Identifying likely syphilis transmitters: implications for control and evaluation.

BACKGROUND/OBJECTIVES: Persistence of syphilis in communities may be maintained by relatively small groups of high-risk persons centrally placed among a larger group with low to moderately risky behavior. We sought to determine which control strategies identified particularly high-risk, early-stage syphilis cases considered to have high prevention value.

METHODS

In 2 cities with recent heterosexual outbreaks, data were abstracted for early syphilis cases from 1997 through 2002. Disease stage and number of sex partners were used to create an index to estimate the relative likelihood and magnitude of future transmission had the case not been treated. We estimated the relative transmission potential for each stage of syphilis (primary = 4.3, secondary = 2.5, and early-latent = 1.0) and multiplied by the number of reported partners to determine a prevention value score. Cases scoring >10 were considered high prevention value. Cases were stratified by the method used to detect the case.

RESULTS

Of 1,700 female early syphilis cases, 174 (10%) were high value. Cases were identified by private physicians (28% of all female cases and 16% of high-value cases), jails (19% of all, 40% of high-value cases), partner notification (16% of all, 10% of high-value cases), sexually transmitted disease (STD) clinic (9% of all, 13% of high-value cases), and the emergency room (8% of all, 4% of high-value cases). Of 1,851 male cases, 228 (12%) were high value. Cases were identified by jails (27% of all male cases and 14% of high-value cases), STD clinic (21% of all, 47% of high-value), private physicians (17% of all, 17% of high-value), partner notification (14% of all, 11% of high-value), and the emergency room (6% of all, 14% of high-value).

CONCLUSIONS

Private physicians identified the most female cases; however, jail screening identified the most high-prevention-value female cases. Jail screening identified the most male cases; however, the STD clinic (self-referred) identified the most high-prevention-value cases. Partner notification identified relatively few high-value cases.