Epidemiology and associations with climatic conditions of Mycoplasma pneumoniae and Chlamydophila pneumoniae infections among Chinese children hospitalized with acute respiratory infections

Abstract

Doc number: 34

Abstract

Background: The incidence of severe acute respiratory tract infections in children caused by Mycoplasma pneumoniae (syn. Schizoplasma pneumoniae ) and Chlamydophila pneumoniae (formerly Chlamydia pneumoniae ) varies greatly from year to year and place to place around the world. This study investigated the epidemiology of M . pneumoniae and C . pneumoniae infections among children hospitalized with acute respiratory infections in Suzhou, China in the year 2006, and associations between incidence rates and climatic conditions.

Methods: Nasopharyngeal aspirates obtained from 1598 patients (aged 26.4 ± 28.3 months; range, 1 month to 13 years) were analyzed with real-time PCR and ELISA. Meteorological data were obtained from the weather bureau.

Results: About 18.5% of patients were infected with M . pneumoniae and, C . pneumoniae , or both. Isolated M . pneumoniae infection was positively correlated with increasing age (χ² = 34.76, P < 0.0001). Incidence of M . pneumoniae infection was seasonal with a peak in summer (P < 0.0001) and minimum in winter (P = 0.0001), whereas C . pneumoniae infection was low only in autumn (P = 0.02). Monthly mean temperature was strongly correlated with the incidence of M . pneumoniae infection (r = 0.825, P = 0.001).

Conclusions: M . pneumoniae and C . pneumoniae are important infectious agents in hospitalized children with acute respiratory tract infections. M . pneumoniae infection showed a strong direct correlation with environmental temperature.