Age, period, and cohort effects of Clonorchis sinensis infection prevalence in the Republic of Korea: Insights and projections

PLoS Negl Trop Dis. 2024 Oct 11;18(10):e0012574. doi: 10.1371/journal.pntd.0012574. eCollection 2024 Oct.

Abstract

Background: With decades of containment efforts, the prevalence of C. sinensis infection in Korea has shown a declining trend. However, well-tailored intervention assessments remain challenging, particularly when considering the potential impacts of cohort variations in raw freshwater fish consumption behavior, a major transmission route to humans, on this observed decline.

Methodology: We applied an age-period-cohort modeling approach to nationally representative C. sinensis infection prevalence data from 1981-2012 in Korea to assess age, period, and cohort effects on its secular trend and to project the age-stratified prevalence up to 2023.

Principal findings: Our analysis suggests that both cohort and period effects have substantially contributed to the declining prevalence of C. sinensis infection in Korea. Age-stratified projections up to 2023 suggest a decline in prevalence across all age groups, while those aged over 40 are anticipated to maintain prevalences above the elimination threshold of 1%.

Conclusions: Our study highlights the importance of incorporating cohort effects into intervention assessments aimed at controlling C. sinensis infection. The effectiveness of interventions remains evident in Korea despite adjusting for the cohort effect. This approach, applicable to other endemic countries, would provide valuable insights for intervention assessments and inform future public health planning to eliminate C. sinensis infection.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Animals
  • Child
  • Child, Preschool
  • Clonorchiasis* / epidemiology
  • Clonorchis sinensis*
  • Cohort Studies
  • Female
  • Humans
  • Infant
  • Male
  • Middle Aged
  • Prevalence
  • Republic of Korea / epidemiology
  • Young Adult

Grants and funding

This work was supported by the Centers for Disease Control and Prevention Safety and Healthcare Epidemiology Prevention Research Development programme (200-2016-91781 to S-mJ), and by Hanyang University College of Medicine (HY-202000000000495 to SHK). This study was also supported by the Korea Disease Control and Prevention Agency (KDCA 6331-311, 2022). The funders had no role in study design, data analysis, decision to publish, or manuscript preparation.