Hepatitis C virus genotypes in hemophiliacs in the state of Minas Gerais, Brazil

BACKGROUND: Hepatitis C virus (HCV) is a positive-strand RNA virus composed of at least 10 genotypes and dozens of subtypes. Six major genotypes can b e distinguished by restriction fragment length polymorphism (RFLP) analysis of the amplified 5' noncoding region (NCR) of the genome. The genotypes ar e unequally distributed throughout the world. Types 1 and 3 are most common in Europe and the United States. Although fewer studies have been performe d in Brazil, the pattern seems to mirror that in the other areas. HCV infec tion is highly prevalent among hemophiliacs and is a major cause of chronic liver disease. STUDY DESIGN AND METHODS: This study investigated a sample of the hemophili ac population in the state of Minas Gerais, Brazil, by RFLP analysis of the 5' NCR. RESULTS: It was observed that 84.1 percent were of genotype 1 and 13.6 perc ent of genotype 3. Sequence analysis of nine isolates confirmed the RFLP re sults and determined that all of the type 1 isolates belonged to subtype la . Phylogenetic analysis by parsimony and distance revealed that lineages of genotypes 1, 2, and 3, and 4 could be separated. The isolates of type 3 fr om this study were distinct from published sequences, which possibly indica ted their different geographical origin. CONCLUSION: Although the frequency of genotypes observed (types 1 and 3) am ong hemophiliacs in the state of Minas Gerais was higher than that in the s outhern part of the country, these frequencies were not different from thos e in other groups of patients in Brazil and other countries studied. Furthe r investigation is needed of the evidence that the type 3 isolates observed in these studies are significantly different from other isolates previousl y characterized by sequence analysis.