Sexually Transmitted Infections

Sexually-transmitted infections (STIs) constitute a major health burden in the U.S., and reported incidence among adolescents is increasing. These diseases are frequently asymptomatic and are most often caused by viruses or bacteria.

  • Diagnosis
  • Screening
  • Background
  • Lab Tests
  • References
  • Related Topics
  • Videos

Indications for Testing

  • Symptomatic individuals
    • Urgency, frequency, dysuria in the absence of a documented urinary tract infection (UTI)
    • Vaginal or penile discharge
    • Pelvic pain
    • Prostatitis symptoms
    • Genital lesions – painful vesicles, nonpainful shallow ulcer
  • Asymptomatic individuals – see Screening section for testing recommendations

Laboratory Testing

  • CDC – testing recommendations
  • Refer to the following ARUP Consult topics for sexually transmitted infection (STI) testing recommendations for
  • STI testing methods (note: for optimal specimen types and collection instructions, refer to ARUP's Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests)
    • Wet mount
      • Bacterial vaginosis – presence of clue cells is diagnostic in appropriate clinical setting
    • Nucleic acid amplification testing (NAAT)
      • Preferred for detecting Chlamydia trachomatis and Neisseria gonorrhoeae in a variety of specimens (U.S. Preventive Services Task Force [USPSTF], 2014; CDC, 2014)
      • Most sensitive test for Trichomonas vaginalis
      • Highly sensitive and specific
    • Culture
      • C. trachomatis
        • Not recommended for routine detection
        • May be considered for anatomic locations for which amplified testing has not been validated
        • May be used in medicolegal settings and to assess suspected treatment failure
        • High specificity; less sensitive than NAAT
      • N. gonorrhoeae
        • Not recommended for routine detection
        • Recommended in combination with antimicrobial susceptibility testing in cases of suspected or documented treatment failure
        • May be considered for anatomic locations for which amplified testing has not been validated
        • Sensitivity dependent on transport time viability declines rapidly during transport
      • T. vaginalis – not recommended for routine detection
    • DNA probes and direct fluorescent antibody (DFA)
      • Not recommended for routine detection
      • Lower sensitivity than NAAT

Differential Diagnosis

STI screening recommendations for sexually active nonpregnant women

STI screening recommendations for pregnant women

  • STI screening recommendations for men
  • STI screening recommendations for extragenital sites (CDC, 2014)
    • Women
      • No recommendations due to scarcity of published studies; however, available data suggests rectal and oropharyngeal infections are not uncommon in women
      • Consider screening women with known risk factors
    • Men
      • Extragenital infections are common and mostly asymptomatic – most frequent for men who have sex with men (MSM) with multiple or anonymous sexual partners
      • Screening recommended at least annually in MSM
        • Rectal specimen for men who have receptive anal intercourse
        • Pharyngeal specimen for men who have receptive oral intercourse
  • STI screening recommendations for women who have sex with women (WSW) (Wangu, 2017)
    • Due to high rates of heterosexual activity in this population, STI screening should reflect individual partner type and reported activity
  • STI screening recommendations for transgender individuals (Wangu, 2017)
    • STI screening should be based on current anatomy and sexual practices
  • Most common viral sexually transmitted infections (STIs)
  • Most common bacterial STIs
    • Treponema pallidum (syphilis)
  • Most common parasitic/protozoan STI
Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Chlamydia trachomatis and Neisseria gonorrhoeae by Transcription-Mediated Amplification (TMA) with Confirmation 2011164
Method: Qualitative Transcription-Mediated Amplification

Limitations 

Culture may be required in certain clinical contexts for diagnosing C. trachomatis and N. gonorrhoeae infections

Sexually Transmitted Disease Panel 1 by Transcription-Mediated Amplification 2006258
Method: Qualitative Transcription-Mediated Amplification

Chlamydia trachomatis and Neisseria gonorrhoeae by Transcription-Mediated Amplification (TMA) 0060241
Method: Qualitative Transcription-Mediated Amplification

Limitations 

Culture may be required in certain clinical contexts for diagnosing C. trachomatis and N. gonorrhoeae infections

Chlamydia trachomatis and Neisseria gonorrhoeae by Transcription-Mediated Amplification (TMA) with Reflex to Chlamydia trachomatis L serovars (LGV) by PCR 2013767
Method: Qualitative Transcription-Mediated Amplification/Qualitative Polymerase Chain Reaction

Chlamydia trachomatis L serovars (LGV) by PCR 2013768
Method: Qualitative Polymerase Chain Reaction

Chlamydia trachomatis Culture 0060850
Method: Cell Culture/Immunofluorescence

Limitations 

Nucleic amplification testing is recommended for detection of C. trachomatis from endocervical or urethral specimens; refer to C. trachomatis by TMA

Unusual Organism Culture 0060714
Method: Culture

Chlamydia trachomatis and Neisseria gonorrhoeae by Transcription-Mediated Amplification (TMA), ThinPrep 0060734
Method: Transcription-Mediated Amplification

Limitations 

Culture may be required in certain clinical contexts for diagnosing C. trachomatis and N. gonorrhoeae infections

Trichomonas vaginalis by Transcription-Mediated Amplification (TMA) 2005506
Method: Qualitative Transcription-Mediated Amplification

Limitations 

Performance of test on self-collected vaginal swab specimens and those from pregnant women has not been evaluated

Chlamydia trachomatis by Transcription-Mediated Amplification (TMA) 0060243
Method: Qualitative Transcription-Mediated Amplification

Limitations 

Culture may be required in certain clinical contexts for diagnosing C. trachomatis and N. gonorrhoeae infections 

Neisseria gonorrhoeae by Transcription-Mediated Amplification (TMA) 0060244
Method: Qualitative Transcription-mediated Amplification

Limitations 

Culture may be required in certain clinical contexts for diagnosing C. trachomatis and N. gonorrhoeae infections 

Guidelines

Cantor AG, Pappas M, Daeges M, Nelson HD. Screening for syphilis: updated evidence report and systematic review for the U.S. Preventive Services Task Force. JAMA. 2016;315(21):2328-2337.

