Influenza pandêmica A/H1N1: análise comparativa de altera？？es histopatológicas pulmonares

objective: to analyze the histopathological lung findings of four fatal cases of the 2009 h1n1 influenza pandemic and their correlation with clinical and epidemiological characteristics. methods: descriptive data from medical records of four patients who died in the intensive care unit of a university hospital in 2009. nasopharyngeal aspirate specimens were collected from the patients and were analyzed by real-time polymerase chain reaction. lung biopsy was performed post mortem; a score of intensity for pathological changes was applied. results: three patients had positive real-time polymerase chain reaction (although all of them had a clinical diagnose of influenza h1n1). the main histopathological changes were: exudative diffuse alveolar damage with atelectasis; varying degrees of alveolar hemorrhage and edema, necrosis and sloughing of the respiratory epithelium in several bronchioli; and thrombus formation. one of the patients (the pregnant one) presented histopathological findings of cytomegalic inclusion. conclusion: the pulmonary histopathological findings in patients with fatal 2009 h1n1 influenza pandemic disclosed intense alveolar damage and hemorrhage and severe bronchiolitis. a co-infection with cytomegalovirus was described in the pregnant patient.