Mycoplasma genitalium infection
Tully et al., 1983
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. ; Associate Editor(s)-in-Chief: Dima Nimri, M.D.  Mohamed Riad, M.D.
Mycoplasma genitalium infection is caused by the bacteria Mycoplasma genitalium. It was first isolated from 2 men with urethritis in the early 1980s, but was not recognized as a sexually transmitted disease until the early 1990s, following the development of polymerase chain reaction (PCR). Co-infection of Mycoplasma genitalium with other STDs is not uncommon. However, an isolated infection with Mycoplasma genitalium must be differentiated from other STDs, which may have a similar presentation. Mycoplasma genitalium infection is more common than Neisseria gonorrhea, but less common than Chlamydia trachomatis. However, it is not recognized as a common STD, largely because the infection is mostly asymptomatic. Symptoms are related to the complications it may cause, such as PID and cervicitis in women, and urethritis and epididymitis in men. Prompt antibiotic treatment is needed to prevent complications. Mycoplasma genitalium infection is prevented by promoting safe sexual practice, as well as the use of condoms.
- Mycoplasma genitalium is the 11th Mycoplasma species of human origin.
- In 1980, 13 men were tested for non-gonoccal urethritis (NGU). Mycoplasma genitalium was isolated from 2 of those 13 men.
- In the early 1990s, polymerase chain reaction (PCR) was developed, which allowed for diagnosis of Mycoplasma genitalium.
- Since 1993, the role of Mycoplasma genitalium as a cause of non-gonococcal urethritis has appeared in literature following the advances in polymerase chain reaction (PCR).
Mycoplasma genitalium infection can be divided based on the clinical presentation into:
- Asymptomatic Mycoplasma genitalium infection
- Symptomatic Mycoplasma genitalium infection: symptoms are related to PID or cervicitis in women and urethritis or epididymitis in men
Mode of Transmission
- Mycoplasma genitalium is recognized as a sexually transmitted disease (STD) with the mode of transmission being through direct genital-to-genital contact and subsequent inoculation of infected secretions. Transmission of Mycoplasma genitalium has also been implicated in penile-anal intercourse.
- Mycoplasma genitalium is less likely to be transmitted via oro-genital contact, as carriage in the oropharynx is low.
- Whether or not Mycoplasma genitalium is vertically transmitted from mother to newborn is yet to be studied. However, the bacterium has been isolated from the respiratory tract of newborns.
The incubation period of Mycoplasma genitalium is unknown yet.
The infectious dose of Mycoplasma genitalium is unknown yet.
Factors facilitating the pathogenesis of Mycoplasma genitalium
The following virulence factors have been implicated in the pathogenesis of Mycoplasma genitalium:
- Adhesion molecules: Mycoplasma genitalium has the ability to attach to different types of cells, including red blood cells, respiratory cells, fallopian tube cells, as well as sperm cells. It is believed that the attachment to sperm cells facilitates the spread of Mycoplasma genitalium to the female genital tract. MgPa, a major adhesion in attachment protein complex, facilitates not only adhesion to epithelial cells, but also the motility of Mycoplasma genitalium.
- Intracellular localization: Mycoplasma genitalium is a facultative intracellular organism and this allows for its survival both inside and outside of cells.
- Antigenic variation: Mycoplasma genitalium is able to generate surface lipoprotein with high frequency, which helps it evade the human immune system.
- Toxins: Mycoplasma genitalium has a calcium-dependent membrane associated nuclease known as MG-186. MG-186 is capable of degrading host cell nucleic acid, hence providing a source of nucleotides for the growth and pathogenesis of Mycoplasma genitalium.
- Enzymes: Glyceraldehyde 3-phosphate dehydrogenase (GADPH) acts as a ligand to the receptors mucin and fibronectin, found on vaginal and cervical epithelium.
- Immunological response: Mycoplasma genitalium possesses an immunogenic protein, MG-309, which secretes pro-inflammatory cytokines, such as IL-6 and IL-8. MG-309 exerts its effect via attaching to a toll-like receptor, hence activating nuclear factor kappa B (NF-kB)
There are no identified genetic factors associated with Mycoplasma genitalium infection.
