Diverging gonorrhea and syphilis trends in the 1980s: Are they real?

Background. The purpose of this study was to evaluate whether the divergence in national trends of gonorrhea and syphilis from 1986 to 1989 in the United States was real and if overall trends masked a contemporaneous increase in both diseases in a core group. Methods. We analyzed the following: (1) reported cases of gonorrhea and primary and secondary syphilis in the United States for the years 1981 to 1989, (2) gonorrhea screening results from six states for the years 1985 to 1989, and (3) reported cases of gonorrhea and primary and secondary syphilis by census tract for the years 1986 to 1989 in one city. Results. The incidence of gonorrhea decreased 22% in the United States from 1986 to 1989 while the incidence of primary and secondary syphilis increased 59%. Among Blacks, syphilis incidence increased 100% and gonorrhea incidence decreased 13%; among Whites and Hispanics, the incidence of both diseases decreased. Results from gonorrhea screening among females in six states agree with gonorrhea incidence trends in those areas. Race-specific and census tract analyses of data from a number of metropolitan areas where overall rates diverged did not demonstrate a group in which the incidence of both diseases increased. Conclusions. We conclude that diverging trends of gonorrhea and syphilis from 1986 to 1989 are real and emphasize differences in the epidemiologic characteristics of these two sexually transmitted diseases.