The Prevalnece and Clinical Significance of Urethritis and Cervicitis in Asymptomatic People 707 tivity or specificity, false-negative results, and nonspecific interactions, Horii et al showed that the multiplex PCR as- say had an overall sensitivity of 96% and specificity of 100% compared with uniplex PCR assays. Furthermore, there was no cross-reaction with other microorganisms [29]. The multiplex PCR assay has recently made it con- venient for clinicians to test for causative organisms simul- taneously from many clinical fields [30]. Similarly, we suc- ceeded in easily generating results by use of multiplex PCR with only a single sample per person. Asymptomatic individuals play a role as reservoirs for STI. In our study, there were 50 (7.1%) infected people among 709 asymptomatic people; therefore, this pro- portion should not be neglected. An STI screening test should be considered as a part of a general checkup, espe- cially in high-risk groups, e.g., commercial sexual workers, people who have multiple sexual partners, and im- munocompromised persons [1-3,6,25]. By use of multiplex PCR, physicians can easily identify many microorganisms at once, and treating asymptomatic persons contributes to the prevention of STI in the community. CONCLUSIONS The prevalences of Chlamydia trachomatis, Neisseria gon- orrhoeae, Mycoplasma genitalium, Ureaplasma ure- alyticum, Mycoplasma hominis, and Trichomonas vagi- nalis in asymptomatic people were 5.6%, 0.4%, 0.3%, 22.1%, 11.6%, and 1.1%, respectively. We hope that these results will be used as baseline data for future studies. In our study, about 32.3% of asymptomatic people had at least one microorganism, and excluding Ureaplasma urealyticum and Mycoplasma hominis from the count, the prevalence rate of silent STI was 7.1% with multiplex PCR. 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