Ramiro J. Madden-Fuentes, MD
Judd W. Moul, MD, FACS
BASICS
DESCRIPTION
• Sexually transmitted infections (STIs) are viral, bacterial, or parasitic disease typically transmitted via exposure to infected secretions or infested genitalia.
– Transmission is predominantly via sexual contact.
– Nonsexual transmission: Mother–infant, blood transfusions, accidental needle injury.
– STIs has generally replaced the term Sexually Transmitted Diseases (STDs)
EPIDEMIOLOGY
Incidence
• 20 million new infections yearly (1)[A]
– Relative frequency of cases by disease: HPV > Chlamydia > Trichomonas > Gonorrhea > HSV-2 > syphilis > HIV > Hep B
– 50% of new STIs in patients 15–24 yr old
Prevalence
• 110 million STIs estimated by the Centers for Disease Control and Prevention (CDC) (1)[A]
– Most prevalent STI is human papilloma virus (HPV)
– 25% STIs are incurable (HIV, HSV-2, Hep B)
RISK FACTORS
• Multiple sex partners, sexual contact with infected partner, unprotected sex
• Low socioeconomic status, drug abuse
• Exposure at delivery and/or in utero
Genetics
• CCR5 mutation provides relative protection against HIV infection (2)[C]
PATHOPHYSIOLOGY
• Ulcerative lesions
– HSV-1 and HSV-2
Type 1: 85–90% of genital cases
Type 2: 10–15% usually oral to genital contact
Painful ulcer of genitalia or anus and concomitant painful inguinal lymphadenopathy
Prodrome (initial infection and recurrent flares): Flu-like symptoms
– Chancroid (Haemophilus ducreyi)
Painful ulcer; tender inguinal adenopathy, suppurative with fistula to the skin
– Syphilis (Treponema pallidum)
Primary syphillis presents with painless ulcer, may last 4–6 wk. ± nontender adenopathy if untreated
Secondary syphillis presents with maculopapular rash of body and arms (including palms and soles of feet). If untreated 1/3 progress to 3° syphilis
Tertiary syphillis can affect any organ and can lead to aortitis, eye involvement, meningitis, spinal column (tabes dorsalis), and skin gummas
– Granuloma inguinale (Klebsiella granulomatis or Donovanosis)
Painless ulcer without lymphadenopathy
Intracellular Donovan bodies (hairpin intracellular inclusions)
– Lymphogranuloma venereum (LGV: Chlamydia trachomatis types L1–L3)
Transient genital ulcer
Tender inguinal/femoral lymphadenopathy
If untreated, may progress to a systemic infection or secondary bacterial infection
• Urethritis/cervicitis
– Neisseria gonorrhea
May present as urethritis, epididymitis, proctitis, or prostatitis
Male: Purulent discharge, dysuria
Female: Usually asymptomatic, but may have pelvic discomfort, dysuria, dyspareunia
– Nongonococcal (C. trachomatis, Mycoplasma, Ureaplasma urealyticum)
Chlamydia: Frequently asymptomatic, may present with urethritis, epididymitis, or prostatitis. Gonorrhea may coexist
25% of women are symptomatic, and can have a mucopurulent cervical discharge
40% of untreated women will develop pelvic inflammatory disease (PID). PID is associated with infertility and ectopic pregnancy
• Vaginal discharge
– Trichomonas vaginalis
Male: Presents with urethritis but often asymptomatic
Female: Malodorous, yellow-green vaginal discharge with vulvar irritation
• Genital warts
– Condyloma acuminata (HPV)
HPV 6 and 11 tend to cause warts, HPV 16, 18, 31, 33, and 35 are high risk for cellular dysplasia and increase cancer risk
– Condyloma lata (T. pallidum)
Occurs in 10% of patients with 2° syphilis.
Moist, broad, wart-like, highly infectious lesions that may ulcer
• Parasites
– Pubic lice (Phthirus pubis)
Presents with genital pruritus, insects may be visible on hair or clothing
– Scabies (Sarcoptes scabiei)
Mites burrow under skin and lay eggs, pruritus results from an inflammatory reaction to excreta
ASSOCIATED CONDITIONS
• Coinfection is common (ie, gonorrhea and chlamydia)
• HPV may be associated with carcinomas (cervical, penile, vulvar)
• PID: (Chlamydia and gonorrhea), infertility, tuboovarian abscess, Fitz-Hugh–Curtis syndrome
• Reiter syndrome: HLA B27
• Septic arthritis: Disseminated gonococcal infection
GENERAL PREVENTION
• Abstinence
• Female and male condoms
• Education and awareness of risky behavior
• HPV vaccine (Cervarix—against HPV 16, 18; Gardasil—against HPV 6, 11, 16, 18) (3)[A]
DIAGNOSIS
HISTORY
• Symptoms, duration, onset, quality, severity, related conditions
– Especially: Dysuria, dyspareunia, urethral discharge, genital lesions
• Screen for IV drug use, drug/alcohol abuse
• Sexual history: Prior STIs, number partners, use of protection
ALERT
Rule out sexual abuse in children with a potential STI.
