During an epidemic of early syphilis, social networks were used for an intervention campaign.
Goal of this Study:
To characterize the epidemic and describe the yield of new cases from index-case interviews.
Analyses of morbidity data collected by the Montgomery County, Alabama, sexually transmitted disease program determined the course of the epidemic and characterized the new case yields from social networks identified via index-case interviews (partner notification investigations) and interviews with sex partners and their associates (cluster investigations). Results and costs were compared to a noncampaign period.
The number of reported syphilis cases nearly doubled from 1990 to 1991 (201 to 348 per 100,000 residents). During the 21-week campaign, 373 case-patients had partner notification/cluster investigations; 113 (11%) of 984 sex partners and 41 (3%) of 1,146 high-risk associates (persons identified during cluster investigations) had syphilis. No subgroup of case-patients for which the partner notification/cluster investigation yielded more infected persons than other subgroups was identified. The cost per case detected was more than twice that during a non-campaign period ($1,627 vs. $771).
Partner notification investigations yielded more infected persons than cluster investigations. Further evaluation is needed to determine the role of intense partner notification/cluster investigators' efforts in the control of epidemic syphilis.