Mycoplasma pneumoniae Pneumonia in an Urban Area

Abstract

Incidence of Mycoplasma pneumoniae pneumonia was studied in a large medical cooperative in Seattle from 1963 through 1968. Twenty percent of all pneumonia was associated with M pneumoniae infection. The disease was endemic and without seasonal fluctuation during the last and the first two years of study. An epidemic started late in 1965 and peaked in January 1967. Children 5 to 9 years old consistently had the highest attack rate, while the proportion of all pneumonia due to M pneumoniae was highest among teenagers. Patients with M pneumoniae had higher rates of headache, fever, sore throat, skin rash, and ear complications, but lower rates of coryza and leukocytosis than patients with pneumonia of other etiologies. Duration of illness increased with age. Treatment with tetracyclines and erythromycin reduced the length of illness, but not the antibody response. Follow-up examinations revealed no serious sequelae.