Relative Frequency of Seasonal Influenza A and B in Khuzestan Province by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) During 2009-2010

Background: influenza a and b viruses are the major causative agents of human respiratory infections, and these viruses are responsible for considerable mortality and morbidity around the world.objectives: the objective of this study was to determine the frequency of influenza among suspected patients with influenza-like syndrome by rt- pcr assay in khuzestan province of iran during 2009-2010.patients and methods: nasopharyngeal swabs were collected from 655 suspected patients with influenza-like syndrome in khuzestan province iran from march 2009 to february 2010. clinical samples were taken within the 48 hours of initial symptoms, and were stored at -70 ? c. the patients were between 1 month and 85 years old. initially all samples were tested for influenza a and b viruses. subsequently, for those samples with positive results for influenza a virus, influenza a/h3n2, and a/h1n1 tests were performed. the total assays were performed using rt-pcr.result: of 655 samples, 69 (10.53%) had positive results for human influenza a virus, and 5 (0.7%) samples had positive results for influenza b. of those 69 samples with positive results for influenza a viruses, 45 (6.8%) were h3n2, and 24 (3.6%) were h1n1 subtypes. in this study most cases with positive results were less than 20 years. the sample positive included 49% males and 51% females. the peak seasonal influenza was between october and december 2009.conclusions: this finding showed that the predominant subtype of influenza virus among patients is a/h3n2, followed by a/h1n1 and b in khuzestan province during the 2009-2010.