In the JournalsPerspective

Canada finds case of ceftriaxone-resistant gonorrhea

A three-dimensional computer-generated image of drug-resistant Neisseria gonorrhoeae diplococcal bacteria.
This is a computer-generated image of drug-resistant gonorrhea. A woman in Canada was diagnosed this year with a gonorrhea infection that was resistant to ceftriaxone, one of the last remaining drugs available to treat the STD.
Source: CDC

A patient in Canada was diagnosed this year with a gonorrhea infection that was resistant to ceftriaxone, one the last available treatments for the increasingly drug-resistant STD.

Ceftriaxone is one of only two drugs recommended by WHO and the CDC to treat gonorrhea, the other being azithromycin. The same dual therapy is recommended in Canada.

Many countries have seen resistance to both drugs, leading to warnings about the emergence of potentially untreatable gonorrhea. In Seattle, enough gonorrhea infections have demonstrated reduced susceptibility to azithromycin that researchers have wondered if it should remain a recommended treatment.

According to Brigitte Lefebvre, PhD, of the National Institute of Public Health of Quebec, and colleagues, the Canadian case was only the sixth ceftriaxone-resistant Neisseria gonorrhoeae isolate reported in the world as of Oct. 15. It was the first such case reported in North America.

Writing in Emerging Infectious Diseases, Lefebvre and colleagues said the patient, a woman aged 23 years, was asymptomatic when she tested positive for gonorrhea during an STD screening on Jan. 17. Seven days later, she was prescribed cefixime and azithromycin during a follow-up visit to an STD clinic.

A culture performed during the follow-up visit showed the infection was resistant to ceftriaxone and cefixime but susceptible to azithromycin, according to Lefebvre and colleagues. The patient tested negative for gonorrhea 2 weeks later, indicating that treatment with cefixime and azithromycin worked, they said.

The patient’s two most recent sexual partners — including one who reported unprotected sexual activity during a trip to China and Thailand just before the relationship — each tested negative for gonorrhea. Genetic testing of the woman’s infection showed it was identical to a ceftriaxone- and multidrug-resistant isolate from Japan, suggesting that it spread from Asia, Lefebvre and colleagues said.

“Antimicrobial susceptibility surveillance successfully identified this novel isolate introduced into Canada and prompted public health officials to rapidly conduct an investigation to prevent further spread in the community,” they wrote. “In an era of multidrug-resistant gonorrhea, ongoing antimicrobial susceptibility surveillance of N. gonorrhoeae is critical to support treatment guidelines, public health intervention and protection.” - by Gerard Gallagher

Disclosure: The authors report no relevant financial disclosures.

A three-dimensional computer-generated image of drug-resistant Neisseria gonorrhoeae diplococcal bacteria.
This is a computer-generated image of drug-resistant gonorrhea. A woman in Canada was diagnosed this year with a gonorrhea infection that was resistant to ceftriaxone, one of the last remaining drugs available to treat the STD.
Source: CDC

A patient in Canada was diagnosed this year with a gonorrhea infection that was resistant to ceftriaxone, one the last available treatments for the increasingly drug-resistant STD.

Ceftriaxone is one of only two drugs recommended by WHO and the CDC to treat gonorrhea, the other being azithromycin. The same dual therapy is recommended in Canada.

Many countries have seen resistance to both drugs, leading to warnings about the emergence of potentially untreatable gonorrhea. In Seattle, enough gonorrhea infections have demonstrated reduced susceptibility to azithromycin that researchers have wondered if it should remain a recommended treatment.

According to Brigitte Lefebvre, PhD, of the National Institute of Public Health of Quebec, and colleagues, the Canadian case was only the sixth ceftriaxone-resistant Neisseria gonorrhoeae isolate reported in the world as of Oct. 15. It was the first such case reported in North America.

Writing in Emerging Infectious Diseases, Lefebvre and colleagues said the patient, a woman aged 23 years, was asymptomatic when she tested positive for gonorrhea during an STD screening on Jan. 17. Seven days later, she was prescribed cefixime and azithromycin during a follow-up visit to an STD clinic.

A culture performed during the follow-up visit showed the infection was resistant to ceftriaxone and cefixime but susceptible to azithromycin, according to Lefebvre and colleagues. The patient tested negative for gonorrhea 2 weeks later, indicating that treatment with cefixime and azithromycin worked, they said.

The patient’s two most recent sexual partners — including one who reported unprotected sexual activity during a trip to China and Thailand just before the relationship — each tested negative for gonorrhea. Genetic testing of the woman’s infection showed it was identical to a ceftriaxone- and multidrug-resistant isolate from Japan, suggesting that it spread from Asia, Lefebvre and colleagues said.

“Antimicrobial susceptibility surveillance successfully identified this novel isolate introduced into Canada and prompted public health officials to rapidly conduct an investigation to prevent further spread in the community,” they wrote. “In an era of multidrug-resistant gonorrhea, ongoing antimicrobial susceptibility surveillance of N. gonorrhoeae is critical to support treatment guidelines, public health intervention and protection.” - by Gerard Gallagher

Disclosure: The authors report no relevant financial disclosures.

    Perspective

    Photo of Carlos del Rio

    This case report from Canada of a clinical isolate of Neisseria gonorrhoeae that is resistant to third-generation cephalosporins is certainly concerning. The epidemiologic and genomic data suggest that this isolate was introduced from Asia, with a similar isolate having been reported from Japan in 2015. It is fortunate that in this case a culture was obtained, which allowed antimicrobial susceptibility to be performed. Otherwise, the case would have easily been missed. In this day when most gonorrhea is diagnosed using molecular testing, I suspect that we will be missing similar cases and it will not be until surveillance data are examined from networks like the national Gonococcal Isolate Surveillance Project that other cases will be identified. Given that these resistant strains typically have emerged from Asia, it is expected that they will first be seen in Hawaii and the West Coast of the continental U.S. Once we lose ceftriaxone for the treatment of gonorrhea, there are very few options left. Thus, there is an urgent need to develop new therapies as well as novel approaches to detect antimicrobial resistance in the absence of culture. N. gonorrhoeae has been included among the organisms of concern in the National Strategic Plan for Combating Antimicrobial Resistance.   

    Carlos del Rio, MD

    Professor of medicine
    Emory University School of Medicine

    Disclosure: Del Rio reports no relevant financial disclosures.