Clinical Course and Outcomes of Invasive Haemophilus influenzae Infections among Children at Two Hospitals in Alaska.

Abstract

Our objective was to compare the clinical course of invasive Haemophilus influenzae disease by type among children at 2 hospitals in Alaska. We performed a retrospective review of invasive H. influenzae cases among Alaska children aged <10 years who received care at the Alaska Native Medical Center in Anchorage or the Yukon-Kuskokwim Delta Regional Hospital in Bethel, Alaska, during 2013-2019. Clinical and demographic data were obtained by medical record review. Categorical variables were compared with Fisher's exact test. We identified 62 invasive H. influenzae infections, including 45 (73%) type a (Hia), 8 (13%) type b (Hib), 7 (11%) nontypeable (NTHi), and 2 (3%) type f (Hif). All children were Alaska Native. Overall, 43 (69%) cases occurred in previously healthy children with no underlying medical conditions. Nineteen (31%) children required intensive care and 13 (21%) died or still had clinical sequelae at 1 year postinfection. All deaths (n = 6) and long-term sequelae (n = 7) occurred in children with Hia or Hib meningitis. Children with NTHi were more likely to require respiratory support compared with children with Hia, Hib, or Hif (6/7, 86% vs 15/55, 27%) (P < .01). We identified severe disease among Alaska Native children with invasive Hia, Hib, Hif, and NTHi infections. Hia and Hib caused more meningitis-associated fatalities, and NTHi caused more respiratory complications. Characterizing trends in invasive H. influenzae illness will help direct public health strategies, including the development and use of novel vaccines.