The continuous decrease in the number of SSPE annual cases ten years after compulsory anti-measles immunization.

The record of SSPE cases diagnosed immunochemically and serologically in our laboratory, standing for about 60% of the total new cases reported in our country, shows a significant decrease in the incidence in 1988-89 (from 5.21 new cases per year per million total population in 1987 to 1.82 cases in 1988). In 85% of the patients, SSPE onset occurred at the age of 10 years or more, suggesting the possibility of a primary measles infection before anti-measles immunization became compulsory. High serum and CSF anti-measles antibody titres in recently diagnosed patients show subclinical long-term courses. Further serologic tests for viruses inducing persistent infections (herpes viruses, AgHBs and HIV) do not show any difference when compared to a control group excepting an increased incidence of anti-cytomegalic titres.