The primary aim of this report is to provide a cost effectiveness analysis (CEA) of the proposed protocol in the Detection of Syphilis (EIA+IL). [...] In the non-prenatal population the cost of ii Institute of Health Economics, Cost-effectiveness in the Detection of Syphilis, February 2007 Syphilis_report_2.indd. [...] In the prenatal population the total number of correct diagnoses was 51,510 for the current protocol and 51,517 for EIA+IL; the additional number of correct diagnoses was therefore seven with EIA+IL. [...] In the non-prenatal population the total number of correct diagnoses was 37,876 for the current protocol and 38,035 for EIA+IL; the additional number of correct diagnoses was therefore 159 with EIA+IL. [...] However, the economic impact of reducing syphilis in the testing population will not be affected in the short-run because it is the prevalence of seropositives in the testing population that affects laboratory testing results.