Prevalence and clinical presentations of atypical pathogens infection in community acquired pneumonia in Thailand

Abstract

Objectives: To determine the prevalence of atypical pneumonia and clinical presentations in patients with community acquired pneumonia (CAP). Material and Method: A prospective multi-centered study was performed in patients aged ≥ 2 years with the diagnosis of CAP who were treated at seven governmental hospitals in Bangkok from December 2001 to November 2002. The diagnosis of current infection was based on ≥ 4 fold rise in antibody sera or persistently high antibody titers together with the presence of DNA of M.pneumoniae or C.pneumoniae in respiratory secretion or antigen of L. pneumophila in the urine. Clinical presentations were compared between patients with atypical pneumonia and unspecified pneumonia. Results: Of 292 patients, 18.8% had current infection with atypical respiratory pathogens (M. pneumoniae 14.0%, C.pneumoniae 3.4%, L.pneumophila 0.4% and mixed infection 1.0%). Only age at presentation was significantly associated with atypical pneumonia in adults, while absence of dyspnea, lobar consolidation, and age ≥ 5 years were significant findings for atypical pneumonia in children. Conclusion: The present study confirms the significance of atypical pathogens in adults and children. Moreover, lobar consolidation is likely to predict atypical pneumonia in childhood CAP.