Enterovirus respiratory infection in adults: an overlooked clinical burden emerging in the post-pandemic era.

Enterovirus (EV) is increasingly identified as a cause of acute respiratory infections in adults, yet its clinical burden in real-world settings remains poorly characterized. Individuals with underlying chronic respiratory conditions, such as asthma or chronic obstructive pulmonary disease, are at heightened risk of severe respiratory compromise from EV infection, as they are from many other respiratory pathogens. Following an increase in EV circulation in our healthcare district in recent years, as reported in other countries, we performed a retrospective analysis of all adults (≥18 years) including only acute respiratory EV infection documented by multiplex RT-PCR of nasopharyngeal swabs between January and December 2024. Seventy patients were included (mean age 68.5 ± 19.2 years, balanced sex distribution) with a high prevalence of comorbidities, particularly cardiovascular disease (37%) and chronic respiratory disease (34%). The clinical presentation was dominated by cough (74%) and dyspnea (70%), whereas fever was less common. At presentation, 41% (n=29) met criteria for acute respiratory failure, defined as a partial pressure of oxygen <60 mmHg on arterial blood gas. Chest radiography was abnormal in most cases (74%), showing predominantly interstitial markings (51%), followed by consolidations (16%) and mixed patterns (7%). Inflammatory markers were frequently elevated, with C-reactive Protein >0.5 mg/dL in 93.7% and leukocytosis in 44.3%. Forty patients (57%) required hospital admission, 35 (50%) needed oxygen or ventilatory support (predominantly low-flow oxygen), and seven patients (10%) required escalation to advanced support (high-flow oxygen in four cases, non-invasive ventilation in two, and invasive mechanical ventilation in one). Two patients (2.8%) were admitted to the Intensive Care Unit, and 30-day mortality was 2.8% (n=2). In our cohort, patients with COPD (n = 14) had the most severe course (respiratory failure 57%, oxygen requirement 64%, hospitalization 71%, 1 IMV, 1 death), whereas those with asthma (n = 7) had a comparatively milder clinical course (respiratory failure 43%, no ventilatory support, no deaths). Overall, in our real-world scenario, EV infection was associated with frequent gas-exchange impairment, radiographic abnormalities, and clinically meaningful resource utilization in adults, particularly among those with chronic respiratory disease.