Abstract
BACKGROUND: Human metapneumovirus (hMPV) is an emerging respiratory pathogen causing illnesses from mild upper respiratory infection to severe pneumonia, particularly in high-risk adults. Although primarily recognized in pediatrics, hMPV is increasingly reported as a cause of acute respiratory failure in adults with chronic lung disease and obesity. CASE: A 58-year-old man with morbid obesity and chronic obstructive pulmonary disease presented with acute respiratory failure and viral septic shock. Molecular testing of bronchoalveolar lavage (BioFire® FilmArray®) identified human metapneumovirus type 1 as the sole pathogen. The patient required invasive mechanical ventilation, vasopressor support, and continuous renal replacement therapy. Vancomycin was discontinued for suspected nephrotoxicity, and systemic corticosteroids were introduced. Subsequent bronchoalveolar lavage cultures grew Streptococcus pneumoniae, confirming bacterial superinfection. With supportive management, the patient gradually improved, was extubated on day 9, and was discharged home in stable condition. CONCLUSION: hMPV can trigger severe respiratory failure and multiorgan dysfunction in adults with chronic respiratory comorbidities. Early molecular diagnosis is crucial to guide management and limit unnecessary antimicrobial exposure. The absence of specific antivirals underscores the need for continued research into targeted treatments and preventive vaccines.