Bronchiolitis Associated with Mycoplasma pneumoniae Infection in Infants in Foshan China: An Epidemiologic Study

BACKGROUND: Bronchiolitis is common in infants under 2 years of age. Most infections are caused by respiratory syncytial virus (RSV), but the importance of Mycoplasma pneumoniae (MP) in the etiology of bronchiolitis is unclear. MATERIAL/METHODS: We investigated the clinical characteristics of bronchiolitis caused by MP in 79 infants admitted to Shunde Women’s and Children’s Hospital of Guangdong Medical University and Sanshui Women’s and Children’s Healthcare Hospital from January 2016 to December 2018. Infection with MP was confirmed by the presence of serum immunoglobulin M. RESULTS: The peak detection rates of MP in the years 2016, 2017, and 2018 were 19.2%, 21.3%, and 24.0%, respectively. In each year, the peak of MP infections occurred during June and July. MP-associated bronchiolitis was mainly seen in infants from 6 to 12 months of age. Compared with RSV-associated bronchiolitis, the age of patients with bronchiolitis associated with MP was significantly older and they had a shorter hospital stay (all P<0.01 or P<0.05). CONCLUSIONS: Our study indicated that MP is an important cause of bronchiolitis, with peaks of occurrence during June and July every year. Pulmonary interstitial infiltration was a characteristic of this infection. Azithromycin treatment can shorten the course of MP-associated bronchiolitis. Investigation of the epidemiological characteristics of pediatric MP-associated bronchiolitis can help diagnose and treat the disease correctly.