Capitol Hill briefing sheds light on imminent emergence of drug-resistant gonorrhea
Testament to “too many years of neglect of investments in sexually transmitted diseases (STDs),” a gonorrhea superbug is expected to make its appearance in the U.S. within the near future. That’s according to a panel of experts that spoke at a Capitol Hill briefing Friday hosted by Rep. Barbara Lee’s (D-CA) office along with the National Coalition of STD Directors.
Caused by the bacterium Neisseria gonorrhoeae, gonnorhea can lead to pelvic infelmmatory disease and can result in adverse reproductive health complications such as infertility. The vast majority of cases are asymptomatic or have non-specific symptoms, making it difficult to detect. Although at an all-time low in the U.S. (300,000 cases reported in 2011), gonorrhea prevalence is the highest and is increasing the most in the southeastern U.S., the same placee where HIV rates are rising, said presenter Gail Bolan, director of the Division of STD Prevention in the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention at the Centers for Disease Control and Prevention (CDC). She added that gonorrhea is at least 10 times more prevalent among blacks than whites in the U.S.
Bolan published an article on the subject in The New England Journal of Medicine in February outlining the problem – “During the past three years, the wily gonococcus has become less susceptible to our last line of antimicrobial defense, threatening our ability to cure gonorrhea and prevent severe sequelae,” or conditions resulting from the disease. Antibiotic resistance undermines treatment success, heightens risk of complications and facilitates passage of infection to uninfected individuals, Bolan said. And gonorrhea has demonstrated the ability to progressively develop antibiotic resistance over time.
The 2010 CDC STD treatment guidelines recommend treating uncomplicated gonococcal infections of the cervix, urethra and rectum with one injected dose of Ceftriaxone (a cephalosporin) or if not an option one oral dose of Cefixime, plus one dose of azithromycin orally or doxycycline twice daily for seven days.
“The challenge now is we have no other drugs to go to if we have cephalosporin resistance,” Bolan said, adding that the pattern of growing resistance is fairly similar to what they saw for floroquinolones. First cases arise in the men who have sex with men population, then it spreads to the heterosexual population. “Our drugs are showing they are not as effective as they used to be – we have had to use a higher level of drug to kill the organism at concerning rates over the past few years.”
Cases of drug-resistant disease have already been reported in Europe, Japan and other parts of Asia. “We anticipate it’s coming [to the United States] in the next couple of years,” Bolan said. There is a lack of timely and sensitive antibiotic resistant gonorrhea surveillance systems globally. And in areas where there are few to no gonorrhea surveillance systems in place, such as sub-Saharan Africa, the size of the threat of drug resistant strains are anyone’s guess.
Even though they have quite a robust HIV treatment capacity, “unfortunately in Africa they have really such limited STD infrastructure,” Bolan said, and with limited capacity to do diagnostics, gonorrhea patients are treated based on their symptoms. “We are working with WHO to determine the role it might be playing in the HIV epidemic, and we hope to have sentinel systematic way to assess what’s going on globally.”
Gonorrhea presents a particular challenge in controlling the spread of HIV/AIDS. According to the CDC, individuals who are infected with STDs are at least two to five times more likely than uninfected individuals to acquire HIV infection if they are exposed to the virus through sexual contact. In addition, if an HIV-infected individual is also infected with another STD, that person is more likely to transmit HIV through sexual contact than other HIV-infected persons. According to some studies, the concentration of HIV in semen is as much as 10 times higher in men infected with both gonorrhea and HIV than men infected only with HIV.
The panelists urged incentivization to encourage development of new, potent antimicrobials to combat gonorrhea, to include pushing for a CDC-National Institutes of Health treatment trial studying existing drugs like gendomicine for their potential efficacy. Without incentives or a public-private partnership model, entry into the market to develop and study new treatment candidates is weak. A recent model indicated that at discovery an antibiotic is worth minus $50 million to a company, when by comparison musculoskeletal drugs have an estimated value of $1 billion at discovery.
The panelists also highlighted the low awareness of problem and declining STD control resources nationwide (total CDC STD prevention spending in 2011 was $154.7 million), which means a low likelihood of preventing and/or controlling resistance. “We want to make sure that doctors know about the optimal care of persons diagnosed with gonorrhea,” for example that as of 2007 they shouldn’t be treating with floroquinolones, doing more work to prevent re-infection by offering condoms and prevention counseling, and reporting drug-resistance immediately.
“We need to get the disease burden down even lower so that when these untreatable cases do emerge it will be easier to manage,” Bolan said.
The CDC is working closely on the issue with the World Health Organization (WHO), who plan to launch a global action plan on May 2. The CDC is also in the process of updating their 2010 gonorrhea treatment recommendations, which they hope to have up with a treatment plan by June.