title: Seroprevalence of mumps in an epidemic period in Medellín, Colombia.
abstract: OBJECTIVE
  We related seroprevalence and outbreaks data in order to identify factors that could explain the occurrence of outbreaks despite high vaccination coverage in Medellín Colombia.
  
  
  METHODS
  Samples from a population seroprevalence data obtained in 2009 in a random survey were analyzed. IgG levels were determined for mumps using 2 commercial tests of 2119 individuals aged 6-64 years. A comparative analysis was undertaken using age-specific mumps seroprevalence data and information of 98 epidemiological investigations of mumps outbreaks reported in 2009.
  
  
  RESULTS
  Overall, seroprevalence was 91.6% (95% CI=89.3-93.5%). The age-specific seronegativity was 20.3% and 20.6% in age groups 11-15 years and 16-20 years respectively. Individuals aged 6-20 years were the most affected during outbreaks. In individuals born in 2003, a year after the change in the booster schedule from 10 to 5 years, the proportion of unvaccinated individuals (14%) and those who received only one dose of MMR (45%) increased substantially. On average, 23.5 days elapsed between the onset of symptoms in secondary cases and the outbreak investigation.
  
  
  CONCLUSIONS
  Potential contributing factors for the occurrence of outbreaks of mumps were the relatively high prevalence of seronegativity among individuals aged 11-20 years, delays in investigation and control of outbreaks, and incomplete vaccination schedules.
authors.affiliation: Secretary of Health, Medellín, Colombia. Electronic address: santacruzsanmartin@yahoo.com.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Santacruz-Sanmartín
authors.affiliation: Epidemiology Group, National School of Public Health, 'Héctor Abad Gómez', University of Antioquia, Medellín, Colombia. Electronic address: doracely@gmail.com.
authors.forename: Doracelly
authors.initials: D
authors.lastname: Hincapié-Palacio
authors.affiliation: Laboratory of Public Health of the Regional Secretary of Health and Social Protection of Antioquia, Medellín, Colombia. Electronic address: martha.ospina@antioquia.gov.co.
authors.forename: Marta C
authors.initials: MC
authors.lastname: Ospina
authors.affiliation: Laboratory of Public Health of the Regional Secretary of Health and Social Protection of Antioquia, Medellín, Colombia. Electronic address: olgaperez11@hotmail.com.
authors.forename: Olga
authors.initials: O
authors.lastname: Perez-Toro
authors.affiliation: Laboratory of Public Health of the Regional Secretary of Health and Social Protection of Antioquia, Medellín, Colombia. Electronic address: luzmarinabernal312@hotmail.com.
authors.forename: Luz M
authors.initials: LM
authors.lastname: Bernal-Restrepo
authors.affiliation: Laboratory of Public Health of the Regional Secretary of Health and Social Protection of Antioquia, Medellín, Colombia. Electronic address: seti.buitrago@antioquia.gov.co.
authors.forename: Seti
authors.initials: S
authors.lastname: Buitrago-Giraldo
authors.affiliation: National School of Public Health, 'Héctor Abad Gómez', University of Antioquia, Medellín, Colombia. Electronic address: vileba15@gmail.com.
authors.forename: Viviana
authors.initials: V
authors.lastname: Lenis-Ballesteros
authors.affiliation: Inmunovirology Group, School of Medicine, University of Antioquia, Medellín, Colombia. Electronic address: francisco.diaz@udea.edu.co.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Díaz
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D003105:Colombia / Q000453:epidemiology; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D022542:Measles-Mumps-Rubella Vaccine / Q000008:administration & dosage; D008875:Middle Aged; D009107:Mumps / Q000453:epidemiology*; D015995:Prevalence; D016036:Seroepidemiologic Studies; D014611:Vaccination / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D022542:Measles-Mumps-Rubella Vaccine
keywords: Colombia; Disease outbreaks; Medellín; Mumps; Seroepidemiological studies