Background: The clinical symptoms and durations of illness of patients with infectious mononucleosis (IM) are variable and are poorly documented in the scientific literature.
Methods: Patients who presented for care at the Student Health Service of a Canadian university between September 1985 and May 1988 and had been diagnosed as having IM were surveyed. Health experience during the acute and convalescent phases of IM was compared with that of a group of patients matched for age, sex, date of diagnosis, and year of study, who had suffered acute upper respiratory tract infections (URI), other than Epstein-Barr virus (EBV)-induced, during the same period.
Results: Students were sicker for longer after IM than after non-EBV-induced URI. During the acute phase of illness, the symptoms of fatigue (P = less than .000001), night sweats (P = .000001), and painful neck swelling (P = .00003) were seen significantly more often in the IM group. The severity and duration of these symptoms were also significantly worse in IM patients. Getting tired easily (P = .002), diurnal somnolence (P = .002), and depression (P = .002) were significantly more common postacute symptoms. Eleven percent of IM patients reported persistence of symptoms longer than 100 days, and in 6% of patients the symptoms had persisted after 1 year. Convalescent cases showed a trend toward reduced alcohol intake and, perhaps, reduced alcohol tolerance.
Conclusions: IM involves excessive morbidity in a student community compared with URI that was other than EBV-induced, during both the acute and the postacute phases of infection.