Influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. Patients infected with influenza can develop complications that result in hospitalization and death. In this study, it has been aimed to interpret the clinical, virologic findings and risk factors for severe illness of the patients during 2015-2016 influenza epidemic.
Materials and Methods: The hospitalised 284 patients diagnosed with Influenza like illness during 2015-2016 influenza season, were evaluated retrospectively. Nasopharynegeal swab samples were tested for 21 different virus by PCR in Public Health Laboratory.
Results: Of the 284 patients hospitalized with the diagnose of Influenza like-illness, 134 (47.2%) were male; 150 (52.8%) were female and the median age was 31.4 (0-91) years. Clinical influenza diagnose was confirmed virologically in 175 patients. Influenza virus distribution was H1N1 in 136 (78%) patients, H3N2 in 30 patients and Influenza B in 9 (5%) patients. Clinical and/or radiological findings consistent with pneumonia were present in 97 (71.3%) of H1N1 cases, 15 (50%) of H3N2 cases and 4 (44.4%) of Influenza B cases. Mortality was statistically significantly higher in elderly (≥65 years) patients (p=0.007).
Conclusion: Beside the sentinel surveillance which is conducted in the first-level health facilities, national hospital based surveillance practices will contribute both to follow-up the influenza activity and to determine the real disease burden. Collected data will play an important role in developing both disease control measures and national vaccination policies.