Evidence against transmission of Hodgkin's disease in high schools

A survey in Greater Boston identified 1577 new cases of histologically diagnosed Hodgkin's disease between 1959 and 1973. Of these cases, 448 were of ages such that the patients might have attended high school during 1960-73. For 96 per cent of these persons high-school attendance was ascertained. First of all, we studied Hodgkin's disease at high schools in two time periods. The 13 high schools with cases present in 1960-64 were matched with 26 schools that had no cases in this period, and we compared these two groups for the occurrence of Hodgkin's disease during 1965-69. The proportion of "exposed" high schools that had cases diagnosed in the second period was 0.62, and that for the matched high schools was 0.65. We performed this two-time-period analysis for 25 additional combinations of time periods; in none of them did we find a statistically significant positive result. Secondly, we studied the risk of Hodgkin's disease among persons who had attended high school at the same time as a diagnosed case. We followed these "exposed" persons through 1973 and observed 12 cases among them, whereas the expected number of cases was 13.9. Thirdly, we evaluated the extent to which members of all possible pairs of cases had attended the same or nearby high schools at the same time. We found no excess of classmate pairs than might have occurred by chance alone. These data suggest that there is no transmission of an etiologic agent for Hodgkin's disease at high schools.