RESUMEN
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]. 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. 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. 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