Haemophilus influenzae Disease Surveillance and Trends

Key points

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

Data systems

National Notifiable Diseases Surveillance System

Invasive H. influenzae disease is a nationally notifiable disease.

CDC collects national information about invasive H. influenzae disease through the National Notifiable Diseases Surveillance System (NNDSS). CDC receives NNDSS data each week.

Keep Reading: Learn More About NNDSS

Active Bacterial Core surveillance

CDC also collects information from laboratories in 10 areas of the country through Active Bacterial Core surveillance (ABCs). ABCs is part of CDC's Emerging Infections Program.

Keep Reading: Active Bacterial Core surveillance (ABCs)

Bact Facts Interactive‎

You can analyze and visualize ABCs H. influenzae data.
Use Bact Facts Interactive

How the data are interpreted

Disease trends

The epidemiology of invasive H. influenzae disease has changed since the United States began using Hib vaccines. Hib vaccination began for children in 1987 and for infants in 1990.

Since then, the annual incidence of invasive disease in children younger than 5 years old has changed:

  • Type b: Decreased by 99%
  • Non-b: Increasing (primarily types a and f)
  • Nontypeable: Increasing
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Figure 1 shows estimated incidence rates (per 100,000 persons) of invasive H. influenzae disease caused by serotype b, other serotypes excluding b, and nontypeable bacteria in the United States from 1989 through 2022.
Invasive Hib disease remains low, while disease caused by non-b and nontypeable bacteria were increasing until 2020.
SOURCE:

Active Bacterial Core surveillance

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This figure shows estimated incidence rates (per 100,000 persons) of invasive H. influenzae disease by serotype and age in the United States from 2018 through 2022. Children younger than 1 year old and adults older than 65 years old have the highest incidence of H. influenzae disease. Across age groups, nontypeable bacteria cause the highest incidence of H. influenzae disease.
From 2018 through 2022, incidence is highest among young children (<1 year) and older adults (65+ years) and for nontypeable bacteria.
SOURCE:

Active Bacterial Core surveillance

Data reporting

View NNDSS infectious disease data tables.

View ABCs annual reports for H. influenzae disease.

Data definitions

The Council of State and Territorial Epidemiologists (CSTE) released the most recent case definition for H. influenzae disease in 2015.

Resources

H. influenzae type b chapter of the Manual for the Surveillance of Vaccine-Preventable Diseases

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Content Source:
National Center for Immunization and Respiratory Diseases; Division of Bacterial Diseases