Artikel
Pneumonia in Patients with Influenza
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Veröffentlicht: | 3. Juni 2014 |
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Gliederung
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Objectives: Influenza virus attaches to and replicates in epithelial cells of the respiratory tract. Viral replication combined with the immune response to infection lead to destruction and loss of cells lining. Secondary bacterial pneumonia often occurs during influenza. The reasons why infections with influenza virus may lead to pneumonia are not understood. Several hypotheses have been proposed and disproved over the years, including one in which reduced numbers of lymphocytes allow increased susceptibility to superinfection.
Methods: We retrospectively investigated patients with influenza and pneumonia who have been admitted to Department for Infectious Diseases, General Hospital Uzice, between 2009-2011. Demographic data, information about the clinical course and evaluation of disease were obtained from hospital records. Clinical diagnosis was confirmed by isolation of Influenza virus from nasopharyngeal secretions and Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae from sputum.
Results: The total of 405 patients was treated with influenza. Bacterial pneumonia were diagnosed in 119 (29.4%) of them (64 male, 55 female). Streptococcus pneumoniae was isolated in 56 (47.1%), Staphylococcus aureus in 34 (28.9%), Haemophilus influenzae in 29 (24.4%) patients. Mean age at onset was 49.4+/-12.1 (range: 18-89). Of all patients with influenza and bacterial pneumonia co-infection, 22 (18.5%) were admitted to intensive care unit. Median hospitalization was 12 days. The case fatality was 7 (5.9%) patients (72.7% older then 65). Chronic illness, like diabetes mellitus, chronic cardiovascular, pulmonary, hematological or liver diseases and alcoholism were notified in 74 (62.2%) patients with influenza and bacterial pneumonia co-infection.
Conclusion: The most common bacterium causing pneumonia associated with influenza is Streptococcus pneumoniae. These diseases are more common in male sex and patients with chronic diseases and significantly more frequently occurs in patients of older age.