PHYSICAL EXAM
• Vitals: Fever, tachycardia
• Skin: Maculopapular rash (syphilis), examine soles and palms, linear burrows (scabies)
• Cardiac: Murmur (aortic insufficiency—syphilis)
• Abdomen: Tenderness, rebound, guarding
• GU: Ulcerations, vesicles, urethral discharge, warts (GU and anal)
• Pelvic: Cervical tenderness, petechial hemorrhages (Trichomonas), uterine tenderness
• Neuro: Tabes dorsalis, Argyll Robertson pupil (syphilis)
DIAGNOSTIC TESTS & INTERPRETATION
Lab
• HSV (3)[A]
– Growth of HSV in culture with serologic subtyping is gold standard
– PCR assay for HSV DNA most sensitive for diagnosis: FDA approved only for vaginal swabs in symptomatic women
– Cytologic detection (Tzanck smear) is not sensitive and should not be relied upon
• Syphilis (3)[A]
– Dark field microscopy or direct fluorescence antibody of lesion exudate is diagnostic
– Serologic: Nonspecific treponemal test
Rapid plasma reagin (RPR) and venereal disease research laboratory (VDRL): Sensitivity is ∼80% in primary syphilis, 100% in secondary, and over 95% in tertiary syphilis
Must confirm with a specific treponemal test
Will revert to normal after therapy
– Serologic: Specific treponemal test
FTA-ABS (fluorescent treponemal antibody absorbed) and TP-PA (T. pallidum particle agglutination)—detects antibodies against spirochetes
Positive for life
• HIV (3)[A]
– ELISA (an enzyme immunoassay): Rapid, sensitivity—99.7%, specificity—98.5%
– Confirm ELISA + results by Western blot
• Chlamydia/Gonorrhea (3)[A]
– Nucleic acid amplified test (NAAT) of urine: 1st 10–30 cc voided
– Culture: Gonorrhea in Thayer–Martin or chocolate agar
• LGV: Swab lesion or aspirate node for culture (3)[A]
• Chancroid (3)[A]
– H. ducreyi can be grown on culture, although sensitivity is <80%
– PCR is available, but not FDA approved
• Granuloma inguinale (3)[A]
– Difficult to culture; requires visualization of dark-staining Donovan bodies in sample
• Trichomonas (3)[A]
– Wet prep reveals flagellated protozoans
– In men, wet prep not sensitive: Thus, culture urine, urethral swab, or semen
• Pubic lice/scabies
– Detectable on low-power microscopy
Imaging
N/A
Diagnostic Procedures/Surgery
• HPV: Aceto-white test for occult disease
– 3–5% acetic acid (white vinegar) application to HPV-infected mucosa turns white
– Questionable utility: Not validated
Pathologic Findings
See “Lab” section
DIFFERENTIAL DIAGNOSIS
• Genital ulcer mnemonic CHISEL
– Chancroid (painful)
– Herpes genitalis (painful)
– Inguinale (granuloma inguinale)
– Syphilis (painless)
– Eruption secondary to drugs
– LGV
• Genital ulcer: Other causes
– Behçet disease
– Excoriations
– Fixed drug eruption
– Genital trauma
– Pyoderma
– Scabies
• Urethral discharge
– Gonorrhea
– Nongonococcal urethritis: C. trachomatis (35–45%), Ureaplasma urealyticum (15–25%), Trichomonas vaginalis
• Nonulcerative STDs
– PID: C. trachomatis, N. gonorrhea, Mycoplasma hominis, facultative or anaerobic organisms
– Syphilis (secondary/tertiary)
– HIV, hepatitis B and C
TREATMENT
GENERAL MEASURES
• Screen for coinfection (including HIV)
• Educate for prevention of transmission
• Screen partner
MEDICATION
First Line
• HSV: Acyclovir 400 mg PO TID for 7–10 days, or famciclovir 250 mg PO TID for 7–10 days, or valacyclovir 1 g PO BID for 7–10 days (3)[A]
• Chancroid: Azithromycin 1 g PO in 1 dose or ceftriaxone 250 mg IM in 1 dose
• Syphilis
– Primary: Benzathine penicillin G 2.4 million units IM in 1 dose
– Latent: Early—benzathine penicillin G 2.4 million units IM once. Late—Benzathine penicillin G 2.4 million units IM weekly × 3 wk
