Screening | Questions & Answers | 2015 STD Treatment Guidelines

Question: Who should be screened for oral/rectal infections and when?

At this point in time, the data are strongest for screening men who have sex with men (MSM) for gonorrhea and chlamydia at extragenital sites when they report exposure.  The oral and rectal sites are more likely to be infected with gonorrhea and chlamydia than the urogenital site, especially among asymptomatic MSM.  Specifically, the CDC recommends screening sexually-active MSM (HIV+ and HIV-) for oral gonorrhea and for rectal gonorrhea and chlamydia at least annually, and more frequently (every three to six months) if risk behaviors persist, or if they or their sexual partners have multiple partners. Testing for gonorrhea and chlamydia at oral and rectal sites is less clear for women, and for men who have sex only with women, but can be considered in any individual reporting exposure.

The prevalence of oral chlamydia is low, even among individuals with chlamydia at other sites (i.e., genital, rectal) and, therefore, it is not recommended to routinely screen for chlamydia at the oral site, but only to test for gonorrhea at this site.  However, if chlamydia is detected at the oral site (many of the NAAT tests test for both simultaneously), the infection should be treated.  

Obtaining an accurate sexual history can be challenging in any population, and provider comfort is essential to ensure an accurate assessment.  It is possible that patients may not be completely forthcoming about exposure at some of these sites, and that infections may be missed if the patient is screened based on their history (versus screened at all sites regardless of history).  However, at this time it is recommended that clinicians use the patient history to guide site-specific screening.

Question: What is the recommendation for anal Pap smears in men who have sex with men (MSM) and women who engage in anal sex?

Currently, there are insufficient data regarding the natural history of HPV infection, and the evolution of anal dysplasia, as well as data regarding the efficacy of anal Pap smears and subsequent interventions for the prevention of anal cancer. This data would be needed to provide recommendations for the use of anal Pap screening in individuals (MSM and women) who have engaged in anal sex.  The prevalence of abnormal Pap smears is high in these populations (particularly in individuals who are HIV+), as is the finding of histologically-confirmed, high-grade disease.  However, it is not known whether treating the high-grade disease prevents anal cancer.  In the meantime, some experts perform anal Pap testing and high-resolution anoscopy (HRA) on their patients as part of regular clinical care.  If an anal Pap program is embarked upon, it is important to set up a system of follow-up for abnormal anal Pap tests (i.e., define referral patterns) prior to initiation of the program, as the frequency of abnormal Pap tests (particularly among HIV+ MSM) is high.