Measles outbreak in the Republic of the Marshall Islands, 2003.
BACKGROUND
Measles is a highly contagious viral infection. Measles transmission can be prevented through high population immunity (>or=95%) achieved by measles vaccination. In the Republic of the Marshall Islands (RMI), no measles cases were reported during 1989-2002; however, a large measles outbreak occurred in 2003. Reported 1-dose measles vaccine coverage among children aged 12-23 months varied widely (52-94%) between 1990 and 2000.


METHODS
RMI is a Pacific island nation (1999 population: 50,840). A measles case was defined as fever, rash, and cough, or coryza, or conjunctivitis, in an RMI resident between July 13 and November 7, 2003. A vaccination campaign was used for outbreak control.


RESULTS
Of the 826 reported measles cases, 766 (92%) occurred in the capital (Majuro). There were 186 (23%) cases in infants aged <1 year and 309 (37%) of cases in persons aged >or=15 years. The attack rate was highest among infants (Majuro atoll: 213 cases/1,000 infants). Among cases aged 1-14 years, 281 (59%) reported no measles vaccination before July 2003. There were 100 hospitalizations and 3 deaths. The measles H1 genotype was identified. The vaccination campaign resulted in 93% coverage among persons aged 6 months to 40 years. Interpretation Populations without endemic measles transmission can accumulate substantial susceptibility and be at risk for large outbreaks when measles virus is imported. 'Islands' of measles susceptibility may develop in infants, adults, and any groups with low vaccine coverage. To prevent outbreaks, high population immunity must be sustained by maintaining and documenting high vaccine coverage.
Hyde
Terri B
TB
Viral Vaccine Preventable Diseases Branch, National Immunization Program, NIP, Centers for Disease Control and Prevention, CDC, Atlanta, GA 30333, USA. thyde@cdc.gov
Dayan
Gustavo H
GH
Langidrik
Justina R
JR
Nandy
Robin
R
Edwards
Russell
R
Briand
Kennar
K
Konelios
Mailynn
M
Marin
Mona
M
Nguyen
Huong Q
HQ
Khalifah
Anthony P
AP
O'leary
Michael J
MJ
Williams
Nobia J
NJ
Bellini
William J
WJ
Bi
Daoling
D
Brown
Cedric J
CJ
Seward
Jane F
JF
Papania
Mark J
MJ
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D004198:Disease Susceptibility; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D032521:Immunity, Herd; D007223:Infant; D007231:Infant, Newborn; D008457:Measles / Q000150:complications / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage; D008875:Middle Aged; D010139:Pacific Islands / Q000453:epidemiology; D012574:Schools; D014186:Transportation; D014611:Vaccination / Q000706:statistics & numerical data
D008458:Measles Vaccine