– Tertiary: Nonneurosyphilis - benzathine penicillin G 2.4 million units IM weekly × 3 wk. Neurosyphilis—aqueous crystalline penicillin G, 3–4 million units IV q4h for 10–14 days
• Granuloma Inguinale: Doxycycline 100 mg PO BID for 21 days or until all lesions are healed
• LGV: Doxycycline 100 mg PO BID for 3 wk
• Gonorrhea: Ceftriaxone 250 mg IM in 1 dose, or cefixime 400 mg PO in 1 dose; also treat for Chlamydia
• Chlamydia: Azithromycin 1 g PO in 1 dose or doxycycline 100 mg PO BID for 7 days
• Trichomoniasis: Metronidazole 2 g PO 1 dose
• Genital warts (condyloma)
– Observation
– Podofilox 0.5% solution or gel (lesion <10 cm) q12h for 3 days then off for 4 days; cycle may be repeated 4 times
• Pubic lice: Permethrin cream (1%) to affected areas and washed off after 10 min
Second Line
Please refer to the CDC’s published Sexually Transmitted Diseases Treatment Guidelines 2010 for updates and alternatives
SURGERY/OTHER PROCEDURES
• Surgical intervention may be necessary secondary to complications from STIs
– Urethritis: Urethral stricture
– Gonorrhea/chlamydia: PID (tuboovarian abscess, ectopic pregnancy)
– HIV: Kaposi sarcomas
– Genital warts (condyloma): Ablation with laser, electrosurgery
ADDITIONAL TREATMENT
Radiation Therapy
N/A
Additional Therapies
N/A
Complementary & Alternative Therapies
N/A
ONGOING CARE
PROGNOSIS
• Many STIs cured with treatment
• HSV: Outbreaks reduced by prophylactic therapies
• HIV: Medical management portends long survival
COMPLICATIONS
Urethral stricture, carcinomas, PID, infertility, neurologic, and cardiovascular disease
FOLLOW-UP
Patient Monitoring
Screen nonpregnant females <25 yr old for gonorrhea/chlamydia. Screen nonpregnant females with risky behavior for gonorrhea/chlamydia/HIV/syphilis (4)[A]
Patient Resources
CDC. http://www.cdc.gov/std
REFERENCES
1. Satterwhite CL, Torrone E, Meites E, et al. Sexually transmitted infections among U.S. women and men: Prevalence and incidence estimates, 2008. Sex Transm Dis. 2013;40(3):187–193.
2. Liu R, Paxton WA, Choe S, et al. Homozygous defect in HIV-1 coreceptor accounts for resistance of some multiply-exposed individuals to HIV-1 infection. Cell. 1996;86(3):367–377.
3. Workowski KA, Berman S. Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2010. MMWR Recomm Rep. 2010;59(RR-12):1–110.
4. Meyers D, Wolff T, Gregory K, et al. USPSTF Recommendations for STI Screening. Am Fam Physician. 2008;77:819–824.
ADDITIONAL READING
N/A
See Also (Topic, Algorithm, Media)
• Genital Ulcers
• Lymphadenopathy, Inguinal
• Sexually Transmitted Infections (STI) (Sexually Transmitted Diseases [STD]), General Images 
• See Section I and Section II “Specific STD/STI"
• Urethra, Discharge
CODES
ICD9
• 042 Human immunodeficiency virus [HIV] disease
• 099.41 Other nongonococcal urethritis, chlamydia trachomatis
• 099.9 Venereal disease, unspecified
ICD10
• A56.8 Sexually transmitted chlamydial infection of other sites
• A64 Unspecified sexually transmitted disease
• B20 Human immunodeficiency virus [HIV] disease
CLINICAL/SURGICAL PEARLS
• When treating gonorrhea treat for chlamydia as these often coexist.
• HPV vaccine recommended for Either HPV vaccine is recommended (by the CDC) for 11–12-year-old girls. Quadrivalent HPV vaccine is recommended for 11–12-year-old boys. Start series at age 9 years. Vaccination is also recommended for 13–26-year-old females and13–21-year-old males who have not completed the vaccine series. Quadrivalent HPV vaccine may be given to 22–26-year-old males and is routinely recommended for both men who have sex with men (MSM) and immunocompromised persons aged 22 through 26 years.
• Urethritis may lead to urethral stricture in males.