Burden of disease caused by Haemophilus influenzae type b in children younger than 5 years: global estimates.
BACKGROUND
Haemophilus influenzae type b (Hib) is a leading cause of childhood bacterial meningitis, pneumonia, and other serious infections. Hib disease can be almost completely eliminated through routine vaccination. We assessed the global burden of disease to help national policy makers and international donors set priorities.


METHODS
We did a comprehensive literature search of studies of Hib disease incidence, case-fatality ratios, age distribution, syndrome distribution, and effect of Hib vaccine. We used vaccine trial data to estimate the proportion of pneumonia cases and pneumonia deaths caused by Hib. We applied these proportions to WHO country-specific estimates of pneumonia cases and deaths to estimate Hib pneumonia burden. We used data from surveillance studies to develop estimates of incidence and mortality of Hib meningitis and serious non-pneumonia, non-meningitis disease. If available, high-quality data were used for national estimates of Hib meningitis and non-pneumonia, non-meningitis disease burden. Otherwise, estimates were based on data from other countries matched as closely as possible for geographic region and child mortality. Estimates were adjusted for HIV prevalence and access to care. Disease burden was estimated for the year 2000 in children younger than 5 years.


RESULTS
We calculated that Hib caused about 8.13 million serious illnesses worldwide in 2000 (uncertainty range 7.33-13.2 million). We estimated that Hib caused 371,000 deaths (247,000-527,000) in children aged 1-59 months, of which 8100 (5600-10,000) were in HIV-positive and 363,000 (242,000-517,000) in HIV-negative children.


CONCLUSIONS
Global burden of Hib disease is substantial and almost entirely vaccine preventable. Expanded use of Hib vaccine could reduce childhood pneumonia and meningitis, and decrease child mortality.


BACKGROUND
GAVI Alliance and the Vaccine Fund.
Watt
James P
JP
Hib Initiative, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. jwatt@jhsph.edu
Wolfson
Lara J
LJ
O'Brien
Katherine L
KL
Henkle
Emily
E
Deloria-Knoll
Maria
M
McCall
Natalie
N
Lee
Ellen
E
Levine
Orin S
OS
Hajjeh
Rana
R
Mulholland
Kim
K
Cherian
Thomas
T
D016667:Bacterial Capsules; D046688:Child Mortality; D002675:Child, Preschool; D018672:Community Health Planning; D017281:Cost of Illness; D014943:Global Health; D015658:HIV Infections / Q000453:epidemiology; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000517:prevention & control; D018073:Haemophilus Vaccines; D019741:Haemophilus influenzae type b; D006801:Humans; D015994:Incidence; D007223:Infant; D008583:Meningitis, Haemophilus / Q000453:epidemiology* / Q000517:prevention & control; D009017:Morbidity; D018410:Pneumonia, Bacterial / Q000453:epidemiology* / Q000517:prevention & control; D011159:Population Surveillance; D014611:Vaccination
D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine