Abstract:

To summarize the epidemiological and clinical characteristics of mycoplasm pneumonia (MP) infection in communityacquired lower respiratory tract infection (CALRTI) among hospitalized children. MethodsA retrospective analysis of a database of 876 patients with CALRTI at the Qilu Hospital of Shandong University between 2007 and 2008 was performed. Serologic diagnosis for MP infection was made based on single titers ≥1∶80, which was measured by a passive particle agglutination test. ResultsMP infection was diagnosed in 177 patients aged from 6 months to 14 years. The mean age was 5.1 years. Children older than 3 years accounted for 79.7％. The frequency of titer of MPIgM ≥1:320 was significantly higher in patients older than 3 years than in those younger than 3 (88/119 vs 25/58, 73.9% vs 43.1%). Prolonged cough and fever were leading symptoms. In children younger than 3 years, moderate fever and wheezes on auscultation are the main clinical features. Chest Xray showed typical radiological features such as peribronchial and perivascular interstitial infiltrates, with very few massive infiltrations. Extrarespiratory complications were rare.  In children older than 3 years, high fever and persistent dry cough were prominent features with less manifestation on auscultation. Massive infiltrations  and pleural infusion were often seen on chest Xray and extrarespiratory complications were common. ConclusionsMycoplasma pneumonia infection is frequent in children over 3 years among hospitalized CALRTI patients. The infective rate increases as the age increases. The infective rate in summer is significantly lower than that in spring, autumn and winter. The clinical features are obviously different between patients older and younger than 3 years.

Key words: Pneumonia, mycoplasma； Child；  Respiratory tract infections