Mycoplasma genitalium infection is associated with co-infection with other sexually transmitted diseases, such as:
- Chlamydia trachomatis
- Neisseria gonorrhea
- Trichomonas vaginalis
- HIV: Studies have reported an increased risk for HIV infection among women with Mycoplasma genitalium, evidenced by noticing that HIV shedding occurs more frequently among individuals with Mycoplasma genitalium and HIV infection who are not being treated than among individuals without this infection.
Gross pathology of Mycoplasma genitalium infection is related to the disease processes it may result: cervicitis, PID, urethritis, or epididymitis.
Microscopic pathology of Mycoplasma genitalium infection is related to the disease processes it may result: cervicitis, PID, urethritis, or epididymitis.
The cause of Mycoplasma genitalium infection is Mycoplasma genitalium.
Differentiating Mycoplasma genitalium Infection from Other Diseases
Mycoplasma genitalium infection must be distinguished from other sexually transmitted diseases, which may have a similar presentation. These include:
- Chlamydia trachomatis
- Neisseria gonorrhea
- Trichomonas vaginalis
- Ureaplasma urealyticum
- Herpes simplex virus
Epidemiology and Demographics
- The incidence and prevalence of Mycoplasma genitalium is not well established, because more than half of the women who tested positive were asymptomatic.
- In the United States, the prevalence of Mycoplasma genitalium was estimated as follows:
- The prevalence of Mycoplasma genitalium in all females aged 14-70 years old is 16.3%.
- The prevalence of Mycoplasma genitalium in all males aged 18-78 years old is 17.2%.
- Infection in both males and females was more prevalent in those younger than 30 years of age.
- The overall prevalence of Mycoplasma genitalium infection is 1%, which makes it more prevalent than Neisseria gonorrhea (0.4%), but less common than Chlamydia trachomatis (4.2%).
- Between the years 2002-2011, the prevalence of Mycoplasma genitalium worldwide ranged between 4%-42%.
- Mycoplasma genitalium is the cause of about 15%–20% of nongonococcal urethritis and 40% of persistent or recurrent urethritis.
- Rectal infection with Mycoplasma genitalium was detected in 1%–26% of men who had sex with men and among approximately 3% of women; however, rectal infections are usually asymptomatic.
- Macrolides resistance and treatment failure have been reported between 44% and 90% in the United States, Canada, Australia, and Western Europe due to frequent use of azithromycin as a single treatment for Mycoplasma genitalium.
There several risk factors that have been identified with Mycoplasma genitalium infection. These risk factors include:
- High risk sexual behavior, defined as having >3 new sexual partners in the past year
- Being engaged in sexual contact with persons with STDs, particularly Mycoplasma genitalium
- Non-white race
- Young age (<20 years old)
- Having less than high school education
- Having an annual income of less than $10,000
- Risk factors specific to females includes:
- Frequent douching
- Proliferative phase of the menstrual cycle
- History of spontaneous miscarriage
- Undergoing procedures that breach the cervical barrier
- Use of Depo-Provera for contraception
There are no recommendations for screening for Mycoplasma genitalium.
Natural history, Complications and Prognosis
If left untreated, Mycoplasma genitalium infection can lead to persistent cervicitis, PID, or urethritis.
The following complications may be the result of Mycoplasma genitalium infection:
- Complications in females include: cervicitis, endometritis, tubal factor infertility, pelvic inflammatory disease (PID), preterm labor as well as sexually active reactive arthritis (SARA).
- Complications in males include: epididymitis, urethritis, as well as sexually active reactive arthritis (SARA).
The prognosis of Mycoplasma genitalium infection is generally excellent. Cure rates are almost 100% with the correct and prompt antibiotic treatment.
History and Symptoms
The presenting symptoms of Mycoplasma genitalium are related to the disease processes it may cause. Presenting symptoms can be divided based on gender:
- Females: 40-75% of women infected with Mycoplasma genitalium are asymptomatic. However, when symptoms are present, they are usually related to the disease process Mycoplasma genitalium resulted. These include:
- Cervicitis: presents with vaginal discharge, vaginal itching, inter-menstrual, heavy or post-coital bleeding
- PID: presents with pelvic discomfort or lower abdominal pain, painful sexual intercourse (dyspareunia), vaginal discharge, and/or bleeding
- Urethritis: presents with pain on urination (dysuria) or urethral discharge
- Males: tend to be more symptomatic than females and present with symptoms of urethritis, which include urethral discharge and dysuria.
