Haemophilus influenzae disease - Annual Epidemiological Report for 2023

Surveillance and monitoring
Publication series: Annual Epidemiological Report
Time period covered: This report is based on data for 2023 retrieved from EpiPulse Cases on 12 March 2025.
Cite:

European Centre for Disease Prevention and Control. Annual Epidemiological Report for 2023 – Haemophilus influenzae disease. Stockholm: ECDC; 2025.

In 2023, 5 234 confirmed cases of invasive Haemophilus influenzae disease were reported in the EU/EEA, representing a continued increase compared to the previous year (3 983 in 2022) and a substantial rise from pandemic-era figures (1 693 in 2021, 1 838 in 2020), coinciding with the post-COVID-19 return to typical respiratory disease transmission patterns.

  • The notification rate rose to 1.2 cases per 100 000 population, the highest observed in the past five years, up from 0.9 in 2022 and 0.4 in both 2020 and 2021.
  • Age-specific rates remained highest among infants under one year of age (6.41 per 100 000 population), followed by those aged 65 years and older (3.2 per 100 000 population).
  • Serotyping data were available for 60% of cases. Among cases with known serotype, non-capsulated strains continued to dominate, accounting for 81% of infections. Serotype f was the most frequent capsulated strain, responsible for 6% (194 cases) of all cases, followed by serotype b 5% (164 cases)
  • In 2023, serotype b (Hib) represented 5% of known serotyped cases, reflecting a slight decline from 9.1% in 2022. The low proportion of serotype b (Hib) reported continues to reflect the strong effect of the Hib vaccination programmes in EU/EEA countries.

All annual epidemiological reports on Haemophilus influenzae disease