Determining the source of nosocomial transmission in hemodialysis units in Tunisia by sequencing NS5B and E2 sequences of HCV

Abstract

Hepatitis C virus infection is a significant problem in hemodialysis units. HCV is very variable genetically with six genotypes. Clinical and epidemiological investigation of a new infection requires the determination of both the genotype and the strain of the HCV involved. A prospective, epidemiologic study of 395 dialysis patients in Tunisia was conducted from November 2001 to November 2003 to identify the source of nosocomial transmission using phylogenetic analysis of NS5b and E2 sequences. Hepatitis C infection was diagnosed by screening for anti-HCV antibodies and HCV RNA in sera using third generation ELISA and a qualitative RT-PCR assay. HCV strains were genotyped by sequencing the NS5b region. The genetic relatedness of the HCV strains was studied by sequencing the NS5b and the HVR-1 regions of the HCV genome. Two de novo cases of HCV infection were detected during the follow-up. One of them has been described previously. The case described in this study occurred in a center in which 12 patients were already infected with HCV strains belonging to genotypes 1b (n = 8) and 1a (n = 4). Phylogenetic analysis of the NS5b region from the HCV strains circulating in this center disclosed four clusters, confirmed by analysis of the HVR-1 region, providing strong evidence for nosocomial infection. Epidemiological data showed that these patients were dialyzed during the same shift and in the same area. Phylogenetic analysis of NS5b sequences is useful for determining the HCV genotype and providing evidence of nosocomial transmission.

Human herpesvirus 8 shedding in the mouth and blood of hemodialysis patients

“…To detect possible intra‐unit HHV‐8 transmission in patients with chronic renal failure, the hypervariable region (K1/V1) was analyzed and compared between patients undergoing hemodialysis. Previous studies have documented intra‐unit hepatitis C virus transmission in hemodialysis units, with phylogenetic analysis revealing clustering between patients who were dialyzed during the same shift and in the same area [Hmaied et al, 2007]. In the current study, however, phylogenetic analysis revealed that none of the HHV‐8‐infected patients with chronic renal failure carried identical K1/V1 sequences.…”

Dissection of familial correlations in hepatitis C virus (HCV) seroprevalence suggests intrafamilial viral transmission and genetic predisposition to infection

“…Of the 96 strains, 95 (99%) were genotype 4 while the remaining one was genotype 1. The NS5B region is commonly analysed to distinguish between related and unrelated isolates of the same subtypes especially in HCV nosocomial transmission that occurred over a period of several years 21 – 23. This region is known to be stable over time24 and was recommended for the study of ancient HCV transmission events 25.…”

Intrafamilial viral transmission is not the main cause of the high prevalence of hepatic C virus infection in a village, Putian county, China

“…[23][24][25][26][27][28] However, the phylogenetic analysis of a fragment from the virus isolates has provided an important tool in establishing genetic relatedness of viruses, [29][30][31] which has been proven to be successful for the study of the different routes of transmission. 9,28,[30][31][32][33] The results of the sequence analysis in this study showed that the sequence identity values from family pairs were not higher than that of unrelated subjects. Kimura distances from family pairs were also not shorter than that of unrelated subjects.…”