Distribution of Hepatitis C Virus Genotypes in Canada: Results from the LCDC Sentinel Health Unit Surveillance System

Abstract

In a sentinel hepatitis surveillance study conducted by sentinel health units, 1469 patients were enrolled, and 959 (65.3%) were positive for antibody to hepatitis C virus (HCV). Samples from 387 patients (40.4%) were tested for HCV RNA, and 289 (74.7%) were positive for RNA. The major risk factor for HCV infection was injection drug use, reported in 71% of cases. The genotyping of HCV isolates showed that subtype 1a (48%) was predominant in Canada. The other subtypes detected were 1b (19%), 2a (6%), 2b (3%), 3a (22%) and 4a (1%). In Winnipeg, Manitoba, subtype 3a (47%) was more prevalent than subtype 1a (37%), and, in Guelph, Ontario, both subtypes 1a and 3a had equal (40%) distribution. The prevalence of subtype 3a was significantly higher in injection drug users (27%) than in nonusers (10%) (P<0.005). In Canada, injection drug use is the major risk factor for HCV infections, and subtype 1a is more prevalent.

Directly observed therapy for the treatment of hepatitis C virus infection in current and former injection drug users

“…Overall, 55% of the individuals in this study were infected with genotypes 2 or 3 (genotype 2, 15%; genotype 3, 40%), which is consistent with epidemiologic data in Vancouver demonstrating a higher prevalence of genotype 3 infection among injection drug users 23 . This is also consistent with other reports from Canada, Australia and Europe demonstrating a higher prevalence of HCV genotype 3 infection among IDU 24–26 . Given the higher response rates in genotype 2 and 3 subjects, this has important implications for strategies specifically targeting HCV therapy in this subgroup of patients.…”

Cost-effectiveness of screening for hepatitis C in Canada

“…The conventional upper limit of applied cost-effectiveness thresholds [50][51][52] varies among countries, from $50 000 to $120 000 per QALY. The results of multiple 1-way deterministic and probabilistic sensitivity analyses provided evidence that the screen-andtreat approach is likely to be cost-effective, taking into consideration the uncertainty of the model's parameters.…”

The management of chronic hepatitis C: 2018 guideline update from the Canadian Association for the Study of the Liver

“…Genotype 1: Genotype 1 is the most prevalent HCV genotype in Canada and most patients are infected with either genotype 1a or 1b. 60 Subtyping is important because some regimens are more effective against genotype 1b than 1a. 61 Treatment recommenda tions for treatmentnaive patients without cirrhosis (Table 3) and with compensated cirrhosis (Table 4) are listed by genotype and subtype.…”