Sexually Transmitted Infections

Indications for Testing

Urgency, frequency, dysuria in the absence of a documented UTI
Vaginal or penile discharge
Pelvic pain
Proctitis symptoms

Laboratory Testing

Refer to the following ARUP Consult topics for STI testing recommendations for the following
CDC – testing recommendations
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 C. trachomatis and N. gonorrhoeae in a variety of specimens (USPTFS, 2014; CDC, 2014)
  - Most sensitive test for T. 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
      - N. gonorrhoeae is fastidious; viability declines rapidly during transport
  - T. vaginalis
    - Not recommended for routine detection
- DNA probes and DFA
  - Not recommended for routine detection
  - Lower sensitivity than NAAT

Differential Diagnosis

Urinary tract infection
Vaginitis/cervicitis
Vulvovaginal candidiasis
Malignancy – ovarian cancer, cervical cancer
Nephrolithiasis
Ectopic pregnancy
Diverticulitis
Inflammatory bowel disease
Appendicitis
Pregnancy
Ovarian cyst

For optimal specimen types and collection instructions for STI screening tests, refer to ARUP's Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests
STI screening recommendations for women

STI screening recommendations for sexually active nonpregnant women (STI/Syphilis) node 1218

STI screening recommendations for sexually active nonpregnant women

STI Screening Recommendations for Sexually Active Nonpregnant Women
STI	USPSTF	CDC	AAFP	ACOG
Chlamydia	Annual screening – women <25 years and others at increased risk* Do not screen women >25 years and not at high risk	Annual screening – women <25 years and others at increased risk* Do not screen women >25 years and not at high risk	Screen women ≤25 years and others at increased risk*	Screen women ≤25 years and others at increased risk****
Gonorrhea	Screen women <25 years and others at increased risk* No recommendation for or against screening women not at risk and >25 years	Screen women <25 years and others at increased risk* No recommendation for or against screening women not at risk and >25 years	Screen women <25 years and others at increased risk*	Screen adolescents and others at increased risk****
Syphilis	Screen women at increased risk**	Screen women exposed to syphilis	Screen women at increased risk*	Screen women at increased risk****
HIV	Screen women at increased risk*	Screen all patients 13-64 years regardless of risk factors	Screen women at increased risk*	Screen women at increased risk****
Hepatitis B	Do not screen general population	Provide prevaccination screening for women at increased risk***	Do not screen general population	No specific recommendation
Hepatitis C	Do not screen general population; insufficient evidence to recommend for or against screening women at increased risk	Screen women at increased risk*** Do not screen general population	Do not screen general population; insufficient evidence to recommend for or against screening women at increased risk*	Screen women at increased risk****
HSV	Do not screen asymptomatic patients	Screening not recommended	Do not screen general population	Screen if sex partner has HSV
HPV	Insufficient evidence to use as primary screening test for cervical cancer	Screening not recommended until 25 yrs	Insufficient evidence to use as primary screening test for cervical cancer	Testing with a Pap smear is an option for women >30 years
Bacterial vaginosis	Screening not recommended	Screening not recommended	No specific recommendations	No specific recommendations
STI = sexually transmitted infection; USPSTF = U.S. Preventive Services Task Force; CDC = Centers for Disease Control and Prevention; AAFP = American Academy of Family Physicians; ACOG = American Congress of Obstetricians and Gynecologists; HIV = human immunodeficiency virus; HSV = herpes simplex virus; HPV = human papillomavirus; Pap = Papanicolaou * At risk = new or multiple partners; diagnosis of gonorrhea or chlamydia within the last 12 months; those not consistently using barrier methods; those having sex under the influence of drugs Commercial sex workers; persons who exchange sex for drugs; incarceration in adult correctional facility; multiple sex partners * Increased risk defined as <25 years with inconsistent condom use; history of other STIs; multiple sex partners or drug use **** High-risk factors = history of multiple sex partners or a sex partner with multiple contacts; sexual contact with individuals with a culture-proven STI; history of repeated episodes of STIs; attendance at clinics for STIs

