Definitions for the level of evidence (I-IV) and grade of recommendation (A-C) are provided at the end of the "Major Recommendations" field.
Widespread screening is currently not recommended; the need to test for lymphogranuloma venereum (LGV) will arise in the following patients:
- Patients presenting with an acute proctitis who have been at high risk.
- Patients presenting with inguinal buboes (inflammatory lymph node swellings in the inguinal-femoral lymph gland group), and a suggestive travel history.
- Patients with manifestations of late stage disease
- Sexual contacts of confirmed cases of LGV infection
Recommended Tests
The laboratory diagnosis is dependent on the detection of Chlamydia trachomatis (C. trachomatis) specific DNA followed by genotyping to identify serovars L1, L2 or L3.
- The method of choice for the laboratory diagnosis of LGV is the detection of C. trachomatis specific DNA belonging to an LGV serovar, L1, L2 or L3.
- The first step is the detection of C. trachomatis using a nucleic acid amplification test (NAAT). Routinely available NAATs for C. trachomatis will detect all serovars including LGV serovars and are licensed for genital specimens. However, rectal specimens need to be tested in most patients recently identified. There are no licensed NAATs for the detection of C. trachomatis in rectal specimens, but data is available supporting the validity of these tests for use with rectal specimens (Evidence Level III, Grade of Recommendation B).
- Confirmation of the presence of LGV specific deoxyribonucleic acid (DNA) can then be obtained by direct detection of LGV specific DNA using real-time polymerase chain reaction (PCR). Alternatively genotyping can be performed by amplifying the omp1 gene followed by restriction endonuclease digestion to identify specific serovars. An additional restriction fragment length polymorphism (RFLP) method is based on the digest of the CrP gene which differentiates between L1-3. (Evidence Level III, Grade of Recommendation B).
- The Health Protection Agency has published an algorithm for the detection of LGV, which recommends that any NAAT positive for C. trachomatis from men who have sex with men presenting with proctitis should be sent to the Sexually Transmitted Bacteria Reference Laboratory (STBRL) for confirmation. At STBRL, the C. trachomatis status of the specimen will be confirmed using an 'in house' real-time PCR with independent primers specific to all unknown C. trachomatis strains. Specimens positive for C. trachomatis will be screened using reverse transcriptase (RT)-PCR to detect LGV serovars directly including L1, L2 and L3. Any LGV positive samples will be genotyped to determine the LGV serovar. (Evidence Level III, Grade of Recommendation B).
- Typing for epidemiological purposes using DNA sequencing of the omp1 gene should only be performed at a reference laboratory.
- Culture is the most specific test but very few laboratories have culture facilities and sensitivity can be prejudiced by the toxic nature of bubo aspirates (Evidence Level IV, Grade of Recommendation C).
- Serology may be useful if direct detection has been unsuccessful. A high titre in a patient with symptoms is highly suggestive of LGV. However, a low titre cannot exclude LGV and a high titre in the absence of symptoms cannot confirm LGV. The two methods most used have been complement fixation (CF) and microimmunofluorescence-immunoglobulin G (MIF-IgG); single point titres of greater than or equal to 1/64 (Evidence Level IV, Grade of Recommendation C) and 1/256 respectively are considered positive. The whole inclusion fluorescence test has also been used. Where MIF is used, it is important that a L serovar is included as an antigen.
- There are now many commercial immunoassays on the market for C. trachomatis serology but their use for LGV diagnosis has not been reported. Many of these kits use undisclosed peptide antigens that may not include LGV serovar sequences and thus are not recommended.
Recommended Sites for Testing
- Ulcer material (if ulcer is present)
- Lymph node aspirate (may require injection and re-aspiration of saline)
- Lymph node biopsy (if investigation by other means is unsuccessful)
- Rectal swabs (if proctitis is present)
- Urine
- Urethral swab
- Rectal biopsy tissue
- Clotted blood (for serology)
Factors Which Alter Tests Recommended or Sites Tested
Sites for testing will be determined by the clinical presentation. Clinicians should consult with their microbiology laboratory colleagues to alert them regarding unusual specimens and to inform them that specialist tests will be required.
Sexual History
- Travel to, and sexual exposure in, an LGV endemic country by the index patient or his/her partner (no alteration to standard recommendation).
Risk Groups
- Men Who Have Sex with Men (MSM) with high risk behaviour, in particular attendance at sex parties, anonymous sex, fisting and use of enemas (no alteration to standard recommendation).
- Patients who are known contacts of the infection (no alteration to standard recommendation)
Recommendation for Frequency of Repeat Testing in an Asymptomatic Patient
DNA Amplification Tests: Repeat testing four weeks after exposure only in individuals with known or strongly suspected exposure to LGV if the initial test has been done within three weeks of exposure and epidemiological treatment has been declined.
Serology: Repeat testing is only required if symptoms suggestive of LGV develop following the initial test.
Recommendation for Test of Cure and Follow Up
Test of cure is necessary and should be provided 3 to 5 weeks after treatment. For those very few patients who may have extensive lesions or fistulas as a result of late treatment, surgical intervention may be required.
Definitions:
Levels of Evidence
Ia: Evidence obtained from meta-analysis of randomised controlled trials
Ib: Evidence obtained from at least one randomised controlled trial
IIa: Evidence obtained from at least one well designed controlled study without randomisation
IIb: Evidence obtained from at least one other type of well designed quasi-experimental study
III: Evidence obtained from well designed non-experimental descriptive studies
IV: Evidence obtained from expert committee reports or opinions and/or clinical experience of respected authorities
Grading of Recommendations
- Evidence at level Ia or Ib
- Evidence at level IIa, IIb, or III
- Evidence at level IV
