HAEMOPHILUS INFLUENZAE, INVASIVE DISEASE

Question 1

Invasive disease caused by Haemophilus influenzae. It may produce any of several clinical syndromes including meningitis, bacteremia (i.e., presence of bacteria in the blood), epiglottitis (i.e., inflammation of the cartilage that covers the trachea), or pneumonia. Invasive infection does NOT include conjunctivitis.

Answer 1

HAEMOPHILUS INFLUENZAE, INVASIVE DISEASE

Question 2

Laboratory Criteria requirements

Answer 2

Any of the following:
• Isolation of H. influenzae from a normally sterile site (e.g., blood or cerebrospinal fluid [CSF]; or less
commonly, from joint, pleural, or pericardial fluid);
• A positive result on an NHI and API/NH antigen tests (now considered adequately sensitive and specific to be
used for diagnosis); or
• A positive result on a FDA-approved polymerase chain reaction (PCR)–based diagnostic test.

Question 3

Probable or confirmed?

Meningitis with detection of Haemophilus influenzae type b antigen in cerebrospinal fluid (CSF).

Answer 3

Probable.