P0051 Paper Poster Session Novel diagnostics for viral hepatitis

The molecular genetic variety of the hepatitis C virus in

Elena Gasich*1, Vladimir Eremin2

1The Republican Research&practical Center for Epidemiologyµbiology, , Belarus

2Republican Research & Practical Centre for Epidemiology & Microbiology, Minsk, Belarus

Background: Hepatitis C virus (HCV) infection is one of the major health issues in Belarus. Despite the fact that over the last 5 years the number of acute cases has decreased from

1,82/100000 in 2002 to 0,99/100000 in 2014, there is a steady upward trend to chronic form of HCV infection (27.81/100,000 in 2014 versus 15,16/100000 cases in 2002). Since 2008 in Belarus carried out permanent molecular epidemiological control of HCV infection in different risk groups for prevention of viral spread. Here we report the HCV subtypes distribution in Belarus during last 15 years.

Material/methods: The sequences of HCV core/E1 and NS5 gene regions were collected in 2000-2015 from 887 HCV-infected individuals from all six geographical . HCV subtypes were determined by phylogenetic analysis with Maximum Likelihood estimation using HCV subtype reference sequences.

Results: Genotyping of 887 HCV core/E1 and NS5 sequences reveals presence of four HCV major types with prevalence of HCV type 1 (67,0%, n=594) followed by HCV type 3 (27,7%, n=246), HCV types 2 and 4 accounts for 5,3% of all cases. HCV type 1 is present in 1a and 1b subtypes with occurrence rates 7,1% и 59,9% respectively. Phylogenetic analyses indicate that HCV type 3 is present as only 3a subtype, HCV type 2 is represented by three subtypes: 2а (n=17, 1,9%), 2с (n=7, 0,8%) and 2k (n=18, 2,0%). Five cases of HCV type 4 were found - four cases with 4d (0,5%) and 1 case (0,1%) with 4a subtypes. Regional distribution of hepatitis C showed 1b subtype prevalence in all geographic regions. In the majority of HCV cases were related to subtypes 1b and 3a (56,9% and 33,3% respectively), additionally were found 1a (3,9% ) and 2k (5,9%) subtypes. In the also prevails the 1b (63,0%) and 3а (31,1%) subtypes, followed by 2а (3,0%), 2с (1,5%), 2k (0,7%) and 4d (0,7%) subtypes. - 1b (52,8%) and 3а (37,7%) followed by 1a (1,9%), 2а (3,8%) and 2k (3,8%) subtypes. In we are not found significant prevalence of any of single HCV subtype - the 1a subtypes was found in 36,8% cases, 1b and 3а subtypes – in 32,4% and 30,9% cases respectively. In region the 1b subtype of HCV observed in 57,0% cases, 3а – in 29,1%, 1а – 7,6%, 2а – 2,5% and 2с – in 3,8%. Conclusions: Phylogenetic analysis showed that ~95% of all patients with hepatitis C infection in Belarus are infected with the 1b and 3a subtypes of HCV. Only ~5% cases accounted for minor subtypes such as 1a, 2a, 2c, 2k, 4a and 4d.