In this issue of the journal, Garrett and colleagues1 present data from a survey that describes both testing methods for Neisseria gonorrhoeae and, within those laboratories performing culture, the prevalence of antimicrobial susceptibility testing of gonococcal culture isolates in the Washington, DC, area between 2007 and 2012. The article provides valuable data that, in turn, have important implications for the role of laboratories in both individual and programmatic efforts to manage and control gonorrhea.
The data presented provide an interesting snapshot of the state of testing for N. gonorrhoeae in the Washington, DC, area between 2007 and 2012 at a time when methods for gonorrhea detection were likely to have been evolving. In their survey, the authors collected data from 19 (61%) of 32 laboratories in their area, a sample that accounted for more than 90% of reported gonorrhea tests in the region.1 Perhaps reflecting changing practices for gonorrhea detection, testing by culture and nucleic acid amplification testing (NAATs) were both relatively common during the survey period. Of the responding laboratories, most (14 of 19%–89%) performed gonorrhea culture, whereas a slightly lower proportion (15 of 19%–79%) were using NAATs. It is also noteworthy that 60% of the 10 laboratories that reported NAAT testing for gonorrhea detection had validated these tests for use with pharyngeal or anorectal specimens. It is heartening to see both that more than half of laboratories sustained the ability to culture gonorrhea in the NAATs era as well as the availability of NAATs testing for gonorrhea at extragenital sites in more than half of laboratories. I would hope that both maintenance of culture and expansion of the ability to test extragenital specimens using NAATs technology have continued in the 3 years since the data collection for this study concluded.
The major focus of this article, however, relates to testing of N. gonorrhoeae isolates collected from local patients to evaluate susceptibility to the antibiotics used for treatment. The authors raise concerns that only approximately one-third (6/17) of local laboratories that performed culture also performed antibiotic susceptibility testing of gonococcal isolates. This was most often performed at the request of clinicians and thus was not a systematic practice which generated results that clearly reflected local patterns of antimicrobial susceptibility. When such testing was performed, it was most often performed away from the primary laboratories as a “send-out” test, with respondents citing factors such as lack of demand, time required for testing, and the specialized nature of the testing as reasons for not routinely offering this test in their own laboratories. As noted by the authors, agar dilution minimal inhibitory concentration testing to determine gonococcal antimicrobial susceptibility is a somewhat specialized procedure that requires several additional days beyond completion of initial culture to provide a result. Thus, unlike antimicrobial susceptibility testing routinely performed in hospital laboratories to guide treatment decisions in patients with other active infections, using present technology gonococcal antimicrobial will continue to be an “after the fact” observation with little or no direct impact on individual patient care.
In the discussion of their findings, the authors go on to propose that “enhanced surveillance is needed to monitor the prevalence of antibiotic resistant gonorrhea strains circulating among the population.”1 I question this conclusion both in terms of practicality and in terms of need. The United States has had a robust and effective sentinel surveillance system for monitoring national and regional trends in gonococcal antimicrobial susceptibility since 1988.2–7 The Gonococcal Isolate Surveillance Project (GISP) was developed (1) to characterize current antimicrobial susceptibility of N. gonorrhoeae from cities in several geographic regions of the country, (2) to monitor temporal and geographic trends in these susceptibility patterns, (3) to correlate patient characteristics in behaviors with infections caused by resistant gonococci, and (4) to use these data to develop national treatment recommendations for gonorrhea treatment.2 Review of the literature, as well as the last 5 iterations of the Centers for Disease Control and Prevention's sexually transmitted disease treatment guidelines,7,8 testifies to the fact that GISP has succeeded. For nearly 30 years, GISP has provided data that have reliably predicted changes in gonococcal antimicrobial susceptibility and have permitted anticipatory changes to treatment guidelines in a fashion such that public health officials no longer needed to wait for increased numbers of treatment failures to ascertain the need for a change in gonorrhea treatment.
