Mycoplasma pneumoniae and Chlamydophila pneumoniae in children with community-acquired pneumonia in Thailand.

The prevalence of community-acquired pneumonia (CAP) caused by atypical pathogens in Thai children is unknown. The objective was to examine the prevalence of Mycoplasma pneumoniae and Chlamydophila pneumoniae infections in paediatric patients (aged 2-15 years) with CAP in three academic hospitals using standardised laboratory techniques. The characteristics of atypical pneumonia were also compared with other causes of CAP. Diagnosis of current infection was based on a four-fold or more rise in antibody serum samples or persistently high antibody titres together with the presence of mycoplasmal or chlamydial DNA in secretions. Of 245 patients with CAP 17.5% of cases were caused by atypical pathogens (M. pneumoniae 14.3% C. pneumoniae 2.8% and co-infection 0.4%). We also found atypical pathogens in young children aged 2-5 years. The clinical and laboratory findings did not distinguish atypical pneumonia from other CAPs. Segmental or lobar consolidation on chest X-rays was more common in atypical pneumonia while dyspnoea was more prominent in other CAPs. Our data show a high prevalence of M. pneumoniae and C. pneumoniae in Thai children with CAP including in children aged 2-5 years. (authors)