Spontaneous infection or vaccination as cause of acute disseminated encephalomyelitis.

This report describes an approach to determine which of 2 possible etiologies could be responsible for a disease, in this instance acute disseminated encephalomyelitis (ADEM). Information about latency periods was obtained from eighteen reference sources in the literature. Analysis of these data indicate that it would be 9-18 times more likely for ADEM to develop 5 days after a wild virus infection (measles, for example) than 28 days after a vaccination.