Bacterial infection complicating varicella infection: A 10-year review of hospitalized children.

An increased incidence of Streptococci pyogenes (group A streptococcus [GAS]) infections and rheumatic fever has been reported over the past decade. The present study was conducted to determine whether a similar increase in such infections was observed after varicella, an infection previously shown to be associated with a high incidence of streptococcal infections. The charts of all children admitted with chickenpox to the Hospital for Sick Children in Toronto, Ontario from January 1, 1980 to December 31, 1989 were reviewed. Immunocompromised children and those hospitalized for another reason who had an incidental diagnosis of chickenpox were excluded. Twenty-five cases with bacterial infection complicating chickenpox were compared with 103 patients without secondary infection. No statistically significant differences were observed for age, gender, duration of illness prior to hospitalization or duration of hospitalization in the two groups. GAS was the most frequent isolate in the cases, followed by Staphylococcus aureus, Escherichia coli and Haemophilus influenzae. The types of infection were significantly different for GAS compared with other organisms, with a predominance of skin infections in the former group (χ(2) analysis, P<0.05). No increase in the incidence of GAS infections was observed over time. This study confirms the importance of GAS infections in patients with varicella, but no increase was observed in hospitalized children during the 10-year study period.