Physical examination findings in Mycoplasma genitalium are related to the disease processes it may cause. These findings can be divided based on the several disease pathologies in males and females.
- Cervicitis: findings include a purulent or mucopurulent cervical discharge, vaginal itching, inter-menstrual, heavy or post-coital bleeding
- PID: signs include lower abdominal tenderness, rebound tenderness, cervical motion, uterine or adnexal tenderness, vaginal discharge and/or bleeding and decreased bowel sounds
- Culture of Mycoplasma genitalium is not commonly used, as culture takes about 6 months to grow and is not widely available.
- Nucleic acid amplification test (NAAT) via polymerase chain reaction (PCR) or transcription-mediated amplification (TMA) is the preferred method for isolating Mycoplasma genitalium. Samples can be obtained from urine, urethral, vaginal or cervical swabs. However, first void urine sample is considered the best method for isolating the organism in both females and males.
- Males with recurrent nongonococcal urethritis as well as females with recurrent cervicitis or PID should be tested for Mycoplasma genitalium using NAAT. Resistance testing should be performed if available.
There is no role for x ray in Mycoplasma genitalium infection.
CT scan may be used if Mycoplasma genitalium infection has been complicated by PID. These include thickened and fluid-filled tubes with or without free pelvic fluid.
MRI may be used if Mycoplasma genitalium infection has been complicated by PID.
Other Diagnostic Studies
There are no other diagnostic studies for Mycoplasma genitalium infection.
Mycoplasma genitalium is intracellular and lacks the cell wall; hence, eradication of the organism is sometimes challenging. The antibiotic drug of choice and dosing depends on susceptibility of the Mycoplasma genitalium strain, and the availability of macrolides-resistance testing , as follows:
Recommended Regimens if Mycoplasma genitalium Resistance Testing Is Available
- If macrolide sensitive: Doxycycline 100 mg orally 2 times/day for 7 days, followed by azithromycin 1 g orally initial dose, followed by 500 mg orally daily for 3 additional days (2.5 g total)
- If macrolide resistant: Doxycycline 100 mg orally 2 times/day for 7 days followed by moxifloxacin 400 mg orally once daily for 7 days
Recommended Regimen if Mycoplasma genitalium Resistance Testing Is Not Available
Doxycycline 100 mg orally 2 times/day for 7 days, followed by moxifloxacin 400 mg orally once daily for 7 days
Surgical intervention is not recommended for the management of Mycoplasma genitalium infection.
Since Mycoplasma genitalium infection is a sexually transmitted disease, prevention must target safe sexual practices. These include:
- Practicing safe sex with one partner and avoiding multiple sexual partners
- Using condoms and/or other barrier methods
Secondary prevention in Mycoplasma genitalium infection consists of the following measures:
- Prompt treatment with antibiotics to prevent complications of the infection
- Test of cure is not recommended for asymptomatic individuals
- Partner notification and evaluation: if partner does not attend evaluation for infection, then he/she can be offered the same treatment as the patient
- Screening and treatment for other sexually transmitted diseases
- ↑ 1.0 1.1 Taylor-Robinson D, Jensen JS (2011). "Mycoplasma genitalium: from Chrysalis to multicolored butterfly". Clin. Microbiol. Rev. 24 (3): 498–514. doi:10.1128/CMR.00006-11. PMC 3131060. PMID 21734246.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 Jensen JS, Cusini M, Gomberg M, Moi H (2016). "Background review for the 2016 European guideline on Mycoplasma genitalium infections". J Eur Acad Dermatol Venereol. doi:10.1111/jdv.13850. PMID 27605499.
- ↑ 3.0 3.1 3.2 3.3 "Sexually Transmitted Diseases: Summary of 2015 CDC Treatment Guidelines". J Miss State Med Assoc. 56 (12): 372–5. 2015. PMID 26975162.
- ↑ 4.0 4.1 4.2 Manhart LE, Critchlow CW, Holmes KK, Dutro SM, Eschenbach DA, Stevens CE, Totten PA (2003). "Mucopurulent cervicitis and Mycoplasma genitalium". J. Infect. Dis. 187 (4): 650–7. doi:10.1086/367992. PMID 12599082.
