Viral hepatitis C cascade of care: a population-level comparison of immigrant and long-term residents

Background and Aims — Viral hepatitis C represents a major global burden, particularly among immigrant-receiving countries such as Canada, where knowledge of disparities in hepatitis C virus among immigrant groups for micro-elimination efforts is lacking. We quantify the hepatitis C cascades of care among immigrants and long-term residents prior to the introduction of direct-acting antiviral medications.

Methods — Using laboratory and health administrative records, we described the hepatitis C virus cascades of care in terms of diagnosis, engagement with care, treatment initiation, and clearance in Ontario, Canada (1997-2014). We stratified the cascade by immigrant and long-term resident groups and identify drivers at each stage using multivariable Poisson regression.

Results — We included 940,245 individuals in the study with an estimated hepatitis C prevalence of 167,923 (1.4%) overall, 23,759 (0.7%) among all immigrants, and 6,019 (1.1%) among immigrants from hepatitis C endemic countries. Overall there were 104,616 individuals with reactive antibody results, 73,861 tested for viral RNA, 52,388 with viral RNA detected, 50,805 genotyped, 13,159 on treatment, and 3,919 with evidence of viral clearance. Compared to long-term residents, immigrants showed increased nucleic-acid testing (aRR: 1.09 [95%CI: 1.08, 1.10]), treatment initiation (aRR: 1.46 [95%CI: 1.38, 1.54]), and higher clearance rates (aRR: 1.07 [95%CI: 1.03, 1.11]).

Conclusions — Hepatitis C virus is more prevalent among long-term residents compared to immigrants overall, however immigrants from endemic countries are an important subgroup to consider for future screening and linkage to care initiatives. These findings are prior to the introduction of newer medications and provide a population-based benchmark for follow-up studies and evaluation of treatment programs and surveillance activities.