Clinical update in sexually transmitted disease –2014
ABSTRACTSexually transmitted diseases (STDs) and their associated syndromes are extremely common in clinical practice. Early diagnosis, appropriate treatment, and partner management are important to ensure sexual, physical, and reproductive health in our patients.
KEY POINTS
- Anyone can have an STD, although the prevalence is higher in some groups, such as younger sexually active people, certain racial and ethnic minorities, men who have sex with men, and people who engage in risky sexual behavior.
- Preexposure vaccination is one of the most effective ways to prevent human papillomavirus, hepatitis A virus, and hepatitis B virus infections.
- The risk of acquiring human immunodeficiency virus is two to five times higher if the patient has a genital ulcerative disease such as syphilis or herpes at the time of exposure.
- Chlamydia trachomatis and Neisseria gonorrhoeae are major players in urethritis, cervicitis, and proctitis.
- The most common conditions associated with vaginitis include bacterial vaginosis, trichomoniasis, and candidiasis.
TRICHOMONIASIS: TREAT PARTNERS
Although most women with trichomoniasis have few or no symptoms, some have vaginal discharge that may be diffuse, malodorous, and yellow-greenish, and some have vulvar irritation.
Diagnosis of trichomoniasis: Microscopy is first-line but insensitive
The most common method for diagnosing T vaginalis infection remains microscopic evaluation of wet preparations of genital secretions, because of its convenience and relatively low cost. This may demonstrate the motile, flagellated protozoa T vaginalis and many white blood cells. Slides of vaginal fluid specimens should be examined immediately after collection to maximize performance. Unfortunately, the sensitivity of wet preparation is 44% to 80% in vaginal specimens.61
Culture is still considered the gold standard for diagnosing trichomoniasis and, if available, should be performed when direct microscopy is unrevealing.
Point-of-care diagnostic tests for T vaginalis infection include the OSOM Trichomonas Rapid Test (Sekisui Diagnostics, San Diego, CA), which is an immunochromatographic capillary flow dipstick test, and the Affirm VPIII (Becton, Dickinson and Company, Franklin Lakes, NJ), a nucleic acid probe-hydridization test that identifies T vaginalis, G vaginalis, and C albicans.44,62 Liquid-based Pap tests may demonstrate T vaginalis, although they should not be performed exclusively for this purpose. Among women, nucleic acid amplification tests may detect a prevalence three to five times higher than indicated by wet mount microscopy. The APTIMA Trichomonas vaginalis assay (Hologic Gen-Probe, San Diego, CA) was the most sensitive test for trichomonas detection in this study.63
Extragenital testing with nucleic acid amplification tests is not recommended for T vaginalis, as it remains unclear if the rectum can serve as a reservoir for infection, and T vaginalis has not been found to infect oral sites.8
Treatment of trichomoniasis: Metronidazole or tinidazole
Nitroimidazoles, ie, metronidazole and tinidazole, are the only class of drugs available to treat trichomoniasis. The recommended regimen is metronidazole or tinidazole 2 g orally in a single dose. Studies suggest that tinidazole may be superior to metronidazole, with higher cure rates due to its longer half-life and higher tissue concentrations.64
Low-level metronidazole resistance is estimated to occur in 2% to 5% of trichomoniasis infections65; high-level resistance occurs rarely. If a single dose of metronidazole 2 g fails to cure the infection and reinfection is ruled out, the patient should be treated with metronidazole 500 mg orally twice a day for 7 days. If this regimen is not effective, providers can consider tinidazole or metronidazole 2 g orally for 7 days.44,62,64 Consultation and susceptibility testing for T vaginalis is available from the CDC if these alternative regimens are ineffective.
T vaginalis infection has a high rate of transmission to sexual partners,66 and all partners should be treated. Male sexual partners should be treated with metronidazole 500 mg twice a day orally for 7 days, tinidazole 2 g orally in a single dose, or tinidazole 500 mg twice a day for 7 days. Patient-delivered partner therapy may have a role in partner management for trichomoniasis.67
PROCTITIS: SUSPECT LYMPHOGRANULOMA VENEREUM
Acute proctitis in men and women who practice receptive anal intercourse is usually sexually acquired. The most common causative organisms are N gonorrhoeae, C trachomatis (serotypes associated with or not associated with lymphogranuloma venereum), and HSV; T pallidum is less common.68 Co-infections are not uncommon in this setting.69
Symptoms of proctitis may include anal discharge, rectal ulcers and bleeding, anorectal pain, tenesmus, and constipation. Patients with lymphogranuloma venereum may also present with tender, fluctuant inguinal or femoral lymphadenopathy (buboes), or herpetiform genital ulcers or papules.
Diagnosis of proctitis
Clinical evaluation should include digital rectal examination and anoscopy (if possible) to look for abnormalities such as ulcerations, hemorrhoids, anal fissures, condylomas, strictures, exudate, and bleeding.
Appropriate diagnostic testing includes Gram staining and culture of discharge, herpes viral culture or PCR, and nucleic acid amplification testing for chlamydia and gonorrhea (in laboratories with Clinical Laboratory Improvement Amendments validation).8
Nucleic acid amplification tests detect C trachomatis serotypes L1–L3, responsible for lymphogranuloma venereum, and non-lymphogranuloma venereum serotypes A–K, but cannot distinguish between the two, whereas PCR-based genotyping can.8,26 Although this distinction is important to ensure appropriate evaluation and management of sex partners, empiric treatment for lymphogranuloma venereum (doxycycline 100 mg orally twice a day for 21 days) should be provided to patients at high risk, including men who have sex with men and who have anorectal chlamydia, HIV infection, or bloody discharge and perianal or mucosal ulcers.8
Treatment of proctitis
Patients with painful perianal or mucosal ulceration should receive presumptive treatment for lymphogranuloma venereum and HSV while awaiting results of diagnostic testing. If rectal discharge is detected or Gram staining of anorectal secretions detects polymorphonuclear leukocytes, treatment should include ceftriaxone 250 mg intramuscularly and doxycycline 100 mg orally twice a day for 7 days.8 Additional testing for syphilis and HIV should also be performed.
All sexual partners should be evaluated for any disease diagnosed in the index patient.
