Novel H1N1 Influenza A Viral Infection Complicated by Alveolar Hemorrhage

Abstract

We report a complication of the novel H1N1 influenza A viral infection not yet described during this 2007–2009 pandemic. Pulmonary hemorrhage is a known complication of influenza pneumonia, including well documented reports from previous pandemics. A 57-year-old African American female presented with fevers, progressive shortness of breath, and cough. After being admitted with an initial diagnosis of myocardial infarction, hemoptysis developed. Nasopharyngeal swabs rapid testing was negative for influenza A and B antigen, but a polymerase chain reaction test for influenza A type H1N1 was positive. A fiberoptic bronchoscopy for ongoing hemoptysis demonstrated diffuse erythema and bleeding, and bronchoalveolar lavage was consistent with alveolar hemorrhage. Progressive hypoxemic respiratory failure ensued, eventually leading to her demise. Our case highlights one of the more feared complications that may have been more common in prior outbreaks, such as the 1918 “Spanish Flu.” Autopsy studies from the 1918 influenza pandemic found severe tracheobronchitis (oftentimes hemorrhagic), septal edema, necrotizing bronchiolitis, alveolitis, and extensive hemorrhage, as opposed to the more benign laryngitis and tracheobronchitis that is commonplace in other influenza infections. Similar pathology appearances, including pulmonary hemorrhage, have also been described in H5N1 outbreaks in China and Thailand. It is crucial for pandemic preparedness planning that additional careful and complete autopsy study of this present pandemic influenza infection be performed and reported to answer questions regarding the natural history, pathology, and pathogenesis of this novel H1N1 influenza.