Haemophilus influenzae Disease Surveillance and Trends

An illustration of data.

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.

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

Figure 1 shows estimated incidence rates (per 100,000 persons) <a href=

of invasive H. influenzae disease caused by serotype b, other serotypes excluding b, and nontypeable bacteria in the United States from 1989 through 2022." /> This figure shows estimated incidence rates (per 100,000 persons) <a href=

This figure shows estimated incidence rates (per 100,000 persons) <a href=

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." />

Data reporting

Data definitions

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