Private physicians in the United States were questioned regarding treatment of venereal disease in a three-month period of 1968. Of those queried, 134,633 physicians (65.3%) responded—43,720 (32.5% of responding physicians) indicated treatment of syphilis or gonorrhea in the period; 4,370 (3.2% of responding physicians) indicated treatment of 8,849 cases of infectious syphilis; 10,934 physicians had treated 22,022 cases of "other syphilis"; and 39,392 had treated 185,548 cases of gonorrhea. Comparison of survey indications of cases treated with cases reported in the period showed only 12% (18.7%) of infectious syphilis cases and 10.9% (16.9%) of gonorrhea cases had been reported if estimates for nonresponding physicians are included (or excluded). Syphilis and gonorrhea remain vastly underreported although the reporting of syphilis and gonorrhea has slightly improved since 1962.
Fleming WL, Brown WJ, Donohue JF, Branigin PW. National Survey of Venereal Disease Treated by Physicians in 1968. JAMA. 1970;211(11):1827-1830. doi:10.1001/jama.1970.03170110033006