Epidemiology of Invasive Haemophilus influenzae Type a Disease in Alaska, 2018-2022

We used statewide surveillance data to describe the epidemiology of invasive Haemophilus influenzae type a disease in Alaska during 2018 to 2022. Of 52 cases identified, 39 (75%) occurred among Alaska Native children aged <5 years who lived in rural areas of southwest or northern Alaska. The average annual incidence was 17.8 per 100 000 among children aged <5 years vs 0.3 among persons aged ≥5 years. Among 43 cases in children aged <5 years, 16 (37%) presented with meningitis and 6 (14%) died. Characterizing H influenzae type a disease epidemiology can help direct prevention strategies, including vaccine development and use. From 2018 to 2022, Alaska reported 52 invasive Haemophilus influenzae type a cases, primarily in Alaska Native children aged <5 years in rural areas. The incidence was significantly higher in this group, with notably increased rates of meningitis and mortality.