CDC tracks invasive Haemophilus influenzae disease using 2 surveillance systems. Invasive disease refers to when the bacteria invade parts of the body, like blood, that are normally free from germs. CDC does not track non-invasive H. influenzae disease, such as ear infections.

National Notifiable Diseases Surveillance System

CDC conducts national surveillance for invasive H. influenzae disease through the National Notifiable Diseases Surveillance System (NNDSS). CDC receives NNDSS data weekly regarding cases of nationally notifiable diseases.


Bact Facts Interactive
magnifying glass with bacteria symbol

Analyze and visualize ABCs H. influenzae data using Bact Facts Interactive.

Active Bacterial Core surveillance

CDC also tracks invasive H. influenzae disease with active laboratory-based surveillance through Active Bacterial Core surveillance (ABCs). As part of the Emerging Infections Program, ABCs aims to:

  • Determine the incidence and epidemiologic characteristics of invasive H. influenzae disease
  • Monitor impact of the H. influenzae type b vaccination program
  • Detect possible emergence of disease due to non-type b H. influenzae
  • Determine appropriate verification and validation criteria for serotyping

View ABCs annual reports for H. influenzae disease.


Page last reviewed: February 13, 2020