RESUMEN
Background: The prevalence of Chlamydia pneumoniae infection varies according to the population and geografic area studied. Aim: To evaluate the incidence of Chlamydia pneumoniae infection in Chilean subjects with community acquired pneumonia. Patients and methods: Between 1995 and 1997, patients with community acquired pneumonia attending two emergency rooms in Santiago, were studied. The diagnosis of Chlamydia pneumoniae infection was based on the detection of Chlamydia pneumoniae specific IgG antibody in samples from both the acute and convalescent phase, using an indirect microimmunofluorescent technique. Evidence of present infection was defined as seroconversion, a significant increase in the titer of the second sample and an initial titer equal or greater than 1/512. Results: During the study period, 160 patients consulted and seven (six male), aged 54ñ27 years old, complied with the diagnostic criteria of present Chlamydia pneumoniae infection. These patients had no special clinical or radiological features. Five of seven patients improved without any specific treatment. Conclusions: Eight percent of this sample of patients with community acquired pneumonia had Chlamydia pneumoniae infection. This agent should be included in the design of empiric treatment schemes, although our results cast doubt on the pathogenic role of Chlamydia pneumoniae in pneumonia