NGU Flashcards
Which STI has been associated with balano-posthitis?
Mycoplasma genitalium (in a single study)
What %age of men have dual infection with chlamydia and m gen?
10% (up to)
List the most common pathogens of non-gonococcal urethritis (NGU)? (6)
C. trachomatis M. genitalium Ureaplasmas T. vaginalis Adenoviruses Herpes simplex virus
What is the prevalence of C. trachomatis in NGU?
50% (up to)
What is the prevalence of M. genitalium in NGU?
50% (up to)
What factors make pathogen-negative NGU more likely?
Increasing age
Absence of discharge
No clinical symptoms
What factors affect the risk of Trichomonas vaginalis causing NGU?
Background prevalence in the local community (low in UK)
More common in non-white ethnic groups
Isolation more likely in men >30 years old
Which ureaplasma is most likely pathogenic and a cause of NGU - urealyticum or parvum?
Ureaplasma urealyticum
What other symptom/sign might be present if NGU is due to an adenovirus?
Conjunctivitis
What other possible causes of NGU have occasionally been identified? Consider infective and non-infective
EBV Neisseria meningitidis Haemophilus Urethral stricture Foreign bodies
What clinical signs may prompt you to assess for NGU?
Urethral discharge
Balano-posthitis
What criteria by microscopy must be met for a diagnosis of NGU?
five or more PMNLs per high power (1000) microscopic field (averaged over five fields with the greatest concentration of PMNLs) on a smear from anterior urethra
Which part of the urethra should a sample be taken from for assessment of NGU?
Anterior urethra approximately 1 cm from urethral meatus
What microscopic field is classed as high power?
x1000
If urethral discharge is present how should this be sampled?
Sample without placing loop or swab inside meatus, if it can be adequately sampled then this is the recommended method for obtaining a smear
What device sis preferred for sampling the urethral meatus in men?
5-mm PLASTIC LOOP
It is less painful than a Dacron swab which is less painful than a Rayon swab
If urethral smear is negative for NGU or microscopy is not available, what other assessment may be made to further consider NGU?
Performing a LEUCOCYTE ESTERASE DIPSTICK on the remains of the FVU specimen could be considered and if 1+ OR MORE, a diagnosis of NGU could be made.
However it t does not have adequate sensitivity to be considered a reliable rapid diagnostic test for acute NGU instead of microscopy
If microscopy and a dipstick analysis are negative for NGU but the patient still has symptoms, what should the next approach of investigation be?
Attend for early morning smear and hold urine overnight.
When performing a urethral smear what is the optimum time to ensure a definite diagnosis in a symptomatic man?
2-4 hours (conventional approach). However no definitive evidence
What are the benefits of treating NGU with doxycycline 100mg BD for 7 days?
> 95% effective in men who are chlamydia positive
M. genitalium-positive there is no evidence that it induces antimicrobial resistance
It is as effective as azithromycin 1 g in men who are U. urealyticum-positive.
Whys is azithromycin not used as first line treatment for NGU?
<90% effective in men who are M. gen positive
If M. gen positive - risk of developing 23sRNA gene mutation and therefore antimicrobial resistance
What is the duration of the ‘look back’ period for partner notification for NGU?
4 weeks
What is the definition of persistent NGU?
symptoms do not resolve following treatment
What is the definition of recurrent NGU?
recurrence of symptoms within 30-90 days following treatment of acute NGU?
How common is persistent NGU?
15-25%
How common is recurrent NGU?
10-20%
What percentage of persistent NGU is an infectious cause identified?
<50%
In addition to re-examination and assessment and testing for mycoplasma genitalium, what else should be considered testing for in persistent/recurrent NGU?
Trichomonis vaginalis NAAT (if available)
