National case definition: Haemophilus influenzae serotype b, invasive disease
Haemophilus influenzae serotype b, invasive disease
Date of last revision/review: May 2008
Only confirmed cases of disease should be notified.
Type of surveillance
Routine case-by-case notification to the federal level
Enhanced case-by-case notification to International Circumpolar Surveillance in participating Northern regions
Enhanced, active case-by-case notification by paediatric tertiary care hospitals involved in the Immunization Monitoring Program, Active (IMPACT)
Clinical evidence of invasive disease (see Clinical evidence section) with laboratory confirmation of infection:
- isolation of H. influenzae (serotype b) (Hib) from a normally sterile site
- isolation of H. influenzae (serotype b) from the epiglottis in a person with epiglottitis
Clinical evidence of invasive disease with laboratory evidence of infection:
- demonstration of H. influenzae type b antigen in cerebrospinal fluid
- demonstration of H. influenzae DNA in a normally sterile site
- buccal cellulitis or epiglottitis in a child < 5 years of age with no other causative organisms isolated
Detection of H. influenzae DNA is considered probable, not confirmed, because Hib may be present in a non-pathogenic role and thus, depending on the site, may NOT reflect the actual pathogen. Additionally, detection of H. influenzae DNA in a sterile site does NOT indicate that it is type b, since this test does not differentiate between serotypes.
Clinical illness associated with invasive disease due to H. influenzae includes meningitis, bacteraemia, epiglottitis, pneumonia, pericarditis, septic arthritis and empyema.
Note: ICD codes do not differentiate between b and non-b serotypes
A41.3 Septicaemia due to Haemophilus influenzae
A49.2 H. influenzae infection, unspecified site
B96.3 H. influenzae as cause of disease classified elsewhere
G00.0 Meningitis due to Haemophilus influenzae
J05.1 Acute epiglottitis
J14 Pneumonia due to Haemophilus influenzae
P23.6 Congenital pneumonia due to Haemophilus influenzae
038.41 Septicaemia due to Haemophilus influenzae
041.5 H. influenzae infection of unspecified site and in conditions classified elsewhere
320.0 Meningitis due to Haemophilus influenzae
464.3 Acute epiglottitis
482.2 Pneumonia due to Haemophilus influenzae
Probable case definitions are provided as guidelines to assist with case finding and public health management, and are not for national notification purposes.
Between 1979 and 1985, only H. influenzae type b (Hib) meningitis was nationally notifiable. Beginning in 1986, all invasive forms of H. influenzae type b disease were nationally notifiable. Current vaccination programs only provide protection against Hib.
Although rare, increasingly non-b serotypes of H. influenzae have been found to cause invasive disease in Canada. Cases with clinically compatible illness and isolation of non-b serotypes of H. influenzae are also nationally notifiable (see Haemophilus influenzae non-b, Invasive Disease).
Previous case definitions
Canadian Communicable Disease Surveillance System: disease-specific case definitions and surveillance methods. Can Dis Wkly Rep 1991;17(S3).
Case definitions for diseases under national surveillance. CCDR 2000;26(S3).
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