NEW YORK (Reuters Health) – HCV genotype 4, previously limited to Egypt and parts of Africa, has now spread to southern Europe and other parts of world, an international panel says in their review published online 9th December in the Journal of Hepatology. Genotype 4 or the Egyptian genotype, now accounts for roughly 20% of HCV infections in Europe and worldwide.
“This strain of HCV is more difficult to treat than GT(genotype) 2 and 3, which has traditionally been relatively more common in Europe,” Dr. Stephen Harrison, panelist from the Brooke Army Medical Center, Houston, Texas, said in an email to Reuters Health.
HCV is classified into six genotypes based on nucleotide sequences.(P 6, l 8,9)While genotype 4 is uncommon in USA with a prevalence of 1%,(P 9, last para, l 2) it accounts for 90% of HCV infections in Egypt,Dr. Mahmoud A Khattab, lead author from the University of Minia, Egypt and colleagues point out.
The HCV-4 epidemic in Egypt probably traces its origins to the anti-schistosomiasis campaign involving parenteral injections on a large scale. Whereas sexual transmission and traditional medical practises like scarification were responsible for its spread through Africa and Middle East, immigration and intravenous drug use may have spread the virus worldwide, the researchers postulate.
Though the clinical features and microscopy are similar to that of other genotypes, co-existent schistosomiasis hastens progress of hepatic fibrosis and reduces chances of spontaneous resolution. Severe steatosis without sinusoidal fibrosis is a typical finding on liver biopsy, the panelists described.
HCV-4, like the other types in a major cause of chronic liver disease. “A possible association had been suggested between HCV-4 and hepatocellular carcinoma(HCC) based on the similarity of distribution of HCC and HCV-4 in Egypt,” the panelists hypothesized.
“We approach the treatment of GT 4 virus the same way we do GT 1 virus. Current standard of care is 48 weeks of pegylated interferon and weight based ribavirin,” Dr. Harrison said in his email.
“Among the genotypes, 1, 4 and 6 appear to be the most resistant to treatment, with success rates of about 50% in viral clearance with a longer course of treatment. This compares to much more favourable rates of about 70-85% cure rate with shorter treatment durations in patients with genotypes 2 and 3,” Dr.Sam Lee panelist from the Liver Unit of University of Calgary, Canada, told Reuters Health.
“About 5-35% of patients stop treatment prematurely due to side effects,” Dr. Lee pointed out.
HIV co-infection, cirrhosis and high initial viral load were the main predictors of a delayed treatment response, the panelists write.
According to the panelists, “response-guided therapy