O3-S4.06 Predictors of clinical treatment failure among men with idiopathic NGU
Authors: Colombara D V , Manhart L E , Wetmore C M , Lowens M. S , Kay N A , Totten P A , Golden M R 
Published: July 2011

Background

Up to half of men with nongonoccocal urethritis (NGU) have no known aetiology, yet still receive syndromic treatment. Identifying characteristics associated with clinical treatment failure may aid in determining the aetiology of these cases.

Methods

From 1 January 2007 to 31 December 2010, 553 men entered a randomised double-blind treatment trial for NGU at the Public Health Seattle & King County STD clinic in Washington. Eligible men had visible urethral discharge or ≥5 PMNs/high power field on a Gram stained slide of urethral exudates. Men were randomised to either 1 g single dose azithromycin or 100 mg doxycycline twice daily for 7 days. Chlamydia trachomatis,Neisseria gonorrhoeae, andTrichomonas vaginaliswere assessed by TMA (Gen-Probe, Inc., San Diego, CA);Mycoplasma genitaliumwas assessed by an in-house PCR assay. Ureaplasmas were detected by culture and speciated by a Ureaplasma urealyticum-biovar two specific PCR. Men negative for all pathogens were considered idiopathic and invited to return 2–5 weeks after enrolment. Clinical treatment failure was defined as visible urethral discharge or ≥5 PMNs. We evaluated baseline demographic and clinical characteristics, self-reported sexual history at enrolment, sexual practices between visits and depression as potential correlates of clinical treatment failure using log binomial regression.

Results

Of the 430 (81%) men with NGU who returned for follow-up, 202 (47%) were considered idiopathic at baseline. Enrollees were 68% white and 27% black. Age ranged from 19 to 62. Fifty-one men (25%) with idiopathic NGU experienced clinical failure. In multivariate analyses, purulent discharge at enrolment more than doubled the risk of failure (ARR=2.5, 95% CI: 1.4% to 4.4%) and black men were nearly twice as likely as non-blacks to have treatment failure (ARR=1.8, 1.1 to 2.8). Age, socioeconomic status, number of partners in last 2 months, sexual orientation, sexual behaviour (anal/vaginal sex, unprotected sex between visits), depression, and other baseline clinical characteristics were not associated with treatment failure see Abstract O3-S4.06 table 1.

Abstract O3-S4.06 Table 1

Measures of risk for clinical failure among men treated for idiopathic NGU

CharacteristicsUnivariate analysisMultivariate analysisRR (95% CI)p ValueRR (95% CI)p ValueDemographicsAge0.99 (0.97 to 1.02)0.591Black race1.66 (1.02 to 2.70)0.0421.76 (1.11 to 2.80)0.016Low socioeconomic status*1.24 (0.76 to 2.02)0.394Baseline signs and symptomsPMNs ≥101.40 (0.85 to 2.31)0.190Visible discharge1.66 (0.65 to 4.21)0.286Purulent discharge on exam1.75 (0.71 to 4.28)0.2232.51 (1.44 to 4.35)0.001Discharge amount on exam0.789SmallReferent--Moderate1.18 (0.70 to 1.99)0.536Large0.87 (0.25 to 3.08)0.834Depression (CES-D score ≥10)1.02 (0.56 to 1.87)0.936Sexual behavioursSex with a man in last 12 months0.94 (0.56 to 1.59)0.819Any anal insertive partners in last 2 months0.88 (0.51 to 1.53)0.654Any vaginal sex partners in last 2 months0.79 (0.48 to 1.29)0.343Number sex partners in last 2 months1.02 (0.96 to 1.09)0.535Any unprotected sex between visits1.06 (0.56 to 1.98)0.864*

As measured by ability to pay full price for the clinic visit vs payment on a sliding scale.

Conclusions

Treatment failure was common among men with idiopathic NGU and associated with black race and purulent discharge at enrolment. The association with purulent discharge suggests an etiologic agent that evokes a robust immune response. Insofar as race defines sexual networks, an etiologic agent present in the network may explain the observed differential risk of persistent NGU.