Clinical and epidemiological study of Mycoplasma pneumoniae and adenoviral pneumonia in a hospital of Barcelona

Introduction: Mycoplasma pneumoniae and adenovirus are two of the main causes of pneumonia in children. The objectives of the study are to describe the epidemiological, clinical, radiological and laboratory characteristics of the cases of pneumonia caused by these microorganisms in children younger than 15 years in a Hospital of Barcelona. And also to know if there are differences between both etiologies, between children with different ages and to know the cases of coinfections.

Methods: retrospective study of review of clinical histories of children under 15 who were visited from 2000 to 2007 in the hospital and whose IgM against M. pneumonia and/or adenovirus or the immunofluorescence or culture for adenovirus had been positive. A statistical study with the program SPSS was performed.

Results: seventy-three pneumonias caused by M. pneumoniae and 80 by adenovirus were diagnosed. Thirty-five were girls and 28 boys. The mean age was 5.7 and 3.5 years respectively; 46.6% were younger than 5 years in M. pneumoniae and 71.3% in adenovirus infections. There was no clear stational prevalence. The most frequent clinical manifestations were fever and cough, with good general aspect. The auscultatory findings were pathological in 141 cases, being crepitations and unilateral affectation the most frequent features. Chest x-rays showed predominantly unilateral affectation. Blood tests did not show significative alterations. There were 23 coinfections found with both microorganism and 22 with others.

Conclusions: M. pneumoniae and adenovirus should be considered causal agents of paediatric pneumonias. Is remarkable the difficulty in the differential diagnosis with other pneumonias, the clinical similitude between younger and older than 5 years and the important percentage of coinfections.