Genital Ulcer Multiplex PCR

August 2023
Ampath | ampath.co.za

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

📌 For further advice on STI diagnosis or test selection, contact your local Ampath pathologist.