High prevalence of hepatitis C virus subtypes 4c and 4d in Malaga (Spain): phylogenetic and epidemiological analyses

Area of Science:

• Hepatology
• Virology
• Epidemiology

Background:

• Hepatitis C virus (HCV) is a primary cause of chronic hepatitis, potentially leading to liver cirrhosis and hepatocellular carcinoma.
• HCV exhibits high genetic variability, resulting in classification into six major clades.
• Understanding HCV genotype distribution is crucial for effective treatment and public health strategies.

Purpose of the Study:

• To investigate the distribution of HCV genotypes in Malaga, southern Spain.
• To characterize the prevalence and subtypes of HCV genotype 4 in the study population.
• To analyze the epidemiological and phylogenetic features of HCV-4c and HCV-4d subtypes.

Main Methods:

• A commercial HCV genotyping procedure was applied to 678 patients.
• HCV-4 subtype distribution was analyzed in 69 patients.
• Sequencing of the non-structural 5B gene (393 bp) was performed on 36 HCV-4c/4d patients.
• Phylogenetic analysis was used to distinguish between HCV-4c and HCV-4d subtypes.

Main Results:

• HCV genotype 4 showed a high prevalence (10.2%) in Malaga.
• HCV-4 subtypes 4c/4d were the most prevalent (76.8% of HCV-4 cases).
• Phylogenetic analysis clearly distinguished between HCV-4c and HCV-4d subtypes.
• HCV-4c/4d infections were found in both intravenous drug users (69%) and non-intravenous drug users (31%).

Conclusions:

• HCV genotype 4, particularly subtypes 4c and 4d, is prevalent in Malaga, southern Spain.
• These subtypes are circulating among diverse populations, including intravenous drug users and non-users.
• Phylogenetic and epidemiological data suggest the ongoing extension of HCV-4c and -4d subtypes in the Malaga area.