by Jason Wong, Physician Epidemiologist, Clinical Prevention Services, BCCDC; and, Linda Hoang, Medical Microbiologist, Laboratory Services, BCCDC; and, Troy Grennan, Medical Head, STI Clinic, Clinical Prevention Services, BCCDC; and, Carolyn Montgomery, Physician Sessional, Clinical Prevention Services, BCCDC; and, Sylvia Makaroff, Physician Sessional, Clinical Prevention Services; BCCDC
Lymphogranuloma venereum (LGV) is a sexually transmitted infection caused by Chlamydia trachomatis serovars L1, L2 and L3.
Though LGV was first reported in BC in 2004, there has been a significant increase in the number of reported LGV cases since late 2010, particularly among HIV-positive gay, bisexual, and other men who have sex with men (MSM).
Depending on the site of infection, the clinical presentation of LGV may include:
- genital ulcers
- large, painful inguinal lymphadenopathy
- hemorrhagic proctitis (i.e., the anorectal syndrome)
Unlike C. trachomatis, untreated LGV may lead to serious sequelae such as lymphatic obstructions, chronic ulcerations, or colorectal strictures/fistulae.
Laboratory testing for LGV
Diagnosis of LGV first requires laboratory confirmation of C. trachomatis either by nucleic acid amplification testing (NAAT) or culture. Community laboratories (e.g., LifeLabs), the BC Public Health Microbiology and Reference Laboratory (BCPHMRL), and hospital laboratories can perform NAAT detection for C. trachomatis.
In BC, all rectal specimens that have tested positive for C. trachomatis are forwarded to BCPHMRL then to the National Microbiology Laboratory (NML) for LGV serovar testing.
The BCPHMRL informs both the submitting laboratory and the BC Centre for Disease Control (BCCDC) of a positive LGV result the same day results are received from NML.
Specimen collection for LGV testing
Clinicians suspecting LGV infection should carry out all of the following to ensure laboratory testing for LGV:
- Use the blue-shaft unisex swab from the GEN-PROBE® APTIMA® chlamydia and gonorrhea collection kit
- Mark the box for “rectal” site under the “Chlamydia (CT) & Gonorrhea (GC)” section of the lab requisition form
- Print “query LGV” on the lab requisition form
Public health follow-up for reported LGV cases
All genital chlamydia diagnoses, including LGV, are reportable under the BC Public Health Act.
Public health follow-up of LGV cases (confirmed and probable) is managed centrally at BCCDC. A BCCDC nurse will contact the diagnosing clinician to ensure that the case receives adequate treatment, to coordinate the partner notification process, and to assist in the completion of an enhanced case report form for LGV surveillance in BC.
- Confirmed – DNA sequencing for the presence of C. trachomatis serovars L1, L2 or L3.
- Probable – either (1) a positive NAAT or culture for C. trachomatis and either proctitis, inguinal or femoral lymphadenopathy, suspicious lesion, or having a sexual partner who is a confirmed or probable LGV case or (2) clinical symptoms consistent with LGV and having a sexual partner who is a confirmed or probable LGV case.
Trends in reported LGV cases in BC
In BC, a sharp increase was observed in both reported LGV cases (confirmed and probable) in 2011 and rectal chlamydia cases in 2012 (Figure 1).
From 2010 to 2014, 83 LGV cases (77 confirmed, 6 probable) were reported in BC. All cases were MSM between the ages of 20 and 68 years; 93% (77/83 cases) resided in Greater Vancouver; 74% (61/82 cases) identified as Caucasian; and 93% (67/72 cases) presented with symptoms of proctitis. Five cases were documented as asymptomatic. Of those with known HIV status, 68% (54/79 cases) were co-infected with HIV. All confirmed cases belonged to the L2b serotype.