Extragenital screening for men who have sex with men (MSM) has improved the detection, diagnosis, and treatment of pharyngeal and rectal chlamydia and gonorrhea infections. Early studies suggested that nucleic acid amplification testing (NAAT) of extragenital sites among MSM was productive and that more than 50% of Neisseria gonorrhoeae and Chlamydia trachomatis infections among MSM would be missed if extragenital testing were not done.1–3 In response, the Philadelphia Department of Public Health (PDPH) Public Health Lab was one of many laboratories that performed internal validation of NAATs to begin screening at extragenital sites.
In a July 2009 Dear Colleague letter (dated July 13, 2009), local health departments were encouraged to partner with gay-focused Community Based Organizations (CBOs) to support comprehensive sexually transmitted disease (STD) screening at all exposure sites to detect infections that might not otherwise be diagnosed. Soon after that, the PDPH STD Control Program partnered with several gay-focused CBOs that ran non–clinic-based screening and education sites. Testing at extragenital sites was already being collected in the categorical STD clinics including the City's Health Center #1 STD Clinic and being performed in the PDPH Public Health Lab.
A highly productive collaboration with the Mazzoni Center's Washington West Project (WWP) has provided numerous opportunities for extragenital screening. Washington West Project was established in 1996 to make HIV testing and other services more accessible to LGBT communities. Washington West Project is a storefront property in a section of the city commonly referred to as the “Gayborhood.” This area has a high concentration of gay bars, clubs, and other gay-owned businesses. It is also an area with a high concentration of male and transgender sex workers. Rapid HIV testing services are provided at WWP during both traditional and nontraditional hours (open until 9 PM on weeknights and open afternoons during the weekend). Washington West Project has phlebotomists who draw blood for HIV and syphilis testing; however, all chlamydia and gonorrhea testings (urogenital, pharyngeal, and rectal) are self-collected by patients. Health Center #1, although serving more men than women, is more of a traditional clinical setting. In addition, the clinic is only open during weekdays from 8:30 AM to 4:00 PM with extended hours on Mondays and Wednesday until 7 PM. Finally, because Health Center #1 has medical staff, all extragenital specimens are clinician collected.
To date, although there is a commercially available NAAT for urogenital testing, there is no commercially available test that has been Food and Drug Administration (FDA) approved for extragenital testing of N. gonorrhoeae and C. trachomatis. However, many commercial and other laboratories have done internal validation to use available NAAT testing approved for the detection of genital infection for extragenital testing. In late 2014, the FDA released a Draft Framework for Oversight of Laboratory Developed Tests, which, if adopted, could eliminate the current internal validation of extragenital specimens and require laboratories to suspend testing while laboratories conduct a costly and time-consuming premarket review for validation before they could resume testing.4 The primary purpose of this analysis was to document the potential missed infections should extragenital testing no longer be available. In addition, limited evidence exists showing the efficacy of disease finding in extragenital testing when the specimen was self-collected in nonclinical settings versus clinician-collected specimens in health care settings.5
Data from Health Center #1 STD Clinic and WWP for visits between July 1, 2014 and June 30, 2015 were extracted from their respective data systems. Data for this analysis were limited to include only MSM as they represent the group where extragenital screening would be more beneficial than urogenital screening alone. Men who have sex with men were defined as men who self-reported having sex with either men or both men and women in the past 12 months. Inclusion further required that a urine test must have been ordered as well as either a rectal or pharyngeal swab or both. Data were tabulated to assess the number of missed infections if only urogenital testing was available, which required a negative urine test result to definitely say that the extragenital infection would have been “missed.” Patients with a positive urogenital test result were not further stratified to evaluate additional sites of infection as they would have been adequately treated based on the results of the urine test.
