Viral coinfections in children with invasive pneumococcal disease.

Background: Respiratory viruses contribute to the seasonal pattern of invasive pneumococcal disease (IPD), but the impact of viral coinfections on the clinical characteristics and outcomes of patients with IPD have not been well defined.
Objective: This study was designed to describe and compare the clinical presentations and outcomes of patients with IPD with or without viral coinfections.
Design/methods: Retrospective analyses of records of all children treated at Children's Medical Center Dallas (CMCD) for IPD from July 2005 to June 2008. Viral studies included viral direct fluorescent antibody staining and culture. For comparisons, patients were classified in 3 groups: with positive, negative, and no viral studies performed.
Results: A total of 129 patients were admitted to CMCD with IPD during the 3 year study; 57% were male. Ages ranged from 2 months to 18 years (median 25 months) and 48% were <2 years. Viral studies were performed in 82 (63%) patients, and 28 (34%) had positive results. The most common viruses isolated were influenza (7, 25%), rhinoviruses (6, 21%), adenoviruses (6, 21%), and RSV (5, 18%). Peaks of positive viral studies occurred in February and November which coincided with the peak numbers of patients admitted with IPD. Of 6 with adenovirus coinfection, 5 were admitted to Pediatric Intensive Care Unit (PICU). The most common pneumococcal serotypes were 19A (41, 32.5%), 7F (14, 11%), and 23A (13, 10.3%). Pneumonia (42%), bacteremia (22%), and meningitis (17%) were the most common clinical syndromes. There were no differences in duration of fever before admission, maximum temperatures during hospitalization and white blood cell counts, duration of fever and hospitalization between patients with positive and negative viral studies, but there was a trend for patient with positive viral studies to be admitted to PICU more frequently and to have longer PICU stay. Three of the 6 patients who died had documented viral coinfections (2 adenovirus, 1 parainfluenza 3), and all 3 had no underlying conditions. The other 3 patients who died had no viral studies performed. Duration of treatment ranged from 1 to -210 days (median 14), with no differences among the groups.
Conclusions: Viral coinfections were common in children with IPD. Future prospective studies should include new PCR assays to characterize better the impact of viral coinfections in the occurrence and outcome of IPD.