A Case of Metapneumovirus Pneumonia-Related Acute Respiratory Distress Syndrome in a Young Adult Patient

Human metapneumovirus (hMPV) infections commonly present as mild upper respiratory tract infections in healthy adults, although severe respiratory complications have been observed, particularly in elderly and immunocompromised patients. We report a case in whom pneumonia caused by hMPV progressed to acute respiratory distress syndrome (ARDS) in a healthy adult without underlying diseases. A 31-year-old female presented with fever and dyspnea, prompting transfer to our hospital for mechanical ventilation 3 days after symptom onset. Auscultation revealed coarse breath sounds and crackles in both lung fields, and chest X-ray showed non-specific infiltrative nodules with poorly defined borders throughout both lungs. ARDS caused by community-acquired pneumonia was diagnosed. hMPV was identified via rapid testing of respiratory samples for genes that encode pneumonia pathogens and drug resistance markers; we employed reverse transcription polymerase chain reactions to these ends. Six days later, the patient was weaned off the mechanical ventilator, and discharged from the hospital in good clinical condition.