EXECUTIVE SUMMARY
The WHO has issued new guidelines for the treatment of chlamydia, gonorrhea, and syphilis in response to the growing threat of antibiotic resistance.
- According to the international health organization, each year, 131 million people are infected with chlamydia, 78 million are infected with gonorrhea, and 5.6 million are infected with syphilis.
- Antibiotic resistance of these STIs has grown in recent years, which has limited treatment options. Neisseria gonorrhoeae, the bacteria that cause gonorrhea, has developed resistance to nearly all of the antibiotics used for treatment. Cephalosporins are the last effective class of antibiotics available to treat the infection.
The World Health Organization (WHO) has issued new guidelines for the treatment of chlamydia, gonorrhea, and syphilis in response to the growing threat of antibiotic resistance. According to the international health organization, each year, 131 million people are infected with chlamydia, 78 million are infected with gonorrhea, and 5.6 million are infected with syphilis.1
Antibiotic resistance of these STIs has grown in recent years, limiting treatment options. Neisseria gonorrhoeae, the bacteria that cause gonorrhea, has developed resistance to nearly all of the antibiotics used for treatment: sulfonamides, penicillin, tetracycline, and fluoroquinolones, such as ciprofloxacin. Cephalosporins are the last effective class of antibiotics available to treat the infection. (Contraceptive Technology Update reported on the issue. See “Are Antibiotics Overprescribed for Possible STIs? Check Your Practice” in the September 2016 STI Quarterly supplement at http://bit.ly/2d0YY30.)
The new WHO guidance does not recommend quinolones for the treatment of gonorrhea due to widespread high levels of resistance. It advises national health authorities to track the prevalence of resistance to different antibiotics in the strains of gonorrhea circulating among their population and to advise clinicians to prescribe whichever antibiotic would be most effective, based on local resistance patterns. It advises a dual therapy approach, using ceftriaxone 250 mg intramuscular (IM) as a single dose PLUS azithromycin 1 g orally as a single dose, OR cefixime 400 mg orally as a single dose PLUS azithromycin 1 g orally as a single dose. (Readers can review the guidance at http://bit.ly/2bzsTNq.)
To treat syphilis, the WHO recommends a single dose of benzathine penicillin administered as an injection in the buttock or thigh muscle. The WHO considers it to be the most effective treatment for syphilis, as it is more effective and cheaper than oral antibiotics. (Readers can access the WHO guidance online at http://bit.ly/2chbEnC.)
Due to recent shortages of benzathine penicillin, WHO is working with partners to identify countries with shortages and help monitor global availability to close the gap between national needs and supply of the antibiotic.
To treat chlamydia, the WHO advises the use of azithromycin, 1 g orally as a single dose, or doxycycline, 100 mg orally twice a day for seven days. When a high value is placed on reducing costs, doxycycline in a standard dose may be the best choice, the guidance notes; however, when convenience is of utmost concern, azithromycin in a single dose may be the best choice. (The guidance is available at http://bit.ly/2czVFl4.)
The U.S. Approach
The CDC reiterated its guidance for treatment of gonorrhea, which is a combination approach consisting of an oral dose of azithromycin and a single shot of ceftriaxone, following data indicating that the percentage of gonorrhea isolates with decreased susceptibility to azithromycin increased more than 300% between 2013 and 2014.2
The confluence of emerging drug resistance and very limited alternative options for treatment of gonorrhea creates a “perfect storm” for future gonorrhea treatment failure in the United States, notes Jonathan Mermin, MD, director of the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and Tuberculosis Prevention. “History shows us that bacteria will find a way to outlast the antibiotics we’re using to treat it,” said Mermin in a press statement accompanying the data release. “We are running just one step ahead in order to preserve the remaining treatment option for as long as possible.”
The combination therapy recommended by the CDC still works. No treatment failures have been reported to date in the United States. However, signs of emerging azithromycin resistance suggest that it will become ineffective against the bacteria that cause gonorrhea. Because of the STI’s ability to outsmart the antibiotics used to treat it, the CDC is keeping a close eye on early warning signs of resistance, not only to azithromycin but also to cephalosporins, the class of antibiotics that includes ceftriaxone.
Gail Bolan, MD, director of the CDC’s Division of STD Prevention, says, “It is unclear how long the combination therapy of azithromycin and ceftriaxone will be effective if the increases in resistance persist. We need to push forward on multiple fronts to ensure we can continue offering successful treatment to those who need it.”
Chlamydial infection is the most frequently reported infectious disease in the United States, with prevalence highest in those age 24 or younger.3 The 2015 STD Guidelines call for treatment with azithromycin, 1 g orally in a single dose, OR doxycycline, 100 mg orally, twice a day for seven days.4
For syphilis, the CDC notes that a single intramuscular injection of long-acting penicillin G benzathine (2.4 million units administered intramuscularly) will cure a person who has primary, secondary, or early latent syphilis.4 Pfizer Injectables of Lake Forest, IL, the sole manufacturer of Bicillin L-A (penicillin G benzathine) in the United States, is experiencing a manufacturing delay of this product. The CDC is working with FDA’s Drug Shortage Staff and Pfizer to address this situation. (To check the status, go to the FDA’s site at http://bit.ly/2d3ccii.)
REFERENCES
- World Health Organization. Sexually transmitted infections. Fact sheet. Accessed at http://www.who.int/mediacentre/factsheets/fs110/en.
- Kirkcaldy RD, Harvey A, Papp JR, et al. Neisseria gonorrhoeae antimicrobial susceptibility surveillance — The Gonococcal Isolate Surveillance Project, 27 sites, United States, 2014. MMWR Surveill Summ 2016; 65(No. SS-7):1-19.
- CDC. Sexually Transmitted Disease Surveillance 2013. Atlanta: Department of Health and Human Services; 2014.
- CDC. Sexually transmitted diseases treatment guidelines, 2015. MMWR Recomm Rep 2015; 64(No. RR-3): 1-137.
