Current Epidemiology and Trends in Invasive Haemophilus influenzae Disease-United States, 2009-2015

• Published in: Clinical infectious diseases Vol. 67; no. 6; pp. 881 - 889
• Main Authors: Soeters, Heidi M, Blain, Amy, Pondo, Tracy, Doman, Brooke, Farley, Monica M, Harrison, Lee H, Lynfield, Ruth, Miller, Lisa, Petit, Susan, Reingold, Arthur, Schaffner, William, Thomas, Ann, Zansky, Shelley M, Wang, Xin, Briere, Elizabeth C
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 31.08.2018
• Subjects: Adolescent; Adult; Age Factors; Aged; Child; Child, Preschool; Cost of Illness; Epidemiological Monitoring; Female; Haemophilus Infections - diagnosis; Haemophilus Infections - epidemiology; Haemophilus influenzae - isolation & purification; Haemophilus influenzae type b - immunology; Haemophilus Vaccines - therapeutic use; Humans; Incidence; Infant; Infant, Newborn; Male; Middle Aged; Public Health - trends; Serotyping; United States - epidemiology; Young Adult; United States; epidemiology; invasive disease; surveillance
• ISSN: 1058-4838; 1537-6591
• DOI: 10.1093/cid/ciy187

Invasive Haemophilus influenzae disease has increased, particularly due to nontypeable strains and serotype a. A considerable burden of invasive H. influenzae disease affects the oldest and youngest age groups, particularly American Indian and Alaska Native children. Abstract Background Following Haemophilus influenzae serotype b (Hib) conjugate vaccine introduction in the 1980s, Hib disease in young children dramatically decreased, and epidemiology of invasive H. influenzae changed. Methods Active surveillance for invasive H. influenzae disease was conducted through Active Bacterial Core surveillance sites. Incidence rates were directly standardized to the age and race distribution of the US population. Results During 2009-2015, the estimated mean annual incidence of invasive H. influenzae disease was 1.70 cases per 100000 population. Incidence was highest among adults aged ≥65 years (6.30) and children aged <1 year (8.45); many cases in infants aged <1 year occurred during the first month of life in preterm or low-birth-weight infants. Among children aged <5 years (incidence: 2.84), incidence was substantially higher in American Indian and Alaska Natives AI/AN (15.19) than in all other races (2.62). Overall, 14.5% of cases were fatal; case fatality was highest among adults aged ≥65 years (20%). Nontypeable H. influenzae had the highest incidence (1.22) and case fatality (16%), as compared with Hib (0.03; 4%) and non-b encapsulated serotypes (0.45; 11%). Compared with 2002-2008, the estimated incidence of invasive H. influenzae disease increased by 16%, driven by increases in disease caused by serotype a and nontypeable strains. Conclusions Invasive H. influenzae disease has increased, particularly due to nontypeable strains and serotype a. A considerable burden of invasive H. influenzae disease affects the oldest and youngest age groups, particularly AI/AN children. These data can inform prevention strategies, including vaccine development.