Changing epidemiological features of subacute sclerosing panencephalitis

Background: Subacute sclerosing panencephalitis (SSPE) is a chronic central nervous (CNS) system infection caused by measles virus. Because changing i mmunization practices affect the epidemiology of measles and consequently S SPE, we examined the epidemiological data of our SSPE registry. Materials and Methods: Age of onset, age at onset of measles, duration of L atent period and immunization status were examined in cases recorded at the SSPE Registry Center in Turkey between 1975 and 1999. Results: Age of onset diminished from 13 years before 1994 to 7.6 years aft er 1995; age at onset of measles declined from 29 months to 20 months and t he Latent interval from 9.9 years to 5.9 years. Age at onset of measles and immunization status did not directly affect the duration of the Latent per iod. Conclusion: Although its incidence has decreased in Turkey, SSPE has been s een at younger ages in recent years. This change cannot be attributed solel y to younger age at onset of measles. Factors affecting the duration of the Latent period should be investigated further.