Tonsillectomy and infectious mononucleosis.

Tonsillar tissue may be the primary site of infection with Epstein-Barr virus (EBV), the etiologic agent of classical infectious mononucleosis (IM). Therefore, a retrospective study of the association between tonsillectomy and IM was performed in a college student population. In the first part of the study, tonsillectomy rates were compared between 164 IM-positive students and 164 student controls who attended UCLA in 1972-1975. Although it was determined that the development of IM during college years was statistically less commin in tonsillectomized students, the difference was not inordinately large and probably had no significant biologic meaning. The authors speculate that the difference was due to the greater likelihood, and greater yield, in considering the diagnosis of IM in young adults with enlarged, inflamed tonsils. In support of this is the fact that IM-positive students who had received a prior tonsillectomy usually had the surgical procedure performed at a younger age than the control group. Conceivably, tonsillar ablation in the very young is more liable to result in incomplete removal and eventual regrowth of this tissue. Indeed, six IM-positive students who had received a tonsillectomy at six years of age or less were found to have exudate in tonsillar fossae or pillars during their IM episode. In the second part of the study, clinical and laboratory measures were found to be similar between a larger group of IM-positive students with or without a history of prior tonsillectomy.