In the present study, the prevalence of HBV and HCV in the Guilan site of the PERSIAN cohort were reported. We found the prevalence of 0.2 and 0.1 for HBV and HCV, respectively. Moreover, rural participants were significantly more HBV positive, while male individuals were significantly more HCV positive. Finally, HBV positive patients had significantly lower platelet count, RDWCV, cholesterol, LDL, and LDL: HDL ratio and HCV positive patients had significantly higher MCH, MCHC, AST, ALT and HDL, and significant lower LDL and LDL: HDL ratio compared to related negative individuals.
The prevalence of HBV and HCV is very different worldwide, which is related to geographical region and demographic factors. In 2015, it has been reported that HBV seroprevalence was 8.83% (0.48 - 22.38) in African region, 0.81% (0.20 - 13.55) in Americas region, 3.01% (0.67 - 14.77) in Eastern Mediterranean region, 2.06% (0.01 - 10.32) in European region, 1.90% (0.82 - 6.42) in South East Asian region, 5.26% (0.37 - 22.70) in Western Pacific region . Also, there is much diversity in HBV prevalence between different states/provinces of each country. Since 2006 when the national vaccination program for peoples who born after 1993 were started and continued, an obvious decrease in the HBV prevalence was seen . Therefore, Iran is classified as low to intermediate prevalence areas . Although our detected rate of HBV infection is too lower than reported pooled HBV prevalence in Iran among the general population (2.2%) in 2016 , it is approximately similar to our previous report about volunteer blood donors as 0.45 -0.48%  and to reported rates from Karaj as 0.4% , Kermanshah as 0.7%  and Kurdistan as 0.8% . Also, our reported HBV infection rate is lower than those reported from Birjand as 1.6% , Tehran, Golestan, and Hormozgan as 2.6% , and Nahavand as 2.3% . In addition, some population sub-groups are more likely susceptible to have HBV. For instance, in our province, 71.3% of hemophiliacs , and 0.38 - 3.8 % of hemodialysis patients [36-38] were HBV positive. We found that men are more HBV positive than women (16 vs. 9 cases), which is similar to previous reports from Iran about a higher prevalence of HBV infection in men [39,22].
The pooled HCV prevalence of 0.3%, 6.2%, and 32.1% was reported for general, intermediate- and high-risk Iranian populations, respectively . Again, diversities between different cities/provinces and subgroups are seen. It has been reported that all healthy adults of Isfahan and Mashhad, blood donors of Tehran, Ardabil, and Ahvaz, infertile male of Tehran, and male blood donors of Tabriz were HCV negative . Our detected HCV prevalence (0.1%) is lower than the pooled HCV prevalence of the general Iranian population as 0.3%  and is differed from the previous report from Rasht as 0.03% and Guilan as 0.32% . Also, our detected HCV prevalence is lower than other reported prevalence from Northern provinces of Iran. For instance, HCV prevalence was 0.48% in Babol, and 0.18 – 1% in Golestan. However, Zamani et al. reported similar HCV prevalence as 0.08% in the general population of Mazandaran province. Higher male HCV positivity, as seen in our study, was also reported previously from Kerman province, Zahedan, and Kavar. However, in opposite to our study, Ghadir et al. reported that females were more HCV positive compared to males in the general population of Golestan [41,42]. The finding of one woman who her daughter also was HCV positive and both had the same HCV genotype highlighted the precise role of interfamilial HCV transmission and confirmed the significant role of close relatives, which reported previously .
Although we detected no significant associations between demographic variables and prevalence of HBV and HCV, it seems that different demographic features of the population in different regions are the most important reasons for these differences in HBV and HCV prevalence. Base on Baig's study, the male to female ratio of HBV increased during the reproductive years. There may be an influence of estrogen in the protection and defense of hepatic cells against the development of chronic liver disease . In Zeng et al. study married people had the highest prevalence of HBsAg , on the other hand in Ataei et al. study in Isfahan province no statistical difference observed in terms of marital status, but males (OR= 3.79) had a higher prevalence of HBV than women .
Regarding biochemical analysis, we found some significant differences. Among them, a decrease of LDL and subsequently LDL: HDL ratio in both HBV and HCV positive patients compared to negative ones are interesting. These are in line with those reported recently as significant hypolipidemia in HBV  and HCV  patients. Lower platelet count in HBV positive, as we found in this study, also reported previously . It can be said that both HBV and HCV influenced the liver tissue, and the changes in biochemical and hematological parameters can be related to these changes in the hepatic functions.