Chima J. Ohuabunwo1, Kris Bisgard
2, Sue Bath
2, Pamela Srivastava
2, Nancy Rosenstein
3, Kathleen Shutt
4, and Trudy Murphy
2. (1) National Immunization Program, Epidemiology and Surveillance, CDC-Epidemiology Program Office/EIS, 1600 Clifton Road, NE, MS E-61, Atlanta, GA, USA, (2) National Immunization Program/ESD, Centers for Disease Control and Prevention, 1600 Clifton Road NE, MS E-61, Atlanta, GA, USA, (3) Centers for Disease Control and Prevention, National Immunization Program, Medical Epidemiologist, 1600 Clifton Road, NE, MS C-09, Atlanta, Georgia, USA, (4) Division of Bacterial and Mycotic Diseases, CDC, 1600 Clifton Road, Mailstop C-09, Atlanta, GA, USA
KEYWORDS:
Epidemiology, Surveillance,Hib, conjugate vaccines
BACKGROUND:
Before 1991 when Hib conjugate vaccines were recommended for infants, Haemophilus influenzae type b (Hib) was the leading cause of bacterial meningitis in young children
OBJECTIVE(S):
To review the Epidemiology of Hib invasive disease among children.
METHOD(S):
We analyzed data from nationally reported Haemophilus influenzae (Hi) invasive disease cases among children; data included Active Bacterial Core surveillance (ABCs) sites.
RESULT(S):
From 1998-2000, 824 Hi invasive disease cases were reported among children aged <5 years (average annual incidence: 1.5/100,000); serotype was reported for 81%. Of the 669 cases with known serotypes, Hib accounted for 197 (29%). The average annual Hib incidence was 0.34/100,000. Among the197 Hib case-patients, 86 (44%) were aged <6 months (incidence 4.6/100,000) and had not completed the 2- or 3-dose primary Hib vaccination series. Of 111 (56%) children aged > 6 months and eligible to have completed the series, 19 (17%) had unknown vaccination status; 31 (28%) were unvaccinated; 22 (20%) under-vaccinated; and 39 (35%) had completed the series (21 also received a booster dose). Hib incidence remained highest in Alaska (9.4/100,000) by state and Native American children (14.0/100,000). Among 169 Hib case-patients with known outcome, 14 (8%) died. None of these children had completed a primary Hib vaccination series; 11 aged <6 months were unvaccinated and 3 aged >6 months were under-vaccinated.
CONCLUSIONS(S):
Compared with the pre-vaccine era, Hib invasive disease in children aged <5 years has declined >99%; incidence is now highest in infants aged <6 months. Further reduction will require continued age-appropriate vaccination.
LEARNING OBJECTIVES:
Understand the current Epidemiology of Hib invasive disease among children in the U.S.
See more of Haemophilus influenzae, Polio, and Diphtheria: Experience in the US
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