Screening for Syphilis: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Abstract

Importance: Screening for syphilis infection is currently recommended for high-risk individuals, including those with previous syphilis infection, an infected sexual partner, HIV infection, or more than 4 sex partners in the preceding year.

Objective: To update a 2004 systematic review of studies of syphilis screening effectiveness, test accuracy, and screening harms in nonpregnant adults and adolescents.

Data sources: Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews through October 2015 and Ovid MEDLINE (January 2004 to October 2015), with updated search through March 2016.

Study selection: English-language trials and observational studies of screening effectiveness, test accuracy, and screening harms in nonpregnant adults and adolescents.

Data extraction and synthesis: One investigator abstracted data, a second checked data for accuracy, and 2 investigators independently assessed study quality using predefined criteria.

Main outcomes and measures: Transmission of disease, including HIV; complications of syphilis; diagnostic accuracy; and harms of screening.

Results: No evidence was identified regarding the effectiveness of screening on clinical outcomes or the effectiveness of risk assessment instruments; the harms of screening; or the effectiveness of screening in average-risk, nonpregnant adolescents or adults or high-risk individuals other than men who have sex with men (MSM) or men who are HIV positive. Four non-US studies indicated higher rates of syphilis detection with screening every 3 months vs 6 or 12 months for early syphilis in HIV-positive men or MSM. For example, there was an increased proportion of asymptomatic, higher-risk MSM in Australia (n = 6789 consultations) receiving a diagnosis of early syphilis when tested every 3 months vs annually (53% vs 16%, P = .001), but no difference among low-risk MSM. Treponemal and nontreponemal tests were accurate in asymptomatic individuals (sensitivity >85%, specificity >91%) in 3 studies but required confirmatory testing. Reverse sequence testing with an initial automated treponemal test yielded more false reactive test results than with rapid plasma reagin in 2 studies, one with a low-prevalence US population (0.6% vs 0.0%, P = .03) and another in a higher-prevalence Canadian population (0.26% vs 0.13%).

Conclusions and relevance: Screening HIV-positive men or MSM for syphilis every 3 months is associated with improved syphilis detection. Treponemal or nontreponemal tests are accurate screening tests but require confirmation. Research is needed on the effect of screening on clinical outcomes; effective screening strategies, including reverse sequence screening, in various patient populations; and harms of screening.