Clinical characteristics of children with complicated pneumonia caused by Streptococcus pneumoniae.

OBJECTIVE: The frequency of children who are hospitalized with pneumococcal pneumonia complicated by necrosis, empyema/complicated parapneumonic effusion, and lung abscess seems to be increasing. The factors that contribute to this increase are unclear; therefore, the objective of this study was to describe and compare the relative frequency, clinical characteristics, and outcome of hospitalized children with complicated pneumonia with those of children with uncomplicated pneumonia caused by Streptococcus pneumoniae in the era of antibiotic resistance.
METHODS: A multicenter, retrospective study of 8 children's hospitals in the United States was undertaken. A total of 368 children who were hospitalized with pneumococcal pneumonia identified from patients enrolled in the US Pediatric Multicenter Pneumococcal Surveillance Study over the period from September 1, 1993, to January 31, 2000 were studied. Demographic and clinical variables, antibiotic susceptibility, pneumococcal serotypes, antimicrobial therapy, and clinical outcome in hospitalized children with complicated versus uncomplicated pneumococcal pneumonia were measured.
RESULTS: A total of 368 patients with pneumococcal pneumonia were identified. Of the 368 isolates, 47 (12.8%) were intermediate and 37 (10.1%) were resistant to penicillin; 18 (5%) were intermediate to ceftriaxone, and 9 (2.5%) were resistant to ceftriaxone. A total of 133 patients met the criteria for complicated pneumonia and had a chest tube placed; 56 of these patients subsequently underwent decortication. The proportion of hospitalized patients with complicated pneumococcal pneumonia increased progressively over the study period from 22.6% in 1994 to 53% in 1999. Patients with complicated disease were older (median age: 45 vs 27 months) and significantly more likely to be of white race and have chest pain on presentation compared with patients with uncomplicated disease. Patients who had complicated disease and underwent decortication were more likely to have pleural fluid lactate dehydrogenase levels of >7500 IU/L compared with those patients who had chest tube placement alone. Fifty-three percent of children who were > or =61 months of age and were hospitalized had complicated pneumonia. This group of children accounted overall for 42% of the patients with complicated pneumonia, 48.2% of the patients who subsequently underwent decortication, and 44% of the patients who had received a course of antibiotics before diagnosis. Pneumococcal serotypes 1, 6, 14, and 19 were the most prevalent serotypes causing disease, with serotype 1 causing 24.4% of the complicated cases versus 3.6% of the uncomplicated cases. Ninety-eight percent of the patients in both groups recovered from their pneumonia. Antibiotic resistance was not found to be more prevalent in those patients with complicated disease.
CONCLUSIONS: The relative frequency of complicated disease in hospitalized children with pneumococcal pneumonia is increasing. Patients with complicated pneumococcal disease were older and significantly more likely to be of white race compared with those patients with uncomplicated disease. Pneumococcal serotype 1 caused significantly more disease in patients with complicated versus uncomplicated pneumonia. Patients with complicated disease were not more likely to be infected with an antibiotic-resistant isolate.