Development of antimicrobial resistance by N. gonorrhoeae seems to be an inexorable process, and GISP has succeeded in effectively monitoring this. Furthermore, in multiple publications, GISP has described important epidemiologic changes3–6 in the populations most effected by gonorrhea and most recently has successfully predicted and guided responses to the development of N. gonorrhoeae with decreased susceptibility to cephalosporin antibiotics.5–7 Likewise the system has detected both outbreaks of resistant gonococcal infections and epidemiologic changes in gonococcal antimicrobial susceptibility in populations most affected by the infection.2,4–7 The Gonococcal Isolate Surveillance Project was designed as sentinel surveillance for gonococcal antimicrobial resistance. The participating clinics were chosen for a variety of factors including that they were likely to reflect sites of importation or emergence of antimicrobial-resistant N. gonorrhoeae (i.e., favoring ports and populous coastal cities), their total gonococcal morbidity, and their willingness and ability to contribute to the process. The coverage by GISP is quite broad, currently involving 28 different collection sites across the nation.8 It is not clear that additional sites are needed or would dramatically improve results. For instance, Garrett et al, describe results from an area within 75 miles of 2 representative GISP collection sites. This is not to say that there are not ways that GISP could be improved. For instance, determination of best practices for transport of specimens for gonorrhea culture to laboratories that continue to perform culture could make participation in GISP easier and permit health care providers across the nation to collect specimens from persons with possible treatment failure after recommend gonorrhea therapy to be systematically evaluated.
Is routine antimicrobial susceptibility testing by laboratories necessary at this time? I think not. The Gonococcal Isolate Surveillance Project continues to accurately detect both national and regional trends in gonococcal antimicrobial susceptibility. At a time when testing for N. gonorrhoeae as well as other sexually transmitted infections is increasingly being performed using NAAT testing, which is more sensitive, more rapidly performed, and more transportable than culture-based methods, to use limited resources to culture and antimicrobial susceptibility testing could possibly have a deleterious effect on gonococcal detection practices. Rather I would suggest that a consideration of the effectiveness of GISP over its nearly 30 years of existence validates it as one of our nation's most valuable and effective surveillance activities which should be continued. Rather than asking local laboratories to invest in time, their limited resources, and expertise in antimicrobial susceptibility testing for N. gonorrhoeae, I believe that it is time for the Centers for Disease Control and Prevention to invest more heavily in support of GISP, not for all laboratories to be testing gonococcal isolates for antimicrobial susceptibility.
1. Garrett TA, Davies-Cole J, Furness B. Laboratory capacity for antimicrobial susceptibility surveillance of Neisseria gonorrhoeae
—District of Columbia, 2007–2012. Sex Transm Dis 2015. Current Issue.
2. Schwarcz SK, Zenilman JM, Schnell D, et al. National surveillance for antimicrobial resistance in Neisseria gonorrhoeae
. The Gonococcal Isolate Surveillance Project. JAMA 1990; 264: 1413–1417.
3. Fox KK, Knapp JS, Holmes KK, et al. Antimicrobial resistance in Neisseria gonorrhoeae
in the United States 1988–1994: The emergence of decreased susceptibility to the fluoroquinolones. J Infect Dis 1997; 175: 1396–1403.
4. Fox KK, del Rio C, Holmes KK, et al. Gonorrhea in the HIV era: A reversal in trends among men who have sex with men. Am J Public Health 2001; 91: 959–964.
5. Goldstein E, Kirkcaldy RD, Reshef D, et al. Factors related to the increasing prevalence of resistance to ciprofloxacin and other antimicrobials in Neisseria gonorrhoeae
, United States. Emerg Infect Dis 2012; 18: 1290–1297 PMC3414012.
6. Kirkcaldy RD, Zaidi A, Hook EW III, et al. Neisseria gonorrhoeae
antimicrobial resistance among men who have sex with men and men who have sex exclusively with women: The Gonococcal Isolate Surveillance Project, 2005–2010. Ann Intern Med 2013; 158: 321–328.
7. Centers for Disease Control and Prevention. Sexually Transmitted Disease Surveillance 2013. Atlanta: U.S. Department of Health and Human Services; 2014.
8. Centers for Disease Control and Prevention. Sexually transmitted disease treatment guidelines. MMWR 2015; 63: 1–137.