Prevalence of Mycoplasma and Chlamydia pneumonia in severe community-acquired pneumonia among hospitalized children in Thailand.

Pneumonia is the leading cause of pediatric morbidity and mortality worldwide, and Mycoplasma pneumoniae and Chlamydia pneumoniae are the two most common atypical pathogens. This study was designed to determine the prevalence and clinical impact of mycoplasma and chlamydia pneumonia in children hospitalized with severe pneumonia. Children 1 month-15 years old with a diagnosis of severe pneumonia (WHO criteria) were recruited between March 2005 and March 2006. Serologic studies were performed for anti-M. pneumoniae and anti-C. pneumoniae IgG/M on admission and 2-4 weeks afterward using ELISA. Of 52 patients, 13 (25%) were positive for Mycoplasma, 8 (15%) were positive for Chlamydia, 4 (7.6%) were positive for a mixed infection and 27 (52%) were negative. The subjects' mean age was 23.8+/-4.1 months. The mean of initial oxygen saturation on admission was 87.5+/-1.2%. Fever and prolonged cough were the leading symptoms. The mean of hospitalization was 18.8+/-2.6 days, chlamydia pneumonia had the longest duration, 30+/-10.2 days and 13/52 (25%) study subjects developed respiratory failure. Only 10% were treated with adequate antibiotic prior to serologic results. There was one mortality (1/52, 2%). Our study suggests that mycoplasma and chlamydia infections are commonly found among children hospitalized with severe pneumonia. Coverage with an appropriate antibiotic should be considered to hasten recovery.