title: Increasing mumps incidence rates among children and adolescents in the Republic of Korea: age-period-cohort analysis.
abstract: BACKGROUND
  To characterize the temporal dynamics of mumps epidemiology according to the different vaccine strains used, sex-specific trends were decomposed in an age-period-cohort (APC) analysis for mumps cases reported in South Korea.
  
  
  METHODS
  National surveillance data were used to describe the epidemiology of mumps cases from 2001 to 2015. An APC model was used to break down the reported mumps cases into the effects of age, period, and birth cohort.
  
  
  RESULTS
  From 2001 to 2015, the incidence started to increase from fewer than 10 cases to more than 100 cases per 100 000. The incidence rate was highest among males aged 15-17 years during 2013-2015, reaching 508.7 per 100 000 persons. There was an increased incidence during the late teenage years in the 1998-2000 cohort. An age shift towards the earlier teenage years was observed across the 2001-2003 and 2004-2006 cohorts. The risk of mumps increased according to the birth cohort; the net drift from 2001 to 2015 was 27.67 (95% confidence interval 27.5.47-29.90) for males and 27.25 (95% confidence interval 24.91-29.65) for females.
  
  
  CONCLUSIONS
  The increase in mumps seen in Korea may have been affected by the birth cohort exposed to the Rubini strain; however other factors may have contributed to the increase in non-exposed cohorts.
authors.affiliation: Medical Research Center, Seoul National University College of Medicine, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea; Department of Epidemiology, Seoul National University School of Public Health, Seoul, Republic of Korea.
authors.forename: Young-June
authors.initials: YJ
authors.lastname: Choe
authors.affiliation: Medical Research Center, Seoul National University College of Medicine, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea; Department of Epidemiology, Seoul National University School of Public Health, Seoul, Republic of Korea.
authors.forename: Young Hwa
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Medical Research Center, Seoul National University College of Medicine, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea; Department of Epidemiology, Seoul National University School of Public Health, Seoul, Republic of Korea. Electronic address: persontime@hotmail.com.
authors.forename: Sung-Il
authors.initials: SI
authors.lastname: Cho
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009107:Mumps / Q000453:epidemiology*; D056910:Republic of Korea / Q000453:epidemiology
keywords: Mumps; Rubini; Strain; Vaccine