Clinical and epidemiological characteristics of patients hospitalized with severe influenza in the season 2012-2013
Abstract
Aim of the study: To characterize the clinical and epidemiological features of patients hospitalized with moderate to severe influenza infection at the infec-tious diseases department of a tertiary care hospital in the epidemic season 2012-2013. Material and Methods: A prospective observational study of patients hospitalized with influenza infection in the season 2012-2013 was carried out at the Infectious Diseases Department, Na Bulovce Hospital in Prague.
Influenza infection was diagnosed by real-time quantitative polymerase chain reaction (RT-qPCR) in nasopharyngeal swab or tracheal aspirate specimens. Demographic, clinical, and laboratory data were recorded along with the disease course and outcome.
Results: One hundred and ninety-nine patients, 85 females and 114 males (age median 47, range 1-87 years), were hospitalized with confirmed influenza in the epidemic season 2012-2013. Only seven of them got the influenza vaccine.
Altogether 136 patients were diagnosed with influenza type A (91 with H1N1pdm, 33 with H3N2, and 12 with an unknown subtype), 66 patients with type B, and three patients with both types A and B. One hundred and eight patients (54%) had an underlying chronic disease, most often cardiovascular or pulmonary.
The main symptoms of influenza were fever, cough, headache, myalgia, and arthralgia. Pneumonia was the most common complication: twenty-one patients suffered from primary viral pneumonia and 35 from bacterial pneumonia.
Twenty-three patients (12%) needed intensive care. Six patients died and the leading cause of death was heart failure.
Conclusion: During the epidemic influenza season 2012-2013, more patients were hospitalized than in the pandemic season 2009-2010. Also the proportions of complicated cases and case fatality ratios were fully comparable in both seasons.
The fact that most patients were not vaccinated clearly supports the recommendation to vaccinate every year both the individuals at high risk of complications.