title: Measles outbreak in Venezuela: a new challenge to postelimination surveillance and control?
abstract: The circulation of wild measles virus was interrupted in Venezuela in February 2007 after the catch-up vaccination (1994) and monitoring (1998) and in response to the measles outbreak in 2001. Traditionally, the routine coverage with measles-mumps-rubella vaccine does not exceed 85%. In February 2006, a measles outbreak started by importation in the State Miranda; this extended to 7 states and lasted 50 weeks with an intermediate period of 17 weeks without reported cases. New cases were reported in the States Guarico and Amazon. The pattern of circulation of the silent period was determined through the use of retrospective search for measles; this showed that 57% of suspected cases did not enter the surveillance system. Molecular epidemiology made it possible to identify B3 as only genotype, which also circulated in Spain. The epidemiological and clinical characteristics of measles have been modified; these determine outbreaks identified late, of slow expansion, silent, and with limited case-fatality, compared with classical outbreaks. The outbreak spread by that behavior was not recognized and the classical control measures did not result. The beginning of a broader and intense vaccination was delayed, partly by weaknesses in the sensitivity of the system. It is crucial to recognize the new behavior of measles and the effectiveness of the classical control measures, and especially to establish criteria for interruption of the circulation to control an outbreak in this stage of elimination.
authors.affiliation: National Directorate of Immunization, Bolivarian Republic of Venezuela.
authors.forename: Héctor
authors.initials: H
authors.lastname: Sarmiento
authors.forename: Oswaldo Barrezueta
authors.initials: OB
authors.lastname: Cobo
authors.forename: Ana
authors.initials: A
authors.lastname: Morice
authors.forename: Roger
authors.initials: R
authors.lastname: Zapata
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Benitez
authors.forename: Carlos
authors.initials: C
authors.lastname: Castillo-Solórzano
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003140:Communicable Disease Control / Q000266:history / Q000379:methods*; D004196:Disease Outbreaks / Q000517:prevention & control*; D054242:Emigrants and Immigrants; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D007223:Infant; D032541:Mass Vaccination; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control*; D022542:Measles-Mumps-Rubella Vaccine / Q000276:immunology*; D011159:Population Surveillance; D014195:Travel; D014687:Venezuela / Q000453:epidemiology; D055815:Young Adult
chemical_list: D022542:Measles-Mumps-Rubella Vaccine