MESSAGE NOTED: Awareness of AIDS has produced one positive byproduct in Orange County: It's led to a sharp reduction in sexually transmitted diseases, such as gonorrhea and syphilis. Reported cases of venereal diseases have decreased by two-thirds since 1987, health officials say. . . . Says Penny Weismuller of the county's disease control office: "The prevention message we've been giving out on HIV is working for these diseases too."