- ↑ 5.0 5.1 5.2 Ross JD, Jensen JS (2006). "Mycoplasma genitalium as a sexually transmitted infection: implications for screening, testing, and treatment". Sex Transm Infect. 82 (4): 269–71. doi:10.1136/sti.2005.017368. PMC 2564705. PMID 16877571.
- ↑ 6.0 6.1 6.2 6.3 Falk L, Fredlund H, Jensen JS (2004). "Symptomatic urethritis is more prevalent in men infected with Mycoplasma genitalium than with Chlamydia trachomatis". Sex Transm Infect. 80 (4): 289–93. doi:10.1136/sti.2003.006817. PMC 1744873. PMID 15295128.
- ↑ 7.0 7.1 7.2 7.3 Jensen JS, Orsum R, Dohn B, Uldum S, Worm AM, Lind K (1993). "Mycoplasma genitalium: a cause of male urethritis?". Genitourin Med. 69 (4): 265–9. PMC 1195084. PMID 7721285.
- ↑ 8.0 8.1 8.2 8.3 Anagrius C, Loré B, Jensen JS (2005). "Mycoplasma genitalium: prevalence, clinical significance, and transmission". Sex Transm Infect. 81 (6): 458–62. doi:10.1136/sti.2004.012062. PMC 1745067. PMID 16326846.
- ↑ 9.0 9.1 9.2 Tosh AK, Van Der Pol B, Fortenberry JD, Williams JA, Katz BP, Batteiger BE, Orr DP (2007). "Mycoplasma genitalium among adolescent women and their partners". J Adolesc Health. 40 (5): 412–7. doi:10.1016/j.jadohealth.2006.12.005. PMC 1899169. PMID 17448398.
- ↑ 10.0 10.1 10.2 Korte JE, Baseman JB, Cagle MP, Herrera C, Piper JM, Holden AE, Perdue ST, Champion JD, Shain RN (2006). "Cervicitis and genitourinary symptoms in women culture positive for Mycoplasma genitalium". Am. J. Reprod. Immunol. 55 (4): 265–75. doi:10.1111/j.1600-0897.2005.00359.x. PMID 16533338.
- ↑ 11.0 11.1 Public Health Agency of Canada http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/mycoplasma-genitalium-eng.php Accessed on Oct 6, 2016.
- ↑ 12.0 12.1 Sethi S, Singh G, Samanta P, Sharma M (2012). "Mycoplasma genitalium: an emerging sexually transmitted pathogen". Indian J. Med. Res. 136 (6): 942–55. PMC 3612323. PMID 23391789.
- ↑ 13.0 13.1 Getman D, Jiang A, O'Donnell M, Cohen S (2016). "Mycoplasma genitalium Prevalence, Coinfection, and Macrolide Antibiotic Resistance Frequency in a Multicenter Clinical Study Cohort in the United States". J. Clin. Microbiol. 54 (9): 2278–83. doi:10.1128/JCM.01053-16. PMC 5005488. PMID 27307460.
- ↑ Vandepitte J, Weiss HA, Bukenya J, Kyakuwa N, Muller E, Buvé A; et al. (2014). "Association between Mycoplasma genitalium infection and HIV acquisition among female sex workers in Uganda: evidence from a nested case-control study". Sex Transm Infect. 90 (7): 545–9. doi:10.1136/sextrans-2013-051467. PMC 4215342. PMID :24687129 Check
- ↑ Manhart LE, Holmes KK, Hughes JP, Houston LS, Totten PA (2007). "Mycoplasma genitalium among young adults in the United States: an emerging sexually transmitted infection". Am J Public Health. 97 (6): 1118–25. doi:10.2105/AJPH.2005.074062. PMC 1874220. PMID 17463380.
- ↑ Taylor-Robinson D, Jensen JS (2011). "Mycoplasma genitalium: from Chrysalis to multicolored butterfly". Clin Microbiol Rev. 24 (3): 498–514. doi:10.1128/CMR.00006-11. PMC 3131060. PMID 21734246.
- ↑ Cina M, Baumann L, Egli-Gany D, Halbeisen FS, Ali H, Scott P; et al. (2019). "Mycoplasma genitalium incidence, persistence, concordance between partners and progression: systematic review and meta-analysis". Sex Transm Infect. 95 (5): 328–335. doi:10.1136/sextrans-2018-053823. PMC 6678058 Check
|pmc=value (help). PMID 31055469.
