1. Clinical or Epidemiological Finding Laboratory Test Suspected LGV
Figure 1
Fig 1A: LGV Case Definitions and Associated Laboratory Test (partially previously published in (2))
Case Definition
Clinical or Epidemiological
Finding
Laboratory Test
Suspected LGV
Symptoms depending on disease stage; possibly supported by diagnostic procedures (e.g., anoscopy)
a) Primary: genital ulcer, urethritis, proctitis
b) Secondary: inguinal lymphadenopathy
c) Tertiary: genital elephantiasis, lymph node scarring, fissures; or
Sexual partner of probable or confirmed case
No LGV-specific test
Standard testing for STDs with similar or overlapping symptoms, in order to rule out or diagnose (e.g., HSV, Syphilis, Chlamydia, Chancroid, Donovanosis, Gonorrhea, Trichomonas)
Probable LGV
Clinical symptoms as above; or
Swab from affected site positive for CT by commercial NAAT (rectal, urethral, penile, vaginal)
Laboratory-confirmed LGV
Clinical symptoms as above, or
Swab from affected anatomical site (previously CT NAAT+) positive for LGV by PCR
Optional for epidemiologic investigation: L1, L2, or L3 genotype determination
Fig. 1B. Laboratory Workflow for LGV outbreak investigation
CT test (NAAT)
at local laboratory
LGV-PCR test
Positive for CT
Negative for CT
Residual sample
sent to CDC
If sufficient material:
Genotyping by PCR/Sequencing (L1, L2, L3)
Negative
Positive
Patient management
Outbreak investigation
No LGV
LGV probable
LGV confirmed
CT culture ensures sufficient biological material for genotyping
Used if 1st swab unavailable
Swab from mucosal anatomical site
from suspected case
Optional: 2nd swab stored
Optional: 3rd swab for culture