Haemophilus influenzae Invasive Disease, 2001

Fifty-six cases of invasive Haemophilus influenzae disease (1.2 per 100,000 population) were reported in 2001. Case-patients ranged in age from newborn to 89 years, (median, 63 years). Nineteen (34%) had pneumonia, 22 (39%) had bacteremia without another focus of infection, four (7%) had meningitis, and 11 (20%) had other conditions. Twelve (21%) deaths were reported among these cases.

Only one case was known to be type b (Hib), compared to three cases in 2000 and five cases in 1999. The Hib case reported in 2001 occurred in a 5-year-old with a complete vaccine history and no underlying medical conditions. Epiglottitis was the type of infection, and the patient survived.

Nineteen (34%) of the Haemophilus influenzae isolates were not available for typing at MDH. Of the total 37 isolates for which typing was performed (including the one [3%] type b isolate described previously), six (16%) were type f, four (11%) were type d, two (5%) were type a, one (3%) was type e, and 23 (62%) were untypeable isolates.

The 12 deaths occurred in patients ranging in age from 9 months to 89 years. Six cases presented with pneumonia, three with bacteremia without another focus of infection, two with meningitis, and one with cellulitis. Ten cases had H. influenzae isolated from blood, and two had the pathogen isolated from cerebrospinal fluid. Eleven were known to have underlying medical conditions. Isolates from one of the deaths was type d; nine were untypeable isolates, and two isolates were not available at MDH 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, 2001