Transmission of hepatitis C virus among intravenous drug users in the Uppsala region of Sweden

Abstract

BackgroundEpidemiology and transmission patterns of hepatitis C virus (HCV) are important subjects as we enter a new era of treatment with directly acting antivirals (DAAs). The highest prevalence of HCV in developed countries is found among intravenous drug users (IDUs), where unsafe needle sharing practices provide the main route of infection. Efforts to prohibit the continuous spread of HCV among these groups have been initiated by the community services and health care providers. Our goal was to understand how HCV was transmitted among IDUs within a limited population group. We provide a retrospective study (2005–2007) of the HCV transmission patterns in a population of IDUs in the Uppsala region of Sweden.MethodEighty-two serum samples were collected from IDUs in Uppsala County. Our reverse transcription nested polymerase chain reaction (RT-nested PCR) and sequencing method enabled a comprehensive genetic analysis for a broad spectrum of genotypes of two relatively conserved regions, NS5B and NS3, that encodes for the viral polymerase and protease, respectively. HCV RNA in serum samples was amplified and sequenced with in-house primers. Sequence similarities between individuals and subgroups were analyzed with maximum likelihood (ML) phylogenetic trees. Published HCV reference sequences from other geographic regions and countries were also included for clarity.ResultsPhylogenetic analysis was possible for 59 NS5B (72%) and 29 NS3 (35%) sequences from Uppsala patients. Additionally, we also included 15 NS3 sequences from Örebro patients, making a total of 44 NS3 sequences for the analysis. By analyzing the NS3 sequences, two transmission sets were found between the IDUs (>98% sequence identity), with one set consisting of two individuals and another set consisting of three individuals. In addition, the phylogenetic analysis done with our serum samples displayed clusters that distinguished them from the reference sequences.ConclusionOur method seems to enable us to trace the HCV transmission between IDUs. Furthermore, the method is fairly independent of the time of infection because the method uses relatively conserved HCV sequence regions (i.e. NS5B and NS3).

The Influence of Hepatitis C Virus Genetic Region on Phylogenetic Clustering Analysis

“…Although the Core region is often used in phylogenetic analysis [ 28 – 30 ], this study found it was too conserved for clustering analysis. This study also found partial NS5B to be less informative than Core-E2 region, while other studies have used it for phylogenetic analyses [ 31 – 35 ] and suggest it is particularly suitable dating the introduction of an infection into a population using Bayesian methodologies [ 36 – 38 ].…”

Hepatitis C Infection among Health Care Workers in Aswan: Seroprevalence and Risk Factors

“…(25,26) The sharing of equipment for intravenous use of drugs may lead to transmission of HCV virus. (27) The majority of HCV-Ab negative HCWs washed their hands after exposure to blood or body fluid. This was comparable to the results of Munier et al, (14) who declared that hand hygiene is a cost-effective intervention to prevent heath care settings infections.…”