Concurrent influenza A and group A beta-hemolytic streptococcal pharyngotonsillitis

Objectives: A concurrent group A beta-hemolytic Streptococcus (GABHS)-influenza virus pharyngotonsillitis (PT) is generally not considered in diagnoses, even though mixed bacterial-viral infections are common in other respiratory tract infections. This report describes our experience in diagnosing a potential mixed GABHS-influenza virus PT in children. Methods: Acute and convalescent antistreptolysin O (ASO) and anti-DNase B titers were obtained from 12 children with acute PT and clinical presentation that suggested viral infection, and in whom both rapid influenza A virus and rapid GABHS tests were positive. Results: The children did not receive any antimicrobial therapy, and all recovered from their acute PT within 2 to 5 days and were all asymptomatic upon their return visit 3 to 4 weeks later. GABHS was recovered from 2 of the children on their return visit. However, ASO and anti-DNase B titers were not elevated in these individuals. The ASO and anti-DNase B titers determined in the first serum samples were less than the age-adjusted normal values for all of the children. However, these titers rose by at least two-dilution (0.2 logarithm) in the convalescent sera as compared with the acute ones in 4 of the 12 children (33%). One of the 8 children who had no increase in ASO and anti-DNase B titers had an acute GABHS PT 5 months later. One-year follow-up of all of the children showed no anomalies. Conclusions: This report is the first to describe a concomitant GABHS and influenza A virus PT, as evident by increased ASO and anti-DNase B titers in a third of the patients who had both of these organisms detected in their upper airways.