فراوانی ویروس آنفلوآنزای A/H1N1 در نمونه های بیماران با علایم آنفلوآنزا در شمال ایران

Background and purpose: Influenza is a respiratory infection that annually affects 5-15% of the global population. Influenza A/H1N1 is the most virulent human pathogens that results in a more severe disease and was first reported in 2009. The aim of this study was to investigate the epidemiology of influenza A/H1N1 in patients referring to several hospitals in North of Iran during 2009-2011. Materials and methods: This descriptive cross-sectional study was done on patients with symptoms of influenza using Real-Time PCR analysis. Results: The patients included 572 (41.97%) male and 791 (58.03%) female. The prevalence of influenza A/H1N1 was seen more in patients aged 21-30 (25%) years. In this study, 205 patients (15.4%) were diagnosed with influenza A/H1N1 including 94 (54.85%) male and 111 (54.15%) female. Influenza A/H1N1-associated death was seen in five patients (2.44%). Conclusion: Influenza A viruses are constantly evolving by mutation or by reassortment. The influenza virus evolves rapidly, and new strains quickly replace the older once, therefore, new vaccines should be developed for immunization against new strains of influenza.