Abstract Background Human metapneumovirus (hMPV) is an increasingly recognised acute respiratory pathogen in immunocompromised populations, yet its burden among patients with haematological malignancy remains poorly characterized. Unlike influenza or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), hMPV lacks both targeted treatment and vaccination options, contributing to diagnostic neglect and clinical underestimation. Methods We conducted a multicentre, retrospective cohort study within the EPICOVIDEHA/EPIRESEHA registry, analysing patients with haematological malignancy diagnosed with hMPV from January 2023 to December 2024. Clinical, epidemiological, and outcome data were collected and compared with matched cohorts of patients with influenza and SARS-CoV-2 infections. Mortality predictors were assessed via Cox regression. Results The study included 130 patients with hMPV. Median age was 58.5 years; 57% were male. Plasma cell neoplasms (25%), lymphoma (23%), and AML (20%) were the most common haematological malignancies. Hospitalisation occurred in 64%, ICU admission in 19%, and 30-day mortality was 8%. Most cases (73%) received supportive care only. Secondary infections were common (24%). Chronic renal disease significantly increased mortality risk (20.9HR 11.05, p=0.014). Compared to influenza and SARS-CoV-2, hMPV patients had comparable severity and outcomes, with ICU admission rates of 18.5% versus 25.9% for influenza (p=0.316) and 20.9% versus 4.7% for SARS-CoV-2 (p=0.006), and 30-day mortality of 5.6% versus 11.1% for influenza (p=0.489) and 7.0% versus 2.3% for SARS-CoV-2 (p=0.277), yet received fewer targeted interventions. Conclusions hMPV causes clinically significant disease in patients with haematological malignancy, often necessitating hospital and ICU care, and leading to mortality. In the absence of specific treatments or vaccines, this virus remains an under-recognized pathogen in patients with haematological malignancy. Enhanced clinical awareness and investment in diagnostics, prevention, and therapeutics are needed.
Salmanton-García et al. (Fri,) studied this question.