Korea Disease Control and Prevention Agency (KDCA, formerly KCDC), CJD surveillance system

Key facts

• KCDC began CJD reporting in 2001; before 2010 it relied on sample monitoring at medical institutions.
• CJD became a statutory infectious disease in December 2010, after which KCDC carried out full epidemiologic investigations and genetic testing of all diagnosed patients.
• The operator is the KDCA; reports go through its Integrated System, cities and provinces do the epidemiological investigation, and a clinician-led expert committee decides the final classification.
• A KDCA-authored review describes the system as sentinel from 2001 to 2010 and total surveillance from 2011, with reporting open to any medical institution; this differs slightly from the December 2010 date in the independent analysis.
• 579 cases were reported for 2001 to 2019: 545 sporadic, 33 familial and 1 iatrogenic, with no variant CJD.
• Annual incidence rose from 0.11 per million in 2001 to 1.02 per million in 2019, peaking at 1.28 per million in 2014; the authors point to better diagnostics, more neurologists, an ageing population and the 2010 statutory change as possible reasons.
• For 2017 to 2021, 786 suspected cases were reported and 276 (35.1 percent) were classified probable; yearly probable counts were 38, 54, 53, 64 and 67, with incidence 0.7 to 1.3 per million.
• In that period 240 cases (87.0 percent) were sporadic and 36 (13.0 percent) genetic, with no iatrogenic or variant cases; 93.8 percent of patients were 50 or older.
• Diagnosis uses clinical features, EEG, MRI, CSF 14-3-3 by western blot, CSF total tau, RT-QuIC and PRNP sequencing; RT-QuIC was positive in 66.3 percent of the probable cases (lower in genetic cases).
• Autopsy is rare: the KDCA review reports eight autopsies at one hospital centre for 2017 to 2021 and says rates are low because of family refusal and limited awareness.
• A 2015 study of a separate nationwide active surveillance network found 106 of 218 requested CSF samples (48.6 percent) 14-3-3 positive between May 2010 and August 2012, with 38 of 89 fully documented patients having probable CJD (about 16.3 cases a year); the authors judged reporting under-captured cases.
• In January 2009 KCDC let sentinel institutions report suspected variant CJD straight to the KCDC director, widened the case form to cover exposure history, added blood donation exclusion criteria to the guideline, and said it would share data with the UK-centred international vCJD network.
• The KDCA review recommends keeping surveillance for unusual cases including variant CJD, special disinfection of instruments used on probable patients, and permanent blood donation deferral for classified patients.
• A search summary of KDCA portal pages gives CJD and vCJD as class 3 (24 hour report) and the 2025 guideline as treating CJD the same way, but CJD also appears in the class 4 list on the same portal; this was not confirmed on an opened page.
• KDCA publishes a CJD management guideline that is revised often (2024 and 2025 editions seen) and, per secondary reports, a 2026 guide plus a pre-surgery and pre-endoscopy infection-risk screening guide dated 7 October 2026; neither was opened.

Timeline

1. 2001CJD reporting begins under KCDC, sentinel style.
2. 2009KCDC revises the CJD guideline: direct reporting of suspected vCJD, wider case form, blood exclusion criteria.
3. 2010to 2012-08 Active surveillance network collects 218 CSF samples for 14-3-3 testing.
4. 2010CJD becomes a statutory infectious disease.
5. 2011Monitoring changes to total surveillance.
6. 2022Incidence analysis for 2001 to 2019 published in Emerging Infectious Diseases.
7. 2023KDCA publishes its 2017 to 2021 CJD status review.
8. 2026KDCA pre-procedure CJD infection-risk screening guide dated 7 October (secondary, unopened).