Hepatitis C in the Post-DAA Era

Hepatitis C in the Post-DAA Era

A Structured Summary of the Lecture by Prof. Paul Kwo, MD (Stanford University)

1. Main Clinical Topics Discussed

• Global and US epidemiology of hepatitis C virus (HCV) infection in the post-direct-acting antiviral (DAA) era
• The evolving demographic profile of HCV-infected populations
• HCV elimination targets and the WHO 2030 framework
• The intersection of HCV with injection drug use (IDU) and the opioid epidemic
• Challenges in the cascade of care, including diagnosis gaps
• Treatment as prevention (TasP) as a public health strategy
• Impact of the COVID-19 pandemic on HCV elimination efforts

2. Key Learning Points, Guidelines, and Recommendations

• WHO 2030 Elimination Targets:

- 90% of infected individuals diagnosed

- 80% of diagnosed individuals treated

- 65% reduction in HCV-related mortality

- Goal: eliminate viral hepatitis as a major global public health threat

• Distinction between eradication and elimination:

- *Eradication* = permanent global reduction to zero incidence; intervention no longer required (e.g., smallpox)

- *Elimination* = reduction to zero incidence in a defined geographic area; ongoing intervention required (e.g., polio)

- HCV elimination is feasible without a vaccine — precedent exists (e.g., onchocerciasis/river blindness eliminated with ivermectin)

• Treatment as Prevention (TasP):

- All individuals with chronic or acute HCV should be treated promptly

- Immediate treatment reduces onward transmission, particularly among people who inject drugs (PWID)

• Screening and diagnosis:

- Point-of-care (POC) testing is increasingly important as