STI screening recommendations for pregnant women (STI/Syphilis) node 1192

STI screening recommendations for pregnant women

STI Screening Recommendations for Pregnant Women
STI	USPSTF	CDC	AAFP	ACOG
Chlamydia	Screen women <25 years and others at increased risk*	Screen all sexually active females ≤25 years and those >25 who are at risk**	Screen women ≤25 years and others at increased risk*	Screen women at increased risk***
Gonorrhea	Screen women <25 years and others at increased risk*	Screen women at increased risk**	Screen women at increased risk*	Screen women at increased risk***
Syphilis	Screen all	Screen all at first prenatal visit; retest in 3rd trimester for women at high risk	Screen all	Screen all
HIV	Screen all	Screen all at first prenatal visit; retest in 3rd trimester for women at high risk	Screen all	Screen all
Hepatitis B	Screen all	Screen all at first prenatal visit	Screen all	Screen all
Hepatitis C	No specific recommendation	Screen women at increased risk**	No specific recommendation	Screen women at increased risk***
HSV	Do not screen asymptomatic patients	No specific recommendation	Do not screen general population	No specific recommendation
HPV	No specific recommendation	No specific recommendation	No specific recommendation	No specific recommendation
Bacterial vaginosis	Do not screen for low-risk patients; insufficient evidence to recommend screening in patients at high risk for preterm delivery	No specific recommendation	Do not screen for low-risk patients; insufficient evidence to recommend screening in patients at high risk for preterm delivery	No specific recommendation
STI = sexually transmitted infection; USPSTF = U.S. Preventive Services Task Force; CDC = Centers for Disease Control and Prevention; AAFP = American Academy of Family Physicians; ACOG = American Congress of Obstetricians and Gynecologists; HIV = human immunodeficiency virus; HSV = herpes simplex virus; HPV = human papillomavirus; Pap = Papanicolaou * At risk = new or multiple partners; diagnosis of gonorrhea or chlamydia within the last 12 months; those not consistently using barrier methods; those having sex under the influence of drugs Increased risk = defined as <25 years with inconsistent condom use; history of other STIs; multiple sex partners or drug use * High-risk factors = history of multiple sex partners or a sex partner with multiple contacts; sexual contact with individuals with a culture-proven STI; history of repeated episodes of STIs; attendance at clinics for STIs

STI screening recommendations for men
- USPSTF (2004; reaffirmed 2016)
  - No screening if not engaging in high-risk behaviors
  - If engaging in high-risk behaviors, screen for syphilis and HIV
- CDC
  - Screen all men for HIV who seek medical care, and then at least annually
  - Routine annual screening recommended for men who have sex with men (MSM)
  - Syphilis serology at baseline
  - Urethral specimen for gonorrhea and chlamydia in men who have insertive intercourse
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 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

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.

Most common viral STIs
Most common bacterial STIs
- Chlamydia trachomatis
  Epidemiology
  
  Incidence – 643/100,000 for females; 262/100,000 for males (CDC, 2014); most common reportable STI in U.S. and worldwide
  
  Age – highest incidence in 15-24 yrs
  
  Gram-negative obligate intracellular parasite
  
  Risk Factors
  
  Multiple sex partners (≥2)
  
  Non-Caucasian
  
  Younger age (<25 yrs)
  
  Coinfection with gonorrhea or HIV
  
  Non-use of barrier methods
  
  Previous history of STI
  
  Clinical Presentation
  
  Asymptomatic in >50% of infected patients
  
  Urethritis, salpingitis, epididymo-orchitis
  
  Oropharyngeal disease
  
  Pelvic inflammatory disease (PID)
  
  Proctitis – predominantly in men having sex with men (MSM)
  
  Infection during pregnancy increases risk of
  Premature rupture of membranes
  
  Preterm delivery
  
  Low birth weight
  
  Neonatal conjunctivitis
  
  Neonatal pneumonia
  
  Complications
  Ectopic pregnancy
  
  Tubal factor infertility
  Bacterial vaginosis (BV)
  Epidemiology
  
  Prevalence – 10-30% of pregnant women (APA); most common form of vaginitis (≥50% of women with BV are asymptomatic)
  