Between July 1, 2014 and June 30, 2015, 1945 MSM tested at WWP, whereas 1391 MSM were tested at Health Center #1. A total of 214 (11%) and 366 (26%) were excluded from the perspective testing locations due to no urogenital testing being resulted. For WWP, if extragenital testing was eliminated, 80.7% of patients with gonorrhea would have been missed compared with 83.3% of patients with gonorrhea missed at Health Center #1. In both sites, the most missed diagnosis if extragenital testing was eliminated would have been pharyngeal diagnoses of gonorrhea. For chlamydia, both sites also had a high percentage of potentially missed infections had extragenital testing not been available: 72.4% at WWP and 73.0% at Health Center #1. Unlike, gonorrhea, most missed chlamydia diagnoses should extragenital testing be eliminated would have been rectal infections (Table 1).
Findings in Philadelphia support other previous studies that show extragenital testing among MSM to be key in identifying, treating, and halting the spread of STDs.1,6–8 Most extragenital infections tend to be asymptomatic, and more than 70% of infected MSM would not have been identified without the current screening programs.8 Although this percentage of potentially missed infections is higher than noted in other studies,1,8 the authors speculate that this increase is due to more routine extragenital screening of asymptomatic MSM based on their reported risk behavior. In addition, rectal infections have been associated with a higher rate of subsequent HIV infection among MSM, and NAAT-based testing has allowed for identification of MSM with rectal infection.9
To date, Philadelphia and other programs have created partnerships with CBOs that serve LGBT community to address the at-risk population of MSM. The above results demonstrate that with currently validated extragenital NAAT testing, these screening activities are successful. If eliminated, without appropriate replacement with FDA-approved testing, this would have a negative impact on current screening program and partnerships. This would negatively impact case finding among MSM, a population that has been disproportionately affected by sexually transmitted infections. At this time, early identification and follow-up of gonorrhea infections at both rectal and pharyngeal sites may retard the development of resistance in this population.10 In addition, as we and many other sites have increasing access to preexposure prophylaxis for HIV, the early detection of rectal infection, both gonorrhea and chlamydia, is important in identification of most at-risk patients.
1. Kent CK, Chaw JK, Wong W, et al. Prevalence of rectal, urethral, and pharyngeal chlamydia and gonorrhea detected in 2 clinical settings among men who have sex with men: San Francisco, California, 2003. Clin Infect Dis 2005; 41: 67–74.
2. Katz K, Klausner J, Bernstein K, et al. Clinic-based testing for rectal and pharyngeal Neisseria gonorrhoeae
and Chlamydia trachomatis
infections by community-based organizations—Five cities, United States, 2007. MMWR 2009; 58: 716–719.
3. Schachter J, Moncada J, Liska S, et al. Nucleic acid amplification tests in the diagnosis of chlamydial and gonococcal infections of the oropharynx and rectum in men who have sex with men. Sex Transm Dis 2008; 35: 637–642.
4. FDA. Draft Guidance for Industry, Food and Drug Administration Staff, and Clinical Laboratories Framework for Regulatory Oversight of Laboratory Developed Tests (LDTs). 2014. Available at: http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM416685.pdf
5. Currie MJ, Martin SJ, Soo TM, et al. Screening for chlamydia and gonorrhoea in men who have sex with men in clinical and non-clinical settings. Sex Health 2006; 3: 123–126.
6. Barbee LA, Dombrowski JC, Kerani R, et al. Effect of nucleic acid amplification testing on detection of extragenital gonorrhea and chlamydial infections in men who have sex with men sexually transmitted disease clinic patients. Sex Transm Dis 2014; 41: 168–172.
7. Gunn RA, O'Brien CJ, Lee MA, et al. Gonorrhea screening among men who have sex with men: Value of multiple anatomic site testing, San Diego, California, 1997–2003. Sex Transm Dis 2008; 35: 845–848.
8. Patton ME, Kidd S, Llata E, et al. Extragenital gonorrhea and chlamydia testing and infection among men who have sex with men—STD Surveillance Network, United States, 2010–2012. Clin Infect Dis 2014; 58: 1564–1570.
9. Pathela P, Braunstein SL, Blank S, et al. HIV incidence among men with and those without sexually transmitted rectal infections: Estimates from matching against an HIV case registry. Clin Infect Dis 2013; 57: 1203–1209.
10. Barry PM, Klausner JD. The use of cephalosporins for gonorrhea: The impending problem of resistance. Expert Opin Pharmacother 2009; 10: 555–577.