1887
Research Open Access
Like 0

Abstract

INTRODUCTION

Enteroviruses cause symptoms ranging from mild skin manifestations to severe neurological diseases, such as polio. Despite global eradication efforts, poliovirus was detected via environmental surveillance in multiple European countries in 2024 and 2025.

AIM

We aimed to assess the epidemiology of enteroviruses in Denmark, using national laboratory surveillance and hospital discharge registries, and to determine the accuracy of enterovirus registration.

METHODS

Hospital admission data from 1 January 2010 to 31 December 2023 were linked to laboratory surveillance enterovirus data to identify and categorise admissions with an enterovirus-specific ICD-10 code and/or enterovirus-positive test. The accuracy of diagnosis coding and positive enterovirus tests was assessed against an estimated ‘true population’ using a capture‒recapture analysis.

RESULTS

Among patients with an ICD-10 enterovirus code and a positive enterovirus test (n = 1,186), 69% had a central nervous system diagnosis. Patients with ICD-10 enterovirus codes only (n = 3,434) were younger and primarily had hand, foot and mouth disease. Patients positive for enterovirus without an enterovirus diagnosis (n = 3,263) frequently exhibited respiratory symptoms. The combined accuracy of ICD-10 codes and enterovirus tests was 46.3% (95% confidence interval (CI): 44.3–48.4) against an estimated ‘true population’ of 28,193 (95% CI: 26,929–29,457) enterovirus infections.

CONCLUSION: It is important to combine laboratory data and ICD-10 codes to gain comprehensive understanding of the enterovirus epidemiology and identify areas for improvement in enterovirus surveillance. Despite exceptional registries, the Danish system may still overlook early cases of emerging or severe enterovirus infections because of limited clinical awareness of these infections and the challenges associated with voluntary test registrations.

Loading

Article metrics loading...

/content/10.2807/1560-7917.ES.2026.31.10.2500477
2026-03-12
2026-04-19
/content/10.2807/1560-7917.ES.2026.31.10.2500477
Loading
Loading full text...

Full text loading...

/deliver/fulltext/eurosurveillance/31/10/eurosurv-31-10-4.html?itemId=/content/10.2807/1560-7917.ES.2026.31.10.2500477&mimeType=html&fmt=ahah