  Caused by a combination of Gardnerella vaginalis with anaerobic bacteria overgrowth at the expense of commensal lactobacilli
  Polymicrobial
  
  Risk Factors
  
  Douching
  
  Non-use of barrier methods
  
  Multiple sex partners (>2)
  
  Non-Caucasian
  
  Clinical Presentation
  
  Malodorous vaginal discharge (fishy odor)
  
  Vulvovaginitis, cervicitis, salpingitis
  
  Infection during pregnancy increases risk of
  Acquisition and transmission of HIV
  
  Preterm labor
  
  Premature rupture of membranes
  
  Postpartum endometriosis
  Neisseria gonorrhoeae
  Epidemiology
  
  Incidence – 108/100,000 for females; 106/100,000 for males (CDC, 2014)
  
  Age – highest incidence in 15-24 yrs
  
  Nonmotile gram-negative diplococcus
  
  Risk Factors
  
  Multiple sex partners (>2)
  
  Non-Caucasian
  
  Younger age (<25 yrs)
  
  Coinfection with HIV
  
  Non-use of barrier methods
  
  Previous history of STI
  
  Douching
  
  Clinical Presentation
  
  Cervicitis, urethritis, salpingitis
  
  PID
  
  Oropharyngeal disease
  
  Neonatal infection
  
  Proctitis (predominantly in MSM)
- Treponema pallidum (syphilis)
Most-common parasitic/protozoan STI
- Trichomonas vaginalis
  Epidemiology
  
  Prevalence – ~3 million in U.S. (CDC, 2015)
  
  Age – highest incidence in 30-50 yrs
  
  Flagellated protozoan
  
  Risk Factors
  
  Multiple sex partners (>2)
  
  Non-Caucasian
  
  Coinfection with gonorrhea or HIV
  
  Non-use of barrier methods
  
  Previous history of STI
  
  Clinical Presentation
  
  >50% of women with T. vaginalis infections have minimal or no symptoms
  If symptomatic, T. vaginalis infections can cause vaginitis, urethritis, and cervicitis
  
  May present with malodorous vaginal discharge, strawberry cervix, dysuria, and vulvar irritation (accounts for 15-20% of cases of vulvovaginitis)
  
  Infection during pregnancy increases risk of
  HIV transmission
  
  Preterm labor
  
  Premature rupture of membranes
  
  Low birth weight

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.

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

Recommended Use

Preferred test for detecting C. trachomatis, N. gonorrhoeae, and T. vaginalis in variety of specimens

Refer to Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests for optimal specimen types and collection instructions

Panel includes C. trachomatis, N. gonorrhoeae, and T. vaginalis

Highly sensitive and specific

Limitations

Testing of oral and rectal specimens is not recommended

The performance of this test has not been evaluated in adolescents <14 years

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

Recommended Use

Detect C. trachomatis and N. gonorrhoeae in a variety of specimens

Positive results are confirmed using an alternate nucleic acid target

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) 0060241
Method: Qualitative Transcription-Mediated Amplification

Recommended Use

Preferred test for detecting C. trachomatis and N. gonorrhoeae in variety of specimens

Per 2014 CDC recommendations, this test does not include confirmation of positive results by an alternate nucleic acid target (NAAT); if confirmation of positive results by an alternate NAAT is required, please refer to C. trachomatis and N. gonorrhoeae by TMA with confirmation

Refer to Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests for optimal specimen types and collection instructions

Highly sensitive and specific

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), ThinPrep 0060734
Method: Transcription-Mediated Amplification

Recommended Use

Can be used to detect C. trachomatis and N. gonorrhoeae in ThinPrep specimens

Per 2014 CDC recommendations, this test does not include confirmation of positive results by an alternate NAAT; if confirmation of positive results by an alternate NAAT is required, please refer to C. trachomatis and N. gonorrhoeae by TMA with confirmation

For optimal sensitivity, vaginal swabs are recommended

Refer to Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests for optimal specimen types and collection instructions

Limitations

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

The performance of this test has not been evaluated in adolescents <16 years

Chlamydia trachomatis and Neisseria gonorrhoeae by Transcription-Mediated Amplification (TMA), SurePath 2001551
Method: Transcription-Mediated Amplification

