Changes in Neisseria meningitidis disease epidemiology in the United States, 1998-2007: implications for prevention of meningococcal disease.
BACKGROUND
In January 2005, a quadrivalent (serogroups A, C , Y, and W-135) meningococcal conjugate vaccine was licensed for use in adolescents. This report describes the epidemiologic features of meningococcal disease in the United States from January 1998 through December 2007, before and during implementation of adolescent quadrivalent meningococcal conjugate vaccination.


METHODS
Data were collected from active surveillance for invasive Neisseria meningitidis conducted through the Active Bacterial Core surveillance (ABCs) sites during 1998-2007. Isolates from cases were serogrouped at the ABCs site and confirmed at the Centers for Disease Control and Prevention. Estimates of the incidence and number of cases in the 50 states were calculated, standardizing for race and age group.


RESULTS
In the period 1998-2007, a total of 2262 cases of meningococcal disease were reported from ABCs sites; 11.3% of these cases were fatal. The estimated United States average annual incidence of meningococcal disease was 0.53 cases per 100,000 population (95% confidence interval, 0.51-0.55), and an estimated 1525 (95% confidence interval, 1470-1598) cases occurred annually. The annual incidence decreased 64.1%, from 0.92 cases per 100,000 population in 1998 to 0.33 cases per 100,000 population in 2007. Infants aged <1 year have the highest incidence of meningococcal disease (5.38 cases per 100,000 population). After introduction of the quadrivalent meningococcal conjugate vaccine, no significant decrease in serogroup C or Y meningococcal disease was seen among those aged 11-19 years in 2006-2007, compared with 2004-2005.


CONCLUSIONS
Before the introduction of the quadrivalent meningococcal conjugate vaccine, the incidence of meningococcal disease in the United States decreased to a historic low. However, meningococcal disease still causes a substantial burden of disease among all age groups. Future vaccination strategies may include targeting infants and preventing serogroup B meningococcal disease.
Cohn
Amanda C
AC
Meningitis and Vaccine Preventable Diseases Branch, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta Georgia 30333, USA. acohn@cdc.gov
MacNeil
Jessica R
JR
Harrison
Lee H
LH
Hatcher
Cynthia
C
Theodore
Jordan
J
Schmidt
Mark
M
Pondo
Tracy
T
Arnold
Kathryn E
KE
Baumbach
Joan
J
Bennett
Nancy
N
Craig
Allen S
AS
Farley
Monica
M
Gershman
Ken
K
Petit
Susan
S
Lynfield
Ruth
R
Reingold
Arthur
A
Schaffner
William
W
Shutt
Kathleen A
KA
Zell
Elizabeth R
ER
Mayer
Leonard W
LW
Clark
Thomas
T
Stephens
David
D
Messonnier
Nancy E
NE
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology* / Q000517:prevention & control*; D008875:Middle Aged; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult