Background: Health departments use reactor grids (sex, age, and serologic test for syphilis [STS] titer criteria) to determine which persons to evaluate for untreated syphilis.
Goal: The goal of the study was to assess reactor grid performance in Chicago and reactor grid use nationally in 1999 to 2000.
Study Design: We reviewed Chicago health department records to identify characteristics of persons with a reactive STS excluded from evaluation by reactor grid criteria and syphilis cases not meeting evaluation criteria. We surveyed health departments regarding reactor grid use.
Results: Of persons with a reactive STS, 46% did not meet criteria for health department evaluation, including 62% of men, 29% of women, and 21% with titers ≥1:8. The reactor grid would have excluded 17% of primary syphilis cases. Overall, 82% of health departments use reactor grids.
Conclusions: Reactor grids are widely used and may exclude persons with infectious syphilis from health department evaluation, especially men. The impact of reactor grid use on syphilis control and surveillance in the United States should be evaluated.