Large outbreak of measles in a community with high vaccination coverage: implications for the vaccination schedule.
BACKGROUND
Attempts to eliminate measles from a country or region may be disrupted by an imported case that affects indigenous persons. The objective of this study was to analyze epidemiological and clinical characteristics of a measles outbreak in Catalonia, Spain, in 2006.


METHODS
Data on cases of measles reported to the Department of Health, Generalitat of Catalonia, during the period 28 August 2006 through 8 July 2007 were collected. Suspected cases were confirmed by determination of measles-specific immunoglobulin M antibodies and/or detection of virus genome. Incidences were calculated using the estimated population of Catalonia for 2006, and 95% confidence intervals were determined assuming a Poisson distribution. The association between proportions was determined using the chi(2) test and Fisher's exact test. The level of statistical significance was set at alpha = .05.


RESULTS
A total of 381 cases were confirmed, for an incidence of 6.6 cases per 100,000 persons. A total of 89.5% of cases occurred in nonvaccinated persons, mainly those aged < or =15 months (incidence, 278.2 cases per 100,000 persons; mean age of patients, 12 months). Indigenous subjects accounted for 89.8% of cases, and laboratory confirmation of results was obtained for 87.1%. Measles genotype D4 was identified in all sequenced samples.


CONCLUSIONS
The age distribution of cases of measles among children aged <15 months suggests that the first dose of vaccine should be routinely administered at the age of 12 months.
Domínguez
Angela
A
Department of Public Health, University of Barcelona, Casanova 143, 08036 Barcelona, Spain. angela.dominguez@ub.edu
Torner
Nuria
N
Barrabeig
Irene
I
Rovira
Ariadna
A
Rius
Cristina
C
Cayla
Joan
J
Plasencia
Elsa
E
Minguell
Sofia
S
Sala
M Rosa
MR
Martínez
Ana
A
Costa
Josep
J
Mosquera
Mar
M
Cabezas
Carmen
C
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks / Q000517:prevention & control; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D008457:Measles / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control*; D008458:Measles Vaccine / Q000008:administration & dosage*; D008459:Measles virus / Q000235:genetics / Q000302:isolation & purification; D008875:Middle Aged; D013030:Spain / Q000453:epidemiology; D013997:Time Factors; D014611:Vaccination
D008458:Measles Vaccine