Recent High Incidence of Fulminant Hepatitis in Samara, Russia: Molecular Analysis of Prevailing Hepatitis B and D Virus Strains

Abstract

Until 1991, the Russian city of Samara was largely isolated from other parts of Russia and the rest of the world. Very recently, Samara has seen an alarming increase in the incidence of hepatitis. The proportion of fulminant cases is unusually high. We wanted to assess the roles of hepatitis B virus (HBV) and hepatitis D virus (HDV) in acute viral hepatitis in this region by analyzing the prevailing strains of both and by determining their genotypes and possible origin. Serum samples were screened for different serological markers and by PCR followed by direct sequencing. Of the 94 HBV-positive samples (80% of which were acute infections), 37 (39%) were also HDV positive. Sixty-seven percent of the patients had anti-HCV antibodies. Twenty-five percent of all patients in the study had fulminant hepatitis. Statistically significant sex differences were found among fulminant cases. For HBV, the core promoter sequences of 62 strains were determined and all but one were found to be of genotype D. None of these had any deletions. Only one strain, from a patient with fulminant fatal hepatitis, showed multiple mutations. The pre-S2 region sequences of 31 HBV strains were also compared. Phylogenetically, these fell into two distinct groups within genotype D, suggesting different origins. For HDV, part of the region encoding the δ-antigen was sequenced from four strains. All proved to be of genotype I and were similar to Far Eastern and Eastern European strains. The contribution of intravenous drug use to the sharp increase in viral hepatitis in this unique setting is discussed.

Multiple genotypes and subtypes of hepatitis B and C viruses in Belarus: similarities with Russia and western European influences

“…No sequence data were available from the latter countries. In contrast, genotype D is predominant in Russia [35], accounting for >90% of isolates, consisting mainly of subtype D2 (80.6%), followed by subtype D3 (12.9%) and subtype D1 (3.2%). Thus, as in the Baltic States, the genotype distribution found in Belarus resembles that found in Russia, although not without clear influences from western Europe.…”

The increasing prevalence of hepatitis delta virus (HDV) infection in South London

“…In contrast to the findings in Italy, the majority of HDV patients in the present study were younger than 50 years indicating that individuals are still contracting the infection. Despite the decline of HDV in traditionally endemic areas, outbreaks of HDV infection have occurred around the world [Dalekos et al, 1995;Sakugawa et al, 1995;Singh et al, 1995;Flodgren et al, 2000;Manock et al, 2000]. These findings indicate that HDV is not disappearing, as previously suggested [Gaeta et al, 2000], rather its epidemiology is changing.…”

Epidemiology of Hepatitis D

“…In an outbreak of severe and fulminant HBsAg hepatitis that occurred in Samara at the end of the 1990s, HDV infection was found in 39% of 94 cases; HDV was genotype-1 in the four cases examined. 67 An outbreak of hepatitis D occurred in the mid-2010s in a village of 133 inhabitants in the West coast of Greenland, 68 where 48% of the inhabitants were under 20 years of age and 27% were carriers of the HBsAg; within one year, 68% had become anti-HD positive, all with elevated liver enzymes. In Mongolia, HDV superinfection was the cause of acute hepatitis in 30 young HBsAg carriers in the period December 2004 through January 2005; in 2004, 13.6% of Mongolian HBsAgpositive children were reported to have HDV RNA in their blood.…”