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Pandemic influenza A/H1N1: comparative analysis of microscopic lung histopathological findings
Roberta Marchiori1, Carla Sakuma de Oliveira Bredt, Marcos Menezes Freitas de Campos
1Hospital Universitário do Oeste do Paraná, Cascavel, PR, Brasil.
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.