- ↑ Baumann L, Cina M, Egli-Gany D, Goutaki M, Halbeisen FS, Lohrer GR; et al. (2018). "Prevalence of Mycoplasma genitalium in different population groups: systematic review andmeta-analysis". Sex Transm Infect. 94 (4): 255–262. doi:10.1136/sextrans-2017-053384. PMC 5969327. PMID 29440466.
- ↑ Bachmann LH, Kirkcaldy RD, Geisler WM, Wiesenfeld HC, Manhart LE, Taylor SN; et al. (2020). "Prevalence of Mycoplasma genitalium Infection, Antimicrobial Resistance Mutations, and Symptom Resolution Following Treatment of Urethritis". Clin Infect Dis. 71 (10): e624–e632. doi:10.1093/cid/ciaa293. PMC 7744987 Check
|pmc=value (help). PMID 32185385 Check
- ↑ Pond MJ, Nori AV, Witney AA, Lopeman RC, Butcher PD, Sadiq ST (2014). "High prevalence of antibiotic-resistant Mycoplasma genitalium in nongonococcal urethritis: the need for routine testing and the inadequacy of current treatment options". Clin Infect Dis. 58 (5): 631–7. doi:10.1093/cid/cit752. PMC 3922211. PMID 24280088.
- ↑ Li Y, Su X, Le W, Li S, Yang Z, Chaisson C; et al. (2020). "Mycoplasma genitalium in Symptomatic Male Urethritis: Macrolide Use Is Associated With Increased Resistance". Clin Infect Dis. 70 (5): 805–810. doi:10.1093/cid/ciz294. PMC 7390511 Check
|pmc=value (help). PMID 30972419.
- ↑ Hancock EB, Manhart LE, Nelson SJ, Kerani R, Wroblewski JK, Totten PA (2010). "Comprehensive assessment of sociodemographic and behavioral risk factors for Mycoplasma genitalium infection in women". Sex Transm Dis. 37 (12): 777–83. doi:10.1097/OLQ.0b013e3181e8087e. PMC 4628821. PMID 20679963.
- ↑ United States Preventive Services Task Force https://www.uspreventiveservicestaskforce.org/BrowseRec/Search?s=mycoplasma+genitalium Accessed on Oct. 6, 2016.
- ↑ 24.0 24.1 Wetmore CM, Manhart LE, Lowens MS, Golden MR, Whittington WL, Xet-Mull AM, Astete SG, McFarland NL, McDougal SJ, Totten PA (2011). "Demographic, behavioral, and clinical characteristics of men with nongonococcal urethritis differ by etiology: a case-comparison study". Sex Transm Dis. 38 (3): 180–6. doi:10.1097/OLQ.0b013e3182040de9. PMC 4024216. PMID 21285914.
- ↑ Mena L, Wang X, Mroczkowski TF, Martin DH (2002). "Mycoplasma genitalium infections in asymptomatic men and men with urethritis attending a sexually transmitted diseases clinic in New Orleans". Clin. Infect. Dis. 35 (10): 1167–73. doi:10.1086/343829. PMID 12410476.
- ↑ 26.0 26.1 Falk L, Fredlund H, Jensen JS (2005). "Signs and symptoms of urethritis and cervicitis among women with or without Mycoplasma genitalium or Chlamydia trachomatis infection". Sex Transm Infect. 81 (1): 73–8. doi:10.1136/sti.2004.010439. PMC 1763725. PMID 15681728.
- ↑ 27.0 27.1 Gaydos C, Maldeis NE, Hardick A, Hardick J, Quinn TC (2009). "Mycoplasma genitalium as a contributor to the multiple etiologies of cervicitis in women attending sexually transmitted disease clinics". Sex Transm Dis. 36 (10): 598–606. doi:10.1097/OLQ.0b013e3181b01948. PMC 2924808. PMID 19704398.
- ↑ Short VL, Totten PA, Ness RB, Astete SG, Kelsey SF, Haggerty CL (2009). "Clinical presentation of Mycoplasma genitalium Infection versus Neisseria gonorrhoeae infection among women with pelvic inflammatory disease". Clin. Infect. Dis. 48 (1): 41–7. doi:10.1086/594123. PMC 2652068. PMID 19025498.
