Are <i>Ureaplasma</i> spp. a Cause of Nongonococcal Urethritis? A Systematic Review and Meta-Analysis

<div><p>Background</p><p>Nongonococcal urethritis (NGU) is the most common male reproductive tract syndrome. <i>Ureaplasmas</i> spp. including <i>U. urealyticum</i> and <i>U. parvum</i>, have been increasingly reported to be implicated in NGU. However, there are still many contradictions about their pathogenic role in NGU.</p><p>Aims</p><p>The goals of this study were to evaluate the association of <i>Ureaplasmas</i> spp. with NGU, and to compare the prevalence of <i>Ureaplasmas</i> spp. infection in China relative to the world average.</p><p>Methods</p><p>A systematic review and meta-analysis was conducted following standard guidelines for meta-analysis. The quality of included studies was assessed by Newcastle-Ottawa scale.</p><p>Results</p><p>A total of seven studies involving 1,507 NGU patients and 1,223 controls were eligible for meta-analysis. There was no significant difference in the <i>Ureaplasma</i> spp. positive rate between the NGU and control groups. However, the <i>U. urealyticum</i> positive rate was significantly higher in NGU patients compared to controls; the <i>U. parvum</i> positive rate was significantly higher in controls compared to NGU patients. Furthermore, within the NGU patient group, the positive rate of <i>U. urealyticum</i> was significantly higher than that of <i>U. parvum</i>, whereas within the control group, the opposite trend was observed. Compared to the world average, a significantly higher positive rate of <i>Ureaplasma</i> spp. was observed in both the NGU and control groups in China.</p><p>Conclusions</p><p>Our analysis supports that <i>U. urealyticum</i>, but not <i>U. parvum</i>, is an etiological agent in NGU. More detailed studies of these two species in China and the world could contribute to a better understanding of the epidemiology and pathogenesis, and facilitate the development of better strategies for treatment and prevention of NGU.</p>