Abstract
Sirs: We read with interest the article by Lascar et al. (Int J STD AIDS 2011;
The authors, for reasons they explain, chose to exclude patients whose urethral smears showed between five and 20 polymorphs per high-power field. However, in doing so, they cannot then conclude that urethral microscopy on the patients with dysuria alone held little diagnostic benefit, as those patients may well have had between five and 20 polymorphs. Indeed, it is likely that patients with urethritis whose only symptom is dysuria have fewer polymorphs than those with urethral discharge from urethritis, which, by its nature, contains a substantial number of pus cells.
Furthermore, the phrase ‘same day microscopy’ is not defined, but we assume that it means that symptomatic patients who had fewer than five pus cells per high-power field were not required to return having held their urine overnight. As stated in the national guideline: ‘Symptomatic patients, in whom no discharge or urethritis is detected, could either be retested having held their urine overnight, or given empirical treatment.’ 1 We believe that the authors’ conclusion is not justified. Readers should not rush to judgement on the lack of utility of urethral microscopy in men whose sole symptom is dysuria.
1. Clinical Effectiveness Group. British Association for Sexual Health and HIV. 2007 UK National Guideline on the Management of Non-gonococcal Urethritis. Updated December 2008. See:
Footnotes
Author response:
Thank you for raising the important issue of low grade of inflammation on urethral microscopy and its management. As stated in recent guidelines, 1,2 a number of uncertainties remain in the management of non-gonococcal urethritis. There is a significant inter- and intra-observer error in performing and reading urethral slides. 3,4 It has been shown previously that the sensitivity of microscopy for low-grade urethritis (5–20 polymorphonuclear leukocytes [PMNL]) is only 68% and, in addition, only 75% (range 45–100%) of slides are being consistently read among microscopists. 4 It is not known how this sensitivity varies further within the group itself.
In order to dissect the magnitude of difference in microscopy outcome for different clinical presentations, we have not included patients with low-grade inflammation (5–20 PMNL) in our audit and showed that 85% of patients with dysuria alone have negative findings (0 polys group) on same day microscopy. We agree that further work is needed to establish the most effective way of managing men presenting with dysuria, from focusing on urethritis with low-grade inflammation to developing better molecular tests for other causative organisms.
We would be grateful if the grade of evidence would be added to the paragraph containing the current recommendation in the national guideline. 2 ‘Symptomatic patients, in whom no discharge or urethritis is detected, could either be retested having held their urine overnight (IV), or given empirical treatment (IV)’ as per the original reference.