The CDC recently updated their guidelines for STI treatment. The revised 2021 guidelines are accessible here.
What STI treatment recommendations will we cover?
- Chlamydia
- Gonorrhea
- Trichomoniasis
- Genital herpes (HSV-2)
- Syphilis
Chlamydia (Causative organism: C. trachomatis)
Chlamydia is one of the most common sexually transmitted infections in the United States. The person with Chlamydia is often without symptoms, regardless of birth gender assignment, a significant factor in transmission. The Centers for Disease Control and Prevention (CDC) estimate that less than 40% of the around 3 million annual cases are reported.
Recommended treatment:
- Doxycycline 100mg orally 2x/day for 7 days
- For pregnant individuals, azithromycin 1 gm orally in a single dose
Doxycycline has been shown to be more effective, especially with rectal presentation in which the single dose of azithromycin was clinically shown to not be sufficient. Doxycycline is also not a preferred drug for pregnant individuals due to its teratogenic potential.
Alternative treatment options:
- Azithromycin 1 gm orally in a single dose
- Azithromycin 500 mg orally in a single dose, then 250 mg orally 1x/day for 4 days
- Levofloxacin 500 mg orally 1x/day for 7 days
- In pregnancy, amoxicillin 500 mg orally 3x/day for 7 days
While there are specific recommendations for people living with HIV for some STIs, Chlamydia is not one of them. Individuals with HIV can receive the same treatment for Chlamydia.
Test-of-cure four weeks post-therapy is recommended for pregnancy, where symptoms persist, and where adherence to therapy is in question. However, note that the continued presence of nonviable organisms can lead to false-positive results for up to four weeks. Therefore, follow-up testing should not occur within this time frame.
Finally, because reinfection is common in individuals with recurring sex partners, patients should be retested three months after initial infection.
Recommended course: STIs: Latest CDC Treatment Recommendations
Gonorrhea (Causative organism: Neisseria gonorrhoeae)
Gonorrhea is the second most commonly reported bacterial STI, with an estimated 1.6 million new infections in the U.S. every year. Gonorrhea is one of the more symptomatic infections, resulting in urethritis, regardless of gender assignment, and vaginitis with purulent discharge.
When compared to Chlamydia, a person with N. gonorrhoeae infection is more likely to seek testing and treatment. Due to a rise in antibiotic resistance, gonorrhea treatment has changed significantly over the years.
Recommended treatment:
- Uncomplicated infections of the cervix, urethra, and/or rectum:
- If the patient weighs <150kg/330lbs: ceftriaxone 500 mg IM in a single dose
- If the patient weighs >150kg/330lbs: ceftriaxone 1 g IM in a single dose
- If a cephalosporin allergy is present:
- Gentamicin 240 mg IM in a single dose plus azithromycin 2 gm orally in a single dose
- If ceftriaxone administration is not available:
- Cefixime 800 mg orally in a single dose
The intramuscular (IM) dose is recommended in the ventrogluteal site. This has been shown to be safer than dorsogluteal due to the proximity of the dorsogluteal site to the sciatic nerve.
There is no dual therapy recommended if ceftriaxone is available, but it is recommended for gentamicin. It is also recommended to complete a test-of-cure 3-4 weeks out when gentamicin is used. It is not needed after treatment of genital and rectal infections unless symptoms persist a week after treatment. It is recommended 7-14 days after treatment for a pharyngeal infection.
Similar to chlamydia, reinfection is common in individuals with recurring sex partners. As such, patients should be retested approximately three months after treatment of the initial infection.
Trichomoniasis (Causative organism: Trichomoniasis vaginalis)
As with a number of other STIs, a change was made in the recommended treatment plan for trichomoniasis in females. A seven-day course of therapy was shown to be more efficacious than the formerly recommended single-dose option for the treatment in the female genital tract.
Recommended treatment:
- For females:
- Metronidazole 500 mg orally 2x/day for 7 days
- For males:
- Metronidazole 2 gm orally in a single dose
- Alternative for all patients:
- Tinidazole 2 gm orally in a single dose
Note that patients should be advised to avoid alcohol during these antibiotic courses and for 24 hours after completing metronidazole and 72 hours after taking tinidazole.
