Reporting & Investigation of Hib Disease

Table of Contents

A. Purpose of Surveillance and Reporting 

  • To ensure that all cases of invasive Haemophilus influenza are typed and to identify all cases of Hib.

  • To identify household and child care contacts of Hib cases who need antimicrobial prophylaxis and/or immunization and to prevent further spread of the disease for Hib cases.

  • To distinguish between failure to vaccinate and vaccine failure.

B. Laboratory and Healthcare Provider Reporting Requirements

Iowa Administrative Code 641-1.3(139) stipulates that the laboratory and the healthcare provider immediately report any suspected or confirmed case. The reporting number for IDPH Center for Acute Disease Epidemiology (CADE) is (800) 362-2736, if you are calling after business hours you may call the Iowa State Patrol Office at (515) 323-4360 and they will page a member of the on-call CADE staff.

Note: Due to the potential severity and spread of invasive Haemophilus influenzae, IDPH requests that information about any case be immediately reported to the local public health agency where diagnosed. If this is not possible, call IDPH Center for Acute Disease Epidemiology (CADE) at (800) 362-2736.

What to Report to the Iowa Department of Public Health (IDPH)

  • A case clinically compatible with invasive Hib (e.g., with meningitis, bacteremia, epiglotittis, or pneumonia), as diagnosed by a healthcare professional, or

  • Isolation (culture) of Hib from a normally sterile body site (blood, cerebrospinal fluid (CSF), or less commonly joint, pleural, or pericardial fluid), or

  • Detection of Hib antigen in CSF.

Laboratory Testing Services Available 

Confirmation and serotyping of Haemophilus influenzae isolates are available at the University Hygienic Laboratory (UHL). All strains of Haemophilus influenzae isolated from normally sterile sites must be serotyped in order to identify the strain and to differentiate between serotype B and other serotypes, for which no control measures are necessary. Subcultures should be sent with a requisition form to UHL.  Call (319) 335-4500 for shipping directions.

Note: Positive antigen results from urine and/or serum samples are not reliable for diagnosis of Hib disease and should not be used as a substitute for culture results, but can help in determining immediate control measures while awaiting laboratory results.

C. Local Public Health Agency Follow-Up Responsibilities

If a case of Hib is identified, IDPH Center for Acute Disease Epidemiology (CADE) will become involved in the investigation and disease control recommendations, in collaboration with the local public health agencies. The infection control practitioner and the local public health agency should fax the lab report and/or other information to the CADE. The confidential fax number is (515) 281-5698. 

Case Investigation

  1. Ensure that typing of the Haemophilus influenzae isolate has been or is being done, preferably at the UHL.

  2. The local public health agency in conjunction the hospital infection control practitioner will collect pertinent information (demographic, clinical, exposure setting, transmission setting, detailed immunization history, and other pertinent history on the case) and record on the Bacterial Meningitis and Bacteremia Case Report Form. To assess and prepare for the possibility of a type b case, it is important to pay special attention to the case’s Hib vaccination history, whether the case had contact with another case of invasive Hib, whether a child care setting is involved, and the ages and Hib vaccination histories of children exposed to the case in the household and child care center.

  3. If type b is identified, notify CADE (800) 362-2736.After completing the investigation and gathering the information to complete the investigation form, enter information into IDSS, or FAX the report form with supporting laboratory documentation to (515) 281-5698 or mail (in an envelope marked “Confidential” to IDPH/CADE mailing address:
    • Iowa Department of Public Health, CADE
      Lucas State Office Building, 6th Floor
      321 E. 12th Street
      Des Moines, IA 50319-0075
  4. If type b is not identified, no additional control measures are necessary and a case investigation form does not need to be completed.