Haemophilus influenzae Invasive Disease, 2014

One hundred twenty-three cases of invasive Haemophilus influenzae disease (2.3 per 100,000 population) were reported in 2014. Invasive H. influenzae increased from 1.5 cases per 100,000 in 2010 to 2.4 cases per 100,000 in 2014. Cases ranged in age from newborn to 102 years (median 69 years). Allowing for more than one syndrome per case, 60 (49%) cases had pneumonia, 40 (33%) had bacteremia without another focus of infection, 8 (7%) had septic shock, 8 (7%) had meningitis, 4 (3%) had cellulitis, 2 (2%) had epiglottitis, 3 (2%) had septic arthritis, 1 (<1%) each had abscess, chorioamnionitis, osteomyelitis, otitis media, peritonitis, and septic abortion. Fifteen (12%) cases died.

Of 117 H. influenzae isolates for which typing was performed at PHL, 16 (14%) type a, 15 (13%) were type f, 1 (<1%) type b, 6 (5%) type e, and 79 (68%) were untypeable. One case of type b (Hib) disease occurred in 2014, compared to 4 cases in 2013, 3 cases in 2012, and 3 cases in 2011. The case was in a child < 1 year of age who had received 1 dose of Hib vaccine. The case had meningitis and survived.

The 15 deaths occurred in patients ranging in age from 2 to 93 years. Ten cases had pneumonia (of these 3 also had septic shock), and 5 had bacteremia without focus (of these 1 also had septic shock). All 15 cases had H. influenzae isolated from blood and 13 had underlying medical conditions. Of these 15 deaths, 11 case-isolates were untypeable; 1 each was serotype a, e, and f; and 1 was not available for serotyping.

• For up to date information see>> Haemophilus influenzae (invasive disease)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2014