Acute bacterial sinusitis complicating viral upper respiratory tract infection in young children

Background: Acute bacterial sinusitis (ABS) is a common complication of viral upper respiratory tract infections (URI). Clinical characteristics of URIs complicated by ABS in young children have not been well studied. Methods: We identified ABS episodes in a prospective, longitudinal cohort study of 294 children (6-35 months of age at enrollment), who were followed up for 1 year to capture all URI episodes and complications. At the initial URI visit seen by the study personnel (median day = 4 from symptoms onset), nasopharyngeal samples were obtained for bacterial cultures and viral studies. Results: Of 1295 documented URI episodes, 103 (8%) episodes (in 73 children) were complicated by ABS, 32 of which were concurrent with acute otitis media. The majority (72%) of ABS episodes were diagnosed based on persistent symptoms or a biphasic course. Average age at ABS diagnosis was 18.8 ± 7.2 months; White children were more likely to have ABS episodes than Blacks (P = 0.01). Hispanic/Latino ethnicity (P < 0.0001) was negatively associated, and adequate 7-valent pneumococcal conjugate vaccine immunization status (P = 0.001) appeared to increase the risk of ABS. Girls had more ABS episodes than boys (0.5 ± 0.8 vs. 0.3 ± 0.6 episodes/ yr, respectively, P = 0.03). Viruses were detected in 63% during the initial URI visit; rhinovirus detection was positively correlated with ABS risk (P = 0.01). Bacterial cultures were positive in 82/83 (99%) available samples obtained at the initial URI visit; polymicrobial (56%), Moraxella catarrhalis (20%) and Streptococcus pneumoniae (10%) were the most common cultures. Presence of pathogenic bacteria overall and presence of M. catarrhalis during URI were positively correlated with the risk for ABS (P = 0.04 for both). Conclusions: ABS complicates 8% of URI in young children. Girls have more frequent ABS episodes than boys. Presence of rhinovirus and M. catarrhalis during URI are positively correlated with the risk for ABS complication.