Overview
The majority of genital ulcers are caused by sexually transmitted infections (STIs). Accurate diagnosis is crucial because:
- Genital ulcers increase the risk of HIV acquisition
- Patients may be co-infected with multiple pathogens
Common causative organisms include:
- Herpes simplex virus type 1 and 2 (HSV1, HSV2)
- Treponema pallidum (syphilis)
- Haemophilus ducreyi (chancroid)
- Chlamydia trachomatis L1–L3 (lymphogranuloma venereum)
- Klebsiella granulomatosis (granuloma inguinale) (not detected by this test)
Other important causes in certain populations:
- Varicella zoster virus – may involve genital area
- Cytomegalovirus (CMV) – particularly in immunocompromised patients
- Monkeypox virus – included due to the recent global outbreak
Monkeypox and Genital Ulcers
- Monkeypox virus is a zoonotic infection spread by close contact with lesions, respiratory secretions, or contaminated objects
- Since 2022, outbreaks have occurred globally, including South Africa
- Most cases have involved men who have sex with men (MSM)
- Monkeypox should be included in the differential diagnosis for patients presenting with genital ulcers
- A dedicated PCR test is available at Ampath using the mnemonic:
MONPOXPCR
Genital Ulcer Multiplex PCR: Pathogens Detected
Viruses
- HSV-1:
- Causes multiple painful vesicular lesions that ulcerate
- Most common genital ulcer cause
- HSV-2:
- Similar presentation to HSV-1
- Often associated with recurrent episodes
- Varicella zoster virus (VZV):
- May involve genital area
- Clinically resembles HSV
- Cytomegalovirus (CMV):
- Seen mainly in immunocompromised patients
- May mimic HSV clinically
Bacteria
- Treponema pallidum (syphilis):
- Single painless ulcer (chancre) with clean base and firm border
- May present atypically (multiple ulcers) in HIV-positive patients
- Perform syphilis serology in conjunction
- Haemophilus ducreyi (chancroid):
- Painful ulcer(s) with necrotic base
- Tender inguinal lymphadenopathy common
- Chlamydia trachomatis L1–L3 (lymphogranuloma venereum / LGV):
- Small painless ulcer or papule
- Tender inguinal lymphadenopathy
- In MSM, may involve rectum (tenesmus, pain, discharge, constipation)
Note: Klebsiella granulomatosis is not detected by this assay. It requires tissue smear and microscopy for Donovan bodies.
Test Details
- Mnemonic:
GENULPCR - Turnaround time: 48–72 hours (from lab receipt)
- Validated specimen types:
- Genital ulcer swabs
- Liquid-based cytology samples
- Bubo aspirates
- Rectal swabs
Ampath Results Summary (2-Year Review)
- 62% of samples tested positive for at least one pathogen
- HSV-2 was the most common (31%)
- CMV was second most common (21%)
- 15% of positives were co-infections, most commonly HSV-2 + CMV
Why Choose the Multiplex PCR?
- Covers a wide range of relevant pathogens
- Cost-effective compared to standalone HSV PCR
- Allows efficient diagnosis, especially in high-risk or immunocompromised patients