Transmission Networks of HCV Genotype 1a Enriched With Pre-existing Polymorphism Q80K Among HIV-Infected Patients With Acute Hepatitis C in Poland.

BACKGROUND

Hepatitis C virus (HCV) resistance-associated variants (RAVs) have been shown to adversely affect treatment response of direct-acting antivirals. Identifying pre-existing RAVs and transmission networks among HIV/HCV genotype 1 (G1)-infected patients from Poland will assist in shaping surveillance strategies for HCV.

METHODS

NS3 and NS5A sequences were obtained from samples of 112 direct-acting antiviral-naive G1 patients (45 G1a and 67 G1b), of which 74 were chronically infected and 38 were diagnosed with acute hepatitis C (AHC). RAVs were identified using geno2pheno, and 98 concatenated NS3/NS5A alignments were constructed to identify transmission clusters using a maximum likelihood approach.

RESULTS

G1a was notably more prevalent compared with G1b among men-having-sex-with-men (MSM) (60.0% vs. 31.3%, P = 0.004), AHC cases (46.7% vs. 25.4%, P = 0.019), and patients diagnosed with syphilis (52.2% vs. 24.5%, P = 0.009). The overall NS3/NS5A RAVs frequency was 14.3% with variants occurring more often in G1a compared with G1b (27.5% vs. 5.2%, P = 0.005), mostly for NS3 due to the high prevalence of polymorphism Q80K. NS5A RAVs were only found in 2.9% of sequences. Significant clustering was observed for 73.5% of the Polish sequences, however, more common in G1a MSM compared with G1b (50.0% vs. 25.9%, P = 0.02). The identified clusters contained sequences originating from up to 5 Polish cities, located within a mean distance of 370 km.

CONCLUSIONS

Close clustering of Polish strains suggests the presence of compartmentalized epidemics of MSM that fuel the spread of G1a variants. Particularly patients with AHC form a national transmission network, including clusters enriched with the NS3 Q80K polymorphism.