- ↑ Mobley VL, Hobbs MM, Lau K, Weinbaum BS, Getman DK, Seña AC (2012). "Mycoplasma genitalium infection in women attending a sexually transmitted infection clinic: diagnostic specimen type, coinfections, and predictors". Sex Transm Dis. 39 (9): 706–9. doi:10.1097/OLQ.0b013e318255de03. PMC 3428747. PMID 22902666.
- ↑ Tkach JR, Shannon AM, Beastrom R (1979). "Pseudofolliculitis due to preoperative shaving". AORN J. 30 (5): 881–4. doi:10.1016/s0001-2092(07)61393-3. PMID 259001.
- ↑ 31.0 31.1 Moi H, Reinton N, Moghaddam A (2009). "Mycoplasma genitalium in women with lower genital tract inflammation". Sex Transm Infect. 85 (1): 10–4. doi:10.1136/sti.2008.032748. PMID 18842689.
- ↑ Wiesenfeld HC, Sweet RL, Ness RB, Krohn MA, Amortegui AJ, Hillier SL (2005). "Comparison of acute and subclinical pelvic inflammatory disease". Sex Transm Dis. 32 (7): 400–5. PMID 15976596.
- ↑ Peipert JF, Ness RB, Blume J, Soper DE, Holley R, Randall H, Sweet RL, Sondheimer SJ, Hendrix SL, Amortegui A, Trucco G, Bass DC (2001). "Clinical predictors of endometritis in women with symptoms and signs of pelvic inflammatory disease". Am. J. Obstet. Gynecol. 184 (5): 856–63, discussion 863–4. doi:10.1067/mob.2001.113847. PMID 11303192.
- ↑ Horner PJ, Taylor-Robinson D (2011). "Association of Mycoplasma genitalium with balanoposthitis in men with non-gonococcal urethritis". Sex Transm Infect. 87 (1): 38–40. doi:10.1136/sti.2010.044487. PMID 20852310.
- ↑ Workowski KA, Bolan GA (2015). "Sexually transmitted diseases treatment guidelines, 2015". MMWR Recomm Rep. 64 (RR-03): 1–137. PMID 26042815.
- ↑ Huppert JS, Mortensen JE, Reed JL, Kahn JA, Rich KD, Hobbs MM (2008). "Mycoplasma genitalium detected by transcription-mediated amplification is associated with Chlamydia trachomatis in adolescent women". Sex Transm Dis. 35 (3): 250–4. doi:10.1097/OLQ.0b013e31815abac6. PMC 3807598. PMID 18490867.
- ↑ Högdahl M, Kihlström E (2007). "Leucocyte esterase testing of first-voided urine and urethral and cervical smears to identify Mycoplasma genitalium-infected men and women". Int J STD AIDS. 18 (12): 835–8. doi:10.1258/095646207782716983. PMID 18073017.
- ↑ Durukan D, Read TRH, Murray G, Doyle M, Chow EPF, Vodstrcil LA; et al. (2020). "Resistance-Guided Antimicrobial Therapy Using Doxycycline-Moxifloxacin and Doxycycline-2.5 g Azithromycin for the Treatment of Mycoplasma genitalium Infection: Efficacy and Tolerability". Clin Infect Dis. 71 (6): 1461–1468. doi:10.1093/cid/ciz1031. PMID 31629365.
- ↑ Li Y, Le WJ, Li S, Cao YP, Su XH (2017). "Meta-analysis of the efficacy of moxifloxacin in treating Mycoplasma genitalium infection". Int J STD AIDS. 28 (11): 1106–1114. doi:10.1177/0956462416688562. PMID 28118803.
- ↑ Mondeja BA, Couri J, Rodríguez NM, Blanco O, Fernández C, Jensen JS (2018). "Macrolide-resistant Mycoplasma genitalium infections in Cuban patients: an underestimated health problem". BMC Infect Dis. 18 (1): 601. doi:10.1186/s12879-018-3523-9. PMC 6264040. PMID 30486786.
- ↑ LeFevre ML. USPSTF: behavioral counseling interventions to prevent sexually transmitted infections. Ann Intern Med 2014;161:894–901.
- ↑ Warner L, Stone KM, Macaluso M, et al. Condom use and risk of gonorrhea and Chlamydia: a systematic review of design and measurement factors assessed in epidemiologic studies. Sex Transm Dis 2006;33:36–51.