By Stan Deresinski, MD, FACP, FIDSA

Clinical Professor of Medicine, Stanford University

SYNOPSIS: The Centers for Disease Control and Prevention has updated their recommendations for the treatment of several sexually transmitted infections, including gonorrhea, trichomoniasis, bacterial vaginosis, pelvic inflammatory disease, and those due to Chlamydia trachomatis and Mycoplasma genitalium.

SOURCE: Workowski KA, Bachmann LH, Chan PA, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep 2021;70:1-187.

The Centers for Disease Control and Prevention (CDC) has updated their 2015 guidelines for the treatment of sexually transmitted infections, and some of the changes are reviewed here.

Gonorrhea. Progressively reduced antibiotic susceptibility and concerns about altering the microbiome have led to a recommendation to discard dual therapy and instead to increase the dose of ceftriaxone monotherapy to a single 500-mg intramuscular (IM) dose (1,000 mg for individuals weighing > 150 kg). If ceftriaxone is unavailable, alternative regimens that can be used are a single 800-mg oral dose of cefixime or 500 mg IM gentamicin together with azithromycin 2 grams by mouth as single doses. Patients with pharyngeal infection should have a test of cure at seven to 14 days post-treatment.

Chlamydia trachomatis infection. The preferred treatment is doxycycline in a dose of 100 mg by mouth twice daily for seven days. Alternative regimens are azithromycin 1 gram orally as a single dose, which may be preferred for patients in whom adherence to a multidose regimen may be problematic, or levofloxacin 500 mg orally daily for seven days. If single-dose azithromycin is used, a test of cure should be considered at four weeks, at least in cases of rectal infection.

Pelvic inflammatory disease (PID). Empiric treatment of PID required coverage against Chlamydia trachomatis, Neisseria gonorrhoeae, and other likely pathogens, including anaerobes, with the last consideration leading to a recommendation to add metronidazole to all regimens. Thus, the currently recommended regimen is single-dose ceftriaxone (1,000 mg IM) together with doxycycline (100 mg orally twice daily for 14 days) and metronidazole (500 mg orally twice daily for 14 days).

Trichomoniasis. Although there has been no change in the recommendation of metronidazole given as a single oral dose of 2 grams to men, the recommendation for females now is 500 mg twice daily for seven days with the aim of reducing persistent infections. Tinidazole as a single 2-gram oral dose is an alternative treatment for both males and females.

Mycoplasma genitalium infection. Infection with this organism can be documented by a Food and Drug Administration (FDA)-approved nucleic acid amplification test (NAAT), but its treatment is complicated by increasing antimicrobial resistance in the face of frequent unavailability of resistance testing. If antimicrobial susceptibility is unknown because of unavailability of such testing, the CDC recommends doxycycline 100 mg orally twice daily for seven days, followed by moxifloxacin 400 mg once daily for seven days. If testing is available and the organism is susceptible to macrolides, the recommended regimen is doxycycline 100 mg orally two times/day for seven days, followed by azithromycin 1 g orally initial dose, followed by 500 mg orally once daily for three additional days (2.5 g total). If it is resistant to macrolide antibiotics instead, doxycycline 100 mg orally two times/day for seven days, followed by moxifloxacin 400 mg orally once daily for seven days.

Bacterial vaginosis. The CDC lists three preferred regimens from which to choose: metronidazole 500 mg orally twice daily for seven days, or metronidazole gel 0.75% one full applicator (5 g) intravaginally once a day for five days, or clindamycin cream 2% one full applicator (5 g) intravaginally at bedtime for seven days.


In addition to these antimicrobial treatment recommendations, the CDC provides additional statements regarding epidemiology, vaccination, and testing for various sexually transmitted infections. These include an expanded list of risk factors that direct testing for syphilis in pregnancy, alignment of their recommendations for human papillomavirus vaccination with those of the Advisory Committee on Immunization Practices, recommendation of universal hepatitis C virus testing, and serologic testing for diagnosis of genital herpes simplex infection.

The number of reported cases of sexually transmitted disease reached a new high for the sixth consecutive year in 2019 and, despite the appearance of COVID-19, the CDC reported a few months ago that “preliminary data suggest that many of these concerning trends continued in 2020, when much of the country experienced major disruptions to sexually transmitted disease testing and treatment services due to the COVID-19 pandemic.”1 


  1. Centers for Disease Control and Prevention. Reported STDs reach all-time high for 6th consecutive year. April 13, 2021.