testing period (p=0.045). Of the 70 symptomatic LGV cases symptoms included rectal discharge (71.4%, n=45) and rectal pain (60.0%, n=42). Conclusion Universal LGV testing of all positive rectal chlamydia samples in MSM compared with selective testing led to the detection of asymptomatic rectal LGV, which constituted 34% of rectal LGV cases.