Focus on Hepatitis C Virus Genotype Distribution in Tunisia Prior to Elimination: a 16-Year Retrospective Study

With the introduction of direct-acting antiviral treatment (DAA), Tunisia has committed to achieving the international goal of eliminating viral hepatitis. Because the specific DAA prescribed depends on viral genotype, viral genotyping remains of great importance. The aim of the present study was to outline the trends in the distribution of HCV genotypes from 2002 to 2017 in the Tunisian general population in order to guide authorities towards the most appropriate therapeutic strategies for preventing HCV infection. A total of 2532 blood samples were collected over a 16-year period and from all regions of Tunisia. Genotyping showed that genotype 1 (subtype 1b) was the most prevalent genotype in the country (n = 2012; 79.5%), followed by genotype 2 (n = 339; 13.3%). Genotypes 3, 4 and 5 were detected in 4.8%, 2.2% and 0.1% of the country’s population, respectively. Mixed infections with different HCV genotypes were detected in 0.1% of the population (one case each of genotypes 1b + 4, 1b + 2 and 2 + 4). Interestingly, a significant increase in genotypes 2, 3 and 4 was observed over time (p = 0.03). Sixteen different subtypes were detected over the study period, most of which were subtypes of genotype 2, and some of these subtypes appeared to be new. Patients infected with genotypes 1a, 3 and 4 were significantly younger than those infected with genotypes 1b and 2 (p < 0.01). Furthermore, genotypes 1b and 2 were detected more often in women than men, while genotypes 1a and 3 were detected mostly in men (P < 0.01). Our study confirms a large predominance of genotype1/subtype1b in Tunisia and shows a significant increase in the prevalence of other genotypes over time. These findings reinforce the need for an additional HCV genotype survey to improve the design of treatment strategies in Tunisia.