The Emerging Landscape of Respiratory Viral Infections in Immunocompromised Children

Respiratory viral infections (RVIs) have been described traditionally as clinically important infectious complications in pediatric patients with immunosuppression, particularly in those with malignancies (hematological or solid) and recipients of hematopoietic cell or solid organ transplantation. Specifically, advances in the field of cancer therapy and novel immune-based pharmaceuticals have significantly expanded the population of children with prolonged and complex immunosuppression, whereas the widespread use and availability of molecular diagnostics have increased the detection of respiratory viruses. Additionally, these developments have improved the etiologic identification of RVIs, while introducing important challenges in clinical interpretation, mainly in differentiating incidental viral identification from clinically significant diseases. Furthermore, RVIs in immunocompromised children are characterized by heterogeneous and diverse clinical manifestations, with a range from mild upper respiratory tract involvement to severe lower respiratory tract disease, which can lead to substantial morbidity and mortality. Diagnostic strategies in this field are primarily based on nucleic acid amplification tests, requiring careful interpretation because of the possible prolonged viral shedding, co-detection, and overlapping infectious syndromes. Beyond direct clinical consequences, viral detection has an impact on infection control measures, antimicrobial stewardship decisions, and the timing of therapies. In this literature review, we offer an overview of current evidence on the epidemiology, clinical manifestations, diagnostic approaches, and management of RVIs in immunocompromised pediatric populations, underscoring the unmet need for structured, risk-adapted integration of virologic data into pediatric oncology care.