Genital Herpes (Causative organism: Herpes Simplex Type 2 Virus)
Recommended treatment
There have been no changes to the treatment recommendations for genital herpes (HSV-2). Treatment recommendations vary, with different doses and length of HSV-specific antiviral therapy, with initial outbreak, recurrent disease, and outbreak prevention. In order for the therapy to be optimally beneficial, the treatment ideally should begin within one day of the onset of symptoms.
- First episode/initial outbreak:
- Valacyclovir 1 gm orally 2x/day for 7-10 days
- OR acyclovir 400 mg orally 3x/day for 7-10 days
- OR famciclovir 250 mg orally 3x/day for 7-10 days
- Episodic:
- Valacyclovir 500 mg orally 2x/day for 3 days
- OR Valacyclovir 1 gm orally 1x/day for 5 days
- OR acyclovir 800 mg orally 2x/day for 5 days
- OR acyclovir 800 mg orally 3x/day for 2 days
- OR famciclovir 1 gm orally 2x/day for 1 day
- OR famciclovir 500 mg orally once, followed by famciclovir 250 mg orally 2x/day for 2 days
- OR famciclovir 125 mg orally 2x/day for 5 days
There is also a treatment regimen for HSV suppression. This should be offered for individuals with more frequent outbreaks or patients with psychological distress about the possibility of having outbreaks.
In addition, HSV suppression therapy benefits discordant sex partners by reducing the risk of transmission. Suppressive therapy during pregnancy does not eliminate the risk of perinatal transmission; however, it can reduce the risk of perinatal transmission.
- Suppressive:
- Acyclovir 400 mg orally 2x/day
- OR valacyclovir 500 mg orally 1x/day
Note that valacyclovir is less effective if the patient has more than 10 outbreaks a year. - OR valacyclovir 1 gm orally 1x/day
- OR famciclovir 250 mg orally 2x/day
- In pregnancy:
- Acyclovir 400 mg orally 3x/day
- OR valacyclovir 500 mg orally 2x/day
Finally, it is important for patients living with HIV to receive suppressive HSV treatment as links between the viruses have shown an increased risk of outbreaks and HIV transmission.
- Suppressive:
- Acyclovir 400-800 mg orally 2x-3x/day
- OR famciclovir 500 mg orally 2x/day
- OR valacyclovir 500 mg orally 2x/day
- Episodic:
- Acyclovir 400 mg orally 3x/day for 5-10 days
- OR famciclovir 500 mg orally 2x/day for 5-10 days
- OR valacyclovir 1 gm orally 2x/day for 5-10 days
Syphilis (Causative organism: Treponema pallidum)
There are four stages of syphilis disease, a systemic bacterial infection caused by the spirochete Treponema pallidum. Primary syphilis onset occurs around three weeks and lasts up to three months after the acquisition of the organism. The secondary stage lasts from 3 to 6 months. Early latent can be 6-12 months and late latent after that one year. With the right treatment, early syphilis is actually curable.
Recommended treatment:
- Primary, secondary, and early latent:
- Benzathine penicillin G 2.4 million units IM in a single dose
- Alternative treatments in the presence of penicillin allergy:
- Doxycycline 100 mg orally 2x/day for 14 days
- OR tetracycline 500 mg orally 4x/day for 14 days
- OR ceftriaxone 1 g IM or IV 1x/day for 10-14 days
- Late latent:
- Benzathine penicillin G 7.2 million units total administered as 3 doses of 2.4 million units IM at 1-week intervals
- Alternative treatments in the presence of penicillin allergy:
- Doxycycline 100 mg orally 2x/day for 4 weeks
- OR tetracycline 500 mg orally 4x/day for 4 weeks
- Serologic testing should be repeated at 6, 12, and 24 months
- Expert consultation advisable for neurosyphilis
The CDC provides specialized and detailed guidelines for syphilis treatment in the following cases:
- Tertiary syphilis
- Pregnancy
- Congenital
- Syphilis in people living with HIV/AIDS
Earn CE hours with the STIs: Latest CDC treatment recommendations online course (free with Passport Membership).
