1363. Assessment and Quantification of Nasopharyngeal Streptococcus pneumoniae Colonization Does Not Discriminate Between Children with Viral and Bacterial Respiratory Infection

BACKGROUND: Pediatric uncomplicated pneumonia can be caused by viruses, bacteria, and atypical pathogens. Unfortunately, readily-available diagnostics do not reliably identify which cases of uncomplicated pneumonia have a bacterial etiology. It has been suggested that measuring pneumococcal nasopharyngeal carriage can discriminate between viral and bacterial disease. The objective of this study was to determine if nasopharyngeal pneumococcal carriage differed between children with definite viral disease, definite bacterial disease, and respiratory disease of indeterminate etiology. METHODS: Three cohorts were recruited. Cohort 1 consisted of children with acute respiratory illness admitted to the pediatric intensive care unit; Cohort 2 consisted of previously healthy children with acute respiratory illness admitted to the general pediatric ward; and Cohort 3 consisted of previously healthy children diagnosed with non-severe community-acquired pneumonia in the emergency department. Children were categorized into the following disease categories: a) viral infection syndrome, b) pneumonia complicated by effusion/empyema, or c) ‘indeterminate’ pneumonia. Study subjects’ nasopharyngeal swabs (NPS) underwent quantitative PCR testing for S. pneumoniae. RESULTS: There were 206 children in Cohort 1, 122 children in Cohort 2, and 179 children in Cohort 3. The median subject age was 2.5 y (25-75%ile 1.3-4.9 y). Only a minority (227/507, 45%) had pneumococcal carriage detected; in those participants, there was no association of quantitative genomic load with age, cohort, or disease category. In multivariate logistic regression, NPS pneumococcal carriage (positivity >3 log copies/mL) was associated with younger age and cohort of recruitment, but not with disease category (all those with indeterminate non-severe pneumonia were from Cohort 3). Table 1. Comparison of subjects in different cohorts [Image: see text] Table 2. Comparison of subjects in different disease categories [Image: see text] Table 3. Associations with nasopharyngeal pneumococcal colonization >3 log copies/mL. [Image: see text] CONCLUSION: The nasopharyngeal S. pneumoniae carriage patterns of subjects with definite viral infection were very similar to those with definite bacterial infection and to those with indeterminate pneumonia. It would therefore appear that assessment and quantification of nasopharyngeal pneumococcal colonization is not useful to discriminate between acute viral and bacterial respiratory disease in children in North America. DISCLOSURES: All Authors: No reported disclosures