Geisler WM. Management of uncomplicated Chlamydia trachomatis infections in adolescents and adults: evidence reviewed for the 2006 Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines. Clin Infect Dis. 2007; 44 Suppl 3: S77-83. PubMed

Lee KC, Ngo-Metzger Q, Wolff T, Chowdhury J, LeFevre ML, Meyers DS. Sexually Transmitted Infections: Recommendations from the U.S. Preventive Services Task Force. Am Fam Physician. 2016; 94(11): 907-915. PubMed

Newman LM, Moran JS, Workowski KA. Update on the management of gonorrhea in adults in the United States. Clin Infect Dis. 2007; 44 Suppl 3: S84-101. PubMed

Recommendations for the Laboratory-Based Detection of Chlamydia trachomatis and Neisseria gonorrhoeae - 2014. Recommendations and Reports, Vol. 63, No. 2. Centers for Disease Control and Prevention. Atlanta, GA [Published: Mar 2014; Accessed: Dec 2017]

U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. 2015 Sexually Transmitted Diseases Treatment Guidelines. Screening Recommendations. Centers for Disease Control and Prevention. Atlanta, GA [Last updated: Aug 2016; Accessed: Aug 2017]

U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines, 2015. June 5, 2015, 64(RR3);1-137. Centers for Disease Control and Prevention. Atlanta, GA [Last updated: Jun 2015; Accessed: Aug 2017]

van Schalkwyk J, Yudin MH, Infectious Disease Committee, Yudin MH, Allen V, Bouchard C, Boucher M, Boucoiran I, Caddy S, Castillo E, Kennedy L, Money DM, Murphy K, Ogilvie G, Paquet C, van Schalkwy JK, Society of Obstetricians and Gynaecologists of Canada. Vulvovaginitis: screening for and management of trichomoniasis, vulvovaginal candidiasis, and bacterial vaginosis. J Obstet Gynaecol Can. 2015; 37(3): 266-76. PubMed

Wangu Z, Burstein GR. Adolescent Sexuality: Updates to the Sexually Transmitted Infection Guidelines. Pediatr Clin North Am. 2017; 64(2): 389-411. PubMed

Zakher B, Cantor AG, Pappas M, Daeges M, Nelson HD. Screening for gonorrhea and Chlamydia: a systematic review for the U.S. Preventive Services Task Force. Ann Intern Med. 2014; 161(12): 884-93. PubMed

General References

Beharry MS, Shafii T, Burstein GR. Diagnosis and treatment of chlamydia, gonorrhea, and trichomonas in adolescents. Pediatr Ann. 2013; 42(2): 26-33. PubMed

Copeland NK, Decker CF. Other sexually transmitted diseases chancroid and donovanosis. Dis Mon. 2016; PubMed

de Vries HJ. Sexually transmitted infections in men who have sex with men. Clin Dermatol. 2014; 32(2): 181-8. PubMed

Frenkl TL, Potts J. Sexually transmitted infections. Urol Clin North Am. 2008; 35(1): 33-46; vi. PubMed

Garner AL, Schembri G, Cullen T, Lee V. Should we screen heterosexuals for extra-genital chlamydial and gonococcal infections? Int J STD AIDS. 2015; 26(7): 462-6. PubMed

Gaydos CA, Ferrero DV, Papp J. Laboratory aspects of screening men for Chlamydia trachomatis in the new millennium. Sex Transm Dis. 2008; 35(11 Suppl): S45-50. PubMed

Hobbs MM, Seña AC. Modern diagnosis of Trichomonas vaginalis infection. Sex Transm Infect. 2013; 89(6): 434-8. PubMed

Markle W, Conti T, Kad M. Sexually transmitted diseases. Prim Care. 2013; 40(3): 557-87. PubMed

Mishori R, McClaskey EL, WinklerPrins VJ. Chlamydia trachomatis infections: screening, diagnosis, and management. Am Fam Physician. 2012; 86(12): 1127-32. PubMed

Quan M. Vaginitis: diagnosis and management. Postgrad Med. 2010; 122(6): 117-27. PubMed

Verstraelen H, Verhelst R. Bacterial vaginosis: an update on diagnosis and treatment. Expert Rev Anti Infect Ther. 2009; 7(9): 1109-24. PubMed

Workowski K. In the clinic. Chlamydia and gonorrhea. Ann Intern Med. 2013; 158(3): ITC2-1. PubMed

Wright HR, Turner A, Taylor HR. Trachoma. Lancet. 2008; 371(9628): 1945-54. PubMed

Medical Reviewers

Content Reviewed: 
August 2017

Last Update: December 2017