HEPATITIS-DELTA GENOTYPES IN CHRONIC DELTA-INFECTION IN THE NORTHEASTOF SPAIN (CATALONIA)

Background/Aims: Based on genetic analysis of variants obtained around the world, three genotypes of the hepatitis delta virus have been def ined. Hepatitis delta virus variants have been associated with differe nt disease patterns and geographic distributions. To determine the pre valence of hepatitis delta virus genotypes in the northeast of Spain ( Catalonia) and the correlation with transmission routes and clinical d isease, we studied the nucleotide divergence of the consensus sequence of HDV RNA obtained from 33 patients with chronic delta hepatitis (24 were intravenous drug users and nine had no risk factors), and four p atients with acute self-limited delta infection. Methods: Serum HDV RN A was amplified by the polymerase chain reaction technique and a fragm ent of 350 nucleotides (nt 910 to 1259) was directly sequenced. Result s: Genetic analysis of the nucleotide consensus sequence obtained show ed a high degree of conservation among sequences (93% of mean). Compar ison of these sequences with those derived from different geographic a reas and pertaining to genotypes I, II and III, showed a mean sequence identity of 92% with genotype I, 73% with genotype II and 61% with ge notype III. At the amino acid level (aa 115 to 214), the mean identity was 87% with genotype I, 63% with genotype II and 56% with genotype I II. Conserved regions included the RNA editing domain, the carboxyl te rminal 19 amino acids of the hepatitis delta antigen and the polyadeny lation signal of the viral mRNA, Conclusions: Hepatitis delta virus is olates in the northeast of Spain are exclusively genotype I, independe ntly of the transmission route and the type of infection. No hepatitis delta virus subgenotypes were found, suggesting that the origin of he patitis delta virus infection in our geographical area is homogeneous.