References

  1. Böttcher S, Kreibich J, Wilton T, Saliba V, Blomqvist S, Al-Hello H, et al. Detection of circulating vaccine-derived poliovirus type 2 (cVDPV2) in wastewater samples: a wake-up call, Finland, Germany, Poland, Spain, the United Kingdom, 2024. Euro Surveill. 2025;30(3):2500037.  https://doi.org/10.2807/1560-7917.ES.2025.30.3.2500037  PMID: 39850005 
  2. European Centre for Disease Prevention and Control (ECDC). Detection of wild poliovirus in wastewater in Germany: risk and recommendations. Stockholm: ECDC; 2025. Available from: https://www.ecdc.europa.eu/en/news-events/detection-wild-poliovirus-wastewater-germany-risk-and-recommendations
  3. Taravilla CN, Pérez-Sebastián I, Salido AG, Serrano CV, Extremera VC, Rodríguez AD, et al. Enterovirus A71 infection and neurologic disease, Madrid, Spain, 2016. Emerg Infect Dis. 2019;25(1):25-32.  https://doi.org/10.3201/eid2501.181089  PMID: 30560775 
  4. Wu H, Xue M, Wu C, Lu Q, Ding Z, Wang X, et al. Trend of hand, foot, and mouth disease from 2010 to 2021 and estimation of the reduction in enterovirus 71 infection after vaccine use in Zhejiang Province, China. PLoS One. 2022;17(9):e0274421.  https://doi.org/10.1371/journal.pone.0274421  PMID: 36126038 
  5. Foli-Andersen PJ, Munkholm A, Rønde G, Børresen ML, Nielsen JEK, Midgley S, et al. Acute flaccid rhombencephalomyelitis with radiculitis in a child with an enterovirus A71 infection seen for the first time in Denmark: a case report. J Med Case Rep. 2022;16(1):32.  https://doi.org/10.1186/s13256-021-03246-x  PMID: 35073972 
  6. Cassidy H, Poelman R, Knoester M, Van Leer-Buter CC, Niesters HGM. Enterovirus D68 - the new polio? Front Microbiol. 2018;9:2677.  https://doi.org/10.3389/fmicb.2018.02677  PMID: 30483226 
  7. Lang M, Mirand A, Savy N, Henquell C, Maridet S, Perignon R, et al. Acute flaccid paralysis following enterovirus D68 associated pneumonia, France, 2014. Euro Surveill. 2014;19(44):20952.  https://doi.org/10.2807/1560-7917.ES2014.19.44.20952  PMID: 25394254 
  8. Holm-Hansen CC, Midgley SE, Fischer TK. Global emergence of enterovirus D68: a systematic review. Lancet Infect Dis. 2016;16(5):e64-75.  https://doi.org/10.1016/S1473-3099(15)00543-5  PMID: 26929196 
  9. Pfeiffer HC, Bragstad K, Skram MK, Dahl H, Knudsen PK, Chawla MS, et al. Two cases of acute severe flaccid myelitis associated with enterovirus D68 infection in children, Norway, autumn 2014. Euro Surveill. 2015;20(10):21062.  https://doi.org/10.2807/1560-7917.ES2015.20.10.21062  PMID: 25788251 
  10. Singanayagam A, Moore C, Froude S, Celma C, Stowe J, Hani E, et al. Increased reports of severe myocarditis associated with enterovirus infection in neonates, United Kingdom, 27 June 2022 to 26 April 2023. Euro Surveill. 2023;28(39):2300313.  https://doi.org/10.2807/1560-7917.ES.2023.28.39.2300313  PMID: 37768558 
  11. Melicosta ME, Dean J, Hagen K, Oppenheimer K, Porter C, Rybczynski S, et al. Acute flaccid myelitis: Rehabilitation challenges and outcomes in a pediatric cohort. J Pediatr Rehabil Med. 2019;12(3):245-53.  https://doi.org/10.3233/PRM-180549  PMID: 31476175 
  12. Jartti M, Flodström-Tullberg M, Hankaniemi MM. Enteroviruses: epidemic potential, challenges and opportunities with vaccines. J Biomed Sci. 2024;31(1):73.  https://doi.org/10.1186/s12929-024-01058-x  PMID: 39010093 
  13. Fischer TK, Johannesen CK, Benschop KSM, Berginc N, Saxentoff EV, Huseynov S, et al. Poliovirus circulation in the WHO European region, 2015-2022: a review of data from WHO’s three core poliovirus surveillance systems. Lancet Reg Health Eur. 2024;47:101104.  https://doi.org/10.1016/j.lanepe.2024.101104  PMID: 39498118 
  14. Harvala H, Benschop KSM, Berginc N, Midgley S, Wolthers K, Simmonds P, et al. European Non-Polio Enterovirus Network: introduction of hospital-based surveillance network to understand the true disease burden of non-polio enterovirus and parechovirus infections in Europe. Microorganisms. 2021;9(9):1827.  https://doi.org/10.3390/microorganisms9091827  PMID: 34576722 
  15. Condell O, Midgley S, Christiansen CB, Chen M, Chen Nielsen X, Ellermann-Eriksen S, et al. Evaluation of the enterovirus laboratory surveillance system in Denmark, 2010 to 2013. Euro Surveill. 2016;21(18).  https://doi.org/10.2807/1560-7917.ES.2016.21.18.30218  PMID: 27173593 
  16. Johannesen CK, Egeskov-Cavling AM, Jepsen MPG, Lange T, Krause TG, Nygaard U, et al. Changing rates but persisting seasons: patterns of enterovirus infections in hospitalizations and outpatient visits in Denmark 2015-2022. Front Virol. 2024;4:1346352.  https://doi.org/10.3389/fviro.2024.1346352 
  17. Schmidt M, Pedersen L, Sørensen HT. The Danish Civil Registration System as a tool in epidemiology. Eur J Epidemiol. 2014;29(8):541-9.  https://doi.org/10.1007/s10654-014-9930-3  PMID: 24965263 
  18. Schmidt M, Schmidt SAJ, Sandegaard JL, Ehrenstein V, Pedersen L, Sørensen HT. The Danish National Patient Registry: a review of content, data quality, and research potential. Clin Epidemiol. 2015;7:449-90.  https://doi.org/10.2147/CLEP.S91125  PMID: 26604824 
  19. Lynge E, Sandegaard JL, Rebolj M. The Danish National Patient Register. Scand J Public Health. 2011;39(7 Suppl);30-3.  https://doi.org/10.1177/1403494811401482  PMID: 21775347 
  20. Helweg-Larsen K. The Danish Register of Causes of Death. Scand J Public Health. 2011;39(7 Suppl);26-9.  https://doi.org/10.1177/1403494811399958  PMID: 21775346 
  21. R Foundation for Statistical Computing. R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing; 2023. Available from: www.R-project.org
  22. RStudio Team. RStudio: Integrated development for R. Boston: Posit software; 2020. Available from: www.posit.co
  23. Kamau E, Nguyen D, Celma C, Blomqvist S, Horby P, Simmonds P, et al. Seroprevalence and virologic surveillance of enterovirus 71 and coxsackievirus A6, United Kingdom, 2006-2017. Emerg Infect Dis. 2021;27(9):2261-8.  https://doi.org/10.3201/eid2709.204915  PMID: 34423767 
  24. Egeskov-Cavling AM, Johannesen CK, Lindegaard B, Fischer TK, PROMISE investigators. Underreporting and misclassification of RSV-coded hospitalization among adults in Denmark between 2015/16 to 2017/18. J Infect Dis. 2024;229(Supplement 1):S78-83.  https://doi.org/10.1093/infdis/jiad415  PMID: 37747825 
  25. Jørgensen LK, Dalgaard LS, Østergaard LJ, Andersen NS, Nørgaard M, Mogensen TH. Validity of the coding for herpes simplex encephalitis in the Danish National Patient Registry. Clin Epidemiol. 2016;8:133-40.  https://doi.org/10.2147/CLEP.S104379  PMID: 27330328 
/content/10.2807/1560-7917.ES.2026.31.10.2500477
Loading

Data & Media loading...

Supplementary data

Submit comment
Close
Comment moderation successfully completed
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error