Epidemic pneumonia in university students.

Longitudinal surveillance of pneumonia in a university student health service was conducted from 1965-1971 and 1984-1987. Of 104 pneumonia cases documented by chest x-ray, only six were presumed to have bacterial etiology; the remaining 98 were characteristic of atypical pneumonia syndrome. Mycoplasma pneumoniae was the etiology in 51% of the pneumonias in the 1960s and 13% in 1984-1987. Pneumonia incidence was highest in the fall semester in seven of 11 years studied. Annual incidence followed a three- to four-year periodicity. Both of these observations mirror the epidemiology of M. pneumoniae in the world population. Symptoms of cough, headache, malaise, and absence of the physical finding of wheezing were seen more consistently in M. pneumoniae pneumonia than in other atypical pneumonias; other clinical features varied among epidemics. Rapid cold agglutinin tests were positive in 27% of our clinically diagnosed pneumonias and in 36% of those with documented mycoplasmal infections. This study appears to provide a basis for predicting future epidemics of atypical pneumonia in student populations.