Acute epiglottitis: epidemiology and Streptococcus pneumoniae serotype distribution in adults

Objectives: We studied the incidence and bacterial epidemiology of acute epiglottitis presenting in the first 16 years following the introduction of general childhood vaccination against Haemophilus influenzae type b. Our main objectives were to analyse (1) the incidence of Streptococcus pneumoniae epiglottitis in adults and (2) the distribution of pneumococcal serotypes involved. Materials and methods: The medical records of patients with acute epiglottitis (International Classification of Disease code J05.1) were investigated. Streptococcus pneumoniae serotyping was performed using gel precipitation. Results: The overall incidence of acute epiglottitis was 0.98 cases/100 000/year, compared with 4.5 cases/100 000/year before the vaccination programme. The incidence was reduced both in children and adults, compared with pre-vaccination values. However, the incidence of Streptococcus pneumoniae epiglottitis in adults increased from 0.1 to 0.28 cases/100 000/year over the same time period. The causative agent was Streptococcus pneumoniae in 10 adults. Nine of 10 pneumococcal strains could be serotyped. All but one serotype is represented in the 23-valent pneumococcal polysaccharide vaccine (PPV23) used in adults. Conclusion: In acute epiglottitis, now a disease of adults, the most important bacterial aetiology is Streptococcus pneumoniae. The serotype distribution found in this study indicates that the infection is preventable by PPV-23 vaccination with the 23-valent polysaccharide vaccine.