Alberta surveillance identifies 39 adults with invasive enterovirus or parechovirus infections

Researchers conducted retrospective, population-based laboratory surveillance of adult enterovirus and parechovirus infections in Alberta, Canada, during May 2023–December 2025. Invasive infection was defined by viral nucleic acid detection in blood, cerebrospinal fluid, joint fluid, or sterile-site tissue. Chart reviews assessed clinical manifestations, immunosuppression, critical care requirements, and survival.

Of 15,621 samples tested, 162 (1.0%) were positive; 51 positive samples from 39 patients met the invasive infection definition. Cerebrospinal fluid, blood, and cardiac tissue were the most frequent positive specimen types. Invasive infection incidence was 0.37 cases per 100,000 person-years. Rates were higher among patients younger than 50 than among those older than 50 (incidence rate ratio 8.2; p<0.001). The apparent increase in 2025 versus 2024 was not statistically significant (incidence rate ratio 2.1; p=0.11).

Severe disseminated enterovirus infection occurred in two patients receiving ocrelizumab. These cases warrant clinical attention but do not, alone, establish causality or quantify treatment-associated risk. The retrospective, laboratory-based design captures detected infections, and event numbers were small. The supplied text ends before the treatment-specific risk analysis and does not provide complete outcome results. Emerging Infectious Diseases labels the article an early release subject to revision.