Screening for syphilis in persons at risk for infection provides substantial benefit

The U.S. Preventive Services Task Force (USPSTF) has found convincing evidence that screening for syphilis infection in asymptomatic, nonpregnant persons at increased risk for infection provides substantial benefit. The report appears in the June 7 issue of JAMA.

This is an A recommendation, indicating that the USPSTF recommends the screening and that there is high certainty that the net benefit is substantial.

The number of cases of primary and secondary syphilis have been increasing since 2000. In 2014, approximately 20,000 cases of syphilis were reported in the United States. Left untreated, syphilis can progress to late-stage disease in about 15 percent of persons who are infected. Late-stage syphilis can lead to development of inflammatory lesions throughout the body, which can lead to cardiovascular or organ dysfunction. Syphilis infection also increases the risk for acquiring or transmitting human immunodeficiency virus (HIV) infection. To update its 2004 recommendation on screening for syphilis infection in nonpregnant adults, the USPSTF reviewed the evidence on screening for syphilis infection in asymptomatic, nonpregnant adults and adolescents, including patients coinfected with other sexually transmitted infections (such as HIV). Screening for syphilis in pregnant women was updated in a separate recommendation statement in 2009 (A recommendation).

The USPSTF is an independent, volunteer panel of experts that makes recommendations about the effectiveness of specific preventive care services such as screenings, counseling services, and preventive medications.

Risk Assessment
Men who have sex with men and persons living with HIV have the highest risk for syphilis infection. Other factors that are also associated with increased prevalence rates include a history of incarceration or commercial sex work, geography, race/ethnicity, and being a male younger than 29 years.

Detection
There are numerous screening tests for syphilis. Most common is a combination of nontreponemal and treponemal antibody tests. The USPSTF found convincing evidence that screening algorithms with high sensitivity and specificity are available to accurately detect syphilis.

Benefits of Early Detection and Treatment
The USPSTF found convincing evidence that treatment with antibiotics can lead to substantial health benefits in nonpregnant persons who are at increased risk for syphilis infection by curing syphilis infection, preventing manifestations of late-stage disease, and preventing sexual transmission to others.

Harms of Early Detection and Treatment
The USPSTF found no direct evidence on the harms of screening for syphilis in nonpregnant persons who are at increased risk for infection. Potential harms of screening include false-positive results that require clinical evaluation, unnecessary anxiety to the patient, and the potential stigma of having a sexually transmitted infection. The harms of antibiotic treatment are well established, and the magnitude of these harms is no greater than small.

Findings
The USPSTF concludes with high certainty that the net benefit of screening for syphilis infection in nonpregnant persons who are at increased risk for infection is substantial. Accurate screening tests are available to identify syphilis infection in populations at increased risk. Effective treatment with antibiotics can prevent progression to late-stage disease, with small associated harms, providing an overall substantial health benefit.