Recommended Use

SurePath media is not preferred when testing for C. trachomatis and N. gonorrhoeae by TMA

Preferred test is C. trachomatis and N. gonorrhoeae by TMA or if confirmation of positive results by an alternate NAAT is required, refer to C. trachomatis and N. gonorrhoeae by TMA with confirmation

For optimal sensitivity, vaginal swabs collected and transported using the manufacturers’ collection kits are recommended

Refer to Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests for optimal specimen types and collection instructions

Limitations

Use of transport media other than APTIMA specimen collection kit may result in reduced sensitivity

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

The performance of this test has not been evaluated in adolescents <16 years

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

Recommended Use

Diagnose infection with T. vaginalis from genitourinary sources

Refer to Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests for optimal specimen types and collection instructions

Limitations

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

The performance of this test has not been evaluated in adolescents <14 years

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

Recommended Use

Preferred test for detecting C. trachomatis in a variety of specimens

Highly sensitive and specific

Refer to Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests for optimal specimen types and collection instructions

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

Recommended Use

Preferred test for detecting N. gonorrhoeae in a variety of specimens

Highly sensitive and specific

Refer to Sample Collection for the Diagnosis of STD Using Nucleic Acid Amplification Tests for optimal specimen types and collection instructions

Limitations

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

Chlamydia trachomatis Culture 0060850
Method: Cell Culture/Immunofluorescence

Recommended Use

Not recommended for routine detection of C. trachomatis

Use to detect C. trachomatis in medicolegal settings and to assess suspected treatment failure

May be considered for anatomic locations for which amplified testing has not been validated

High specificity

Limitations

Less sensitive than nucleic acid amplification tests

Two to three days required for results

Nucleic amplification testing is recommended for detection of C. trachomatis from endocervical or urethral specimens; refer to C. trachomatis by Transcription-Mediated Amplification (TMA)

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

Unusual Organism Culture 0060714
Method: Culture

Recommended Use

Order for organisms for which no stand-alone cultures are available; for example, S. monoiliformis, H. ducreyii, and others; N. gonorrhoeae specimens not approved for NAAT testing

Guidelines

Cantor AG, Pappas M, Daeges M, Nelson HD. Screening for Syphilis: Updated Evidence Report and Systematic Review for the US 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

Meyers D, Wolff T, Gregory K, Marion L, Moyer V, Nelson H, Petitti D, Sawaya GF, USPSTF. USPSTF recommendations for STI screening. Am Fam Physician. 2008; 77(6): 819-24. 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 [Accessed: Nov 2015]

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: Nov 2015]

U.S. Preventive Services Task Force. Screening for chlamydial infection: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2007; 147(2): 128-34. PubMed

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

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

Fisher, Mark A., PhD, D(ABMM), Medical Director, Bacteriology and Antimicrobials at ARUP Laboratories; Assistant Professor of Clinical Pathology, University of Utah

Schlaberg, Robert, MD, MPH, Medical Director, Microbial Amplified Detection, Virology, and Fecal Chemistry; and Assistant Medical Director, Virology and Molecular Infectious Disease at ARUP Laboratories; Assistant Professor of Clinical Pathology, University of Utah

Cervical Cancer

Herpes Simplex Virus - HSV

HSV Infection During Pregnancy Testing Algorithm

Human Immunodeficiency Virus - HIV

Human Papillomavirus - HPV

Septic Arthritis

Treponema pallidum - Syphilis

Spotlight on Test Utilization: STD screening in MSM - Importance of testing extra-genital sites -- Robert Schlaberg, MD, MPH

Last Update: August 2016

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Sexually Transmitted Infections

Indications for Testing

Laboratory Testing

Differential Diagnosis

STI screening recommendations for sexually active nonpregnant women (STI/Syphilis) node 1218

STI screening recommendations for pregnant women (STI/Syphilis) node 1192

Epidemiology

Risk Factors

Clinical Presentation

Epidemiology

Risk Factors

Clinical Presentation

Epidemiology

Risk Factors

Clinical Presentation

Epidemiology

Risk Factors

Clinical Presentation

Guidelines

General References

Medical Reviewers

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