Bronchiolitis associated with Mycoplasma pneumoniae in infants in Suzhou China between 2010 and 2012.

Viruses cause most cases of bronchiolitis in infants; consequently the importance of other agents such as Mycoplasma pneumoniae (MP) in the etiology of bronchiolitis may not be fully recognized. We investigated the prevalence and seasonal distribution of bronchiolitis caused by MP in 674 children admitted to the Children's Hospital affiliated with Soochow University from January 2010 to December 2012. The presence of MP was confirmed by real-time PCR. During the 3 years, we identified MP in 17.2% of the children with bronchiolitis. The annual MP detection rates were 16.6% in 2010, 17.8% in 2011, and 17.2% in 2012. MP was detected throughout the year, with a peak from July to September. The median age of MP-positive children was 10 months. Common clinical manifestations included cough, wheezing, and high fever. Moist and/or wheezing rales were frequent, and pulmonary interstitial infiltration was seen in 66.4% of chest X-rays. Patients with MP infection were older, were more likely to have pulmonary interstitial infiltration, and had shorter hospital stays than those with respiratory syncytial virus infection. Our study revealed MP as an important cause of bronchiolitis, with peaks of occurrence during the summer and early autumn. Pulmonary interstitial infiltrations were a common event.