Mycoplasma pneumoniae community-acquired pneumonia: a review of 101 hospitalized adult patients.

The features of community-acquired Mycoplasma pneumoniae pneumonia (MP-CAP) were assessed in a prospective study of 101 adults who were hospitalized over the course of 1 year, and were compared with 245 patients who were hospitalized during the same period of time with community-acquired pneumonia (CAP) not caused by M. pneumoniae (non-MP-CAP). MP was the second most common etiology (29.2%) in all CAP patients, and the most common etiological agent (43.2%) in the 17- to 44-year age group. In 65 patients (64.3%) at least one other pathogen was identified for CAP in addition to MP. Although the disease was most prevalent among younger patients, it also involved older and even elderly patients. Compared to non-MP-CAP patients, the severity of disease was significantly lower on average in the MP-CAP group and the length of hospitalization was significantly shorter. Radiologic findings were the same in the two groups. Twenty-two MP-CAP patients recovered without receiving the treatment which is recognized as effective in this disease. We concluded that (1) in most patients with MP-CAP a second CAP pathogen can be identified serologically, (2) MP-CAP cannot be differentiated from non-MP-CAP on the basis of clinical, radiologic, or routine laboratory tests, and (3) in some MP-CAP patients the disease is self-limited, and in these patients the usefulness of standard antibiotic therapy is doubtful.