Genotype 4 hepatitis C virus-a review of a diverse genotype.

PURPOSE: Hepatitis C virus (HCV) infection remains a major health problem and one of the leading causes of chronic liver disease worldwide. The purpose of this paper was to summarize knowledge about the epidemiology of HCV genotype (GT) 4 infection, similarities and differences with other genotypes, specific problems associated with this genotype, and treatment regimens used to treat GT4-infected patients.

METHODS: We performed an accurate search for literature using the PubMed database to select high-quality reviews and original articles concerning this topic.

RESULTS: GT4 with a global prevalence of 8% takes third place, closing the global HCV podium in terms of frequency. However, there are regions where GT4 infections are dominant, such as sub-Saharan and North Africa, and the Middle East. The disease course and complications are generally similar to those of chronic hepatitis C caused by other genotypes, although the faster progression of fibrosis was demonstrated in patients with coexisting schistosomiasis. In the era of interferon-based therapy, GT4-infected patients were described as difficult to treat due to suboptimal response. A breakthrough in the treatment of HCV-infected patients, including those with GT4 infection, was the introduction of direct-acting antiviral drugs.

CONCLUSIONS: The availability of safe and effective therapy has created a real opportunity for HCV eradication in line with the goal set by the World Health Organization. An example of a country where this is happening is Egypt, where GT4 accounts for more than 90% of HCV infections. There, broad access to therapy has been effectively supported by population-based screening.