STD Quarterly

New syphilis guidelines will change your practice

Put syphilis testing on your radar screen: Updated guidelines from the U.S. Preventive Services Task Force (USPSTF) recommend that health care providers perform syphilis screening on pregnant women and people who are at high risk for syphilis infection.1

The task force reviewed evidence from 1994 to 2003 to bring its original 1996 recommendations up to date. What prompted the task force to take another look at the subject? Two factors: a rise in syphilis rates and updated evidence indicating that screening of pregnant women can decrease the prevalence of congenital syphilis in newborns,2 says Ned Calonge, MD, MPH, USPSTF chairman and chief medical officer for the Denver-based Colorado Department of Public Health and Environment.

Rates are climbing

Syphilis rates in the United States rose in 2002 for the second consecutive year, following a decade-long decline that resulted in an all-time low in 2000, according to the Atlanta-based Centers for Disease Control and Prevention (CDC).3 The increase was due in large part to increases in reported syphilis cases among men, particularly gay and bisexual men.3

Identifying and treating syphilis during prenatal visits is important. Congenital syphilis infection results in fetal or perinatal death in 40% of affected pregnancies.4 In surviving newborns, it can result in disease complications such as central nervous system abnormalities; deafness; multiple skin, bone, and joint deformities; and hematological disorders.4

"We want to make sure that while syphilis rates in the general population are really quite low, syphilis is still around, and screening these high-risk populations can find the disease early, treat it, and keep it from becoming more of a problem," says Calonge.

Who’s at risk?

According to the USPSTF, the people who fall into a high-risk category for syphilis includes men who have sex with men and engage in high-risk sexual behavior, commercial sex workers, persons who exchange sex for drugs, and those in adult correctional facilities. Optimal screening frequency has not been determined for these high-risk populations; clinicians should consider the characteristics of the communities they serve in determining appropriate screening strategies, state the new recommendations.1

All pregnant women should be tested at their first prenatal visit. For women in high-risk groups, repeat serologic testing may be necessary in the third trimester and at delivery. Screening tests include the Venereal Disease Research Laboratory (VDRL) or rapid plasma reagin (RPR). The fluorescent treponemal antibody absorbed (FTA-ABS) or Treponema pallidum particle agglutination (TP-PA) are used as confirmatory tests. Penicillin C has been an effective treatment for syphilis infection. Researchers are looking at the effectiveness of other antibiotics, such as azithromycin.5

Where does the USPSTF stand on routine screening in the general population? According to the new guidance, the task force recommends against routine screening of people who are not at increased risk for syphilis infection and do not show symptoms of the disease.

"Given the low incidence of syphilis infection in the general population and the consequent low yield of such screening, the USPSTF concludes that potential harms of screening (i.e., opportunity cost, false-positive tests, and labeling) in a low-incident population outweigh the benefits," the recommendation states.1

Risk is real 

Between 2001 and 2002, the overall rate of syphilis increased 9.1%, from 2.2 cases to 2.4 cases per 100,000 population, the highest rate since 1999, according to CDC statistics.1 The total number of reported cases increased 12.4%, from 6,103 to 6,862 cases. Since some syphilis cases go undiagnosed, the actual number of infections may likely be higher, say public health officials.

The job of eliminating syphilis in the United States is not done, according to Ronald Valdiserri, MD, MPH, deputy director of the CDC National Center for HIV, STD, and TB Prevention. Despite historic lows in some populations, increases among gay and bisexual men represent a major new challenge to STD and HIV prevention efforts, he notes. The CDC is working with state and local community partners to reverse the trend.

References

1. U.S. Preventive Services Task Force. Screening for syphilis infection: recommendation statement. Ann Fam Med 2004; 2:362-365.

2. Coles FB, Muse AG, Hipp SS. Impact of a mandatory syphilis delivery test on reported cases of congenital syphilis in Upstate New York. J Pub Health Manag Pract 1998; 4:50-56.

3. Centers for Disease Control and Prevention. Primary and secondary syphilis — United States, 2002. MMWR 2003; 52:1,117-1,120.

4. Walker DG, Walker GJ. Forgotten but not gone: The continuing scourge of congenital syphilis. Lancet Infect Dis 2002; 2:432-436.

5. Hook EW III, Martin DH, Stephens J, et al. A randomized, comparative pilot study of azithromycin versus benzathine penicillin G for treatment of early syphilis. Sex Transm Dis 2002; 29:486-490.