Severe respiratory failure associated with influenza B virus infection

A 72-year-old man who had been diagnosed with type B influenza infection and high fever 4 days previously was admitted to our hospital. He presented with severe respiratory insufficiency; chest computed tomography (CT) revealed extensive ground-glass opacity in lung fields on both sides. Although peramivir and antibiotics were administered, reticular shadows on chest CT worsened and respiratory insufficiency deteriorated. The patient fulfilled the criteria for severe acute respiratory distress syndrome. Despite multimodal therapy, including noninvasive positive pressure ventilation, polymyxin B-immobilized fiber column hemoperfusion, and methylprednisolone infusion, his general condition gradually deteriorated. He died of respiratory failure on day 129. Pathology findings of the lungs during autopsy showed diffuse alveolar damage. To our knowledge, this is the first report of severe respiratory failure after type B influenza infection. Clinicians should be aware of the potential for fatal respiratory failure in cases of type B as well as type A influenza infections.