Volume 32, Number 11—November 2026
Research
Invasive Enterovirus and Parechovirus Infections in Adults, Alberta, Canada, 2023–2025
, Hong Yuan Zhou, Nathan Zelyas, Kanti Pabbaraju, Anita Wong, Kara Gill, Tarah Lynch, Graham Tipples, Nabeela Nathoo, Dima Kabbani, and Adil Adatia
Table 3
Population-estimated incidence rates and rate comparisons for invasive enterovirus and parechovirus infections in adults, Alberta, Canada, 2023–2025*
| Measurements† | Incidence/100,000 PY (95% CI)‡ | IRR (95% CI)‡ | p value |
|---|---|---|---|
| Overall incidence rates | |||
| Invasive enterovirus and parechovirus | 0.37 (0.27–0.51) | NA | |
| Enterovirus only |
0.36 (0.26–0.50) |
NA |
|
| Incidence rates according to age group, y | |||
| 17–29 | 0.72 (0.41–1.16) | NA | |
| 30–49 | 0.51 (0.31–0.78) | NA | |
| 50–64 | 0.05 (0.00–0.25) | NA | |
| >65 |
0.10 (0.01–0.36) |
NA |
|
| Age-group comparisons, y§ | |||
| 17–29 vs. 30–49 | NA | 1.42 (0.69–2.89) | 0.30 |
| <50 vs. >50 |
NA |
8.21 (2.59–41.65) |
<0.001 |
| Annual incidence rates¶ | |||
| May–December 2023 | 0.56 (0.31–0.95) | NA | |
| 2024 | 0.20 (0.09–0.40) | NA | |
| 2025 |
0.42 (0.25–0.68) |
NA |
|
| Annual comparison | |||
| 2025 vs. 2024 |
NA |
2.07 (0.85–5.54) |
0.11 |
| Sex-stratified incidence rates# | |||
| F | 0.42 (0.26–0.64) | NA | |
| M |
0.33 (0.19–0.52) |
NA |
|
| Sex comparison | |||
| F vs. M |
NA |
1.30 (0.66–2.61) |
0.43 |
| Critical or fatal outcome incidence rate** | |||
| ICU/CCU admission, ECMO support, or death attributed to invasive virus infection | 0.02 (0.00–0.07) | NA | |
*CCU, cardiac care unit; ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit; IRR, incidence rate ratio; NA, not applicable; PY, person-years. †Unless otherwise indicated, rates were calculated for the entire study (May 2023–December 2025) and represent invasive enterovirus and parechovirus infections. Rates were calculated by using population estimates obtained from the Alberta Population Table, Government of Alberta, Office of Statistics and Information (https://goa-osi-dashboards.azurewebsites.net/Reports). ‡Exact Poisson 95% CI was calculated. §The overall comparison of incidence rates across all 4 age groups was statistically significant (exact conditional test of homogeneity; p<0.001). ¶Because the surveillance period in this study began in May 2023, the annualized 2023 incidence disproportionately represents months of expected seasonal enterovirus circulation and should not be directly compared with complete calendar years. #Reported in the patient’s charts at the time PCR was used to detect enterovirus and parechovirus. **Includes all patients infected with invasive enterovirus or parechovirus (n = 39).