Social Science Research Network | 2021
An Outbreak of Hepatitis C Virus Infection Among Transfused Thalassemia Patients: Root Cause Analysis, Phylogenetic Epidemiology and Antiviral Therapy
Abstract
Background: Occurrence of HCV infection is reduced by effective risk management procedures, but patient-to-patient transmission continues to be reported in healthcare settings.\xa0We report an outbreak of 11 patients with HCV acute hepatitis (seven new infections and four re-infections) among\xa0128 thalassemia\xa0patients followed at a Hospital in Sicily. \n \nMethods All patients with acute hepatitis and known chronic infection were tested for HCV-RNA, HCV genotyping, and NS3, NS5A and NS5B HCV-genomic regions sequencing.\xa0\xa0To identify transmission clusters we built phylogenetic trees\xa0for each gene employing Bayesian methods.\xa0 \n \nFindings All patients\xa0with acute hepatitis\xa0were infected with HCV genotype 1b. Root-cause analysis, including\xa0a lookback procedure, led us to exclude\xa0blood donors as the source of HCV\xa0transmission.\xa0The phylogenetic analysis, conducted on seven patients with acute infection and eight patients with chronic infection, highlighted four transmission clusters including at least one patient with chronic and one patient with acute HCV infection.\xa0All patients in the same cluster received a blood transfusion at the Thalassemia Unit during the same day.\xa0Two patients with acute hepatitis spontaneously cleared HCV within four weeks and\xa0nine patients\xa0received ledipasvir plus sofosbuvir for six weeks, all achieving a sustained virological response.\xa0 \n \nInterpretation Combined use of root cause analysis and molecular epidemiology was effective in ascertaining the origin of the HCV outbreak.\xa0\xa0Antiviral therapy avoided the chronic progression of the infection and further spread in care units and in the family environment. \n \nFunding Regional Health System of Sicily and\xa0by the Italian Ministry of Health (RF-2016-02362422). \n \nDeclaration of Interest: V.D.M received speaking and/or consulting fees by Abbvie, Gilead, MSD, Intercept. F.C-S. received speaking and/or consulting fees by Abbvie, Gilead, Janssen, Merck/MSD, ViiV . All other authors have nothing to declare. \n \nEthical Approval: This study was conducted in agreement with the Helsinki Declaration. Since the available DAAs were not licensed for acute hepatitis, the regional health authorities and local ethics committee authorized DAA therapy in patients with diagnosis of acute hepatitis