Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 39 2 2010 06 15 39 44 M Hajia AA Amirzargar H Khedmat N Shahrokhi M Farzanehkhah SM Ghorishi S Biglari AR Salehinodeh A Sarafnejad 2015 10 03 Background: Successful treatment to eliminate HCV RNA depends on the identified genotype. In the present study, we com­pared the frequency of different HCV genotypes, during four years study (2004 till 2008).  Methods: Sera specimens were received from 16 provinces of Iran. We used High Pure Viral Nucleic Acid Purification kit for extraction and samples were tested with improved form of RT-PCR technique. HCV genotypes were determined using Am­plisense PCR kit and Amplicor HCV Monitoring Version 2 test utilized a reverse transcription (RT)-PCR approach to quan­titative HCV RNA. Two hundreds six HCV positive specimens were entered to the study out of 389 tested samples. Results: Type 3a was the most frequent type (46.6%), followed by type 1 (including 1a and 1b with 25.73% and 17.47% for each respectively) with 43.2%. Looking through collected results of the four years study confirmed the rate of HCV infec­tion in those single genotypes 1b, 3a were slightly increased from 12.22% and 38.88% in the first year to 18.66 and 46.51% in the fourth year of the study period. Conclusion: The analyzed data proved that some patients were infected with two different types.  High viral load was also more correlated to genotype 1 than other types. https://ijph.tums.ac.ir/index.php/ijph/article/view/3115 https://ijph.tums.ac.ir/index.php/ijph/article/download/3115/2914