School contact among persons with Hodgkin's disease.

The authors evaluated the hypothesis that Hodgkin's disease is transmitted among high school students (in a contagious manner) by determining whether members of a population-based series of young adult cases attended school together more frequently than expected. Cases of Hodgkin's disease were diagnosed from July 1, 1973 through December 31, 1977. Of the 245 cases and 483 matched population controls interviewed, 196 cases and 371 controls attended schools in Massachusetts. School histories of subjects obtained by personal interviews were analyzed to determine the frequency with which subjects had been in the same class or had attended the same school at the same time. In high school, cases were schoolmates more often than expected (relative risk (RR) = 1.2), as well as classmates (RR = 1.9). However, in junior high school, cases were schoolmates less often than expected (RR = 0.8), and none were classmates with four expected. In elementary school, cases were somewhat more likely to be schoolmates (RR = 1.4) with no excess of classmates. The 95% confidence interval for all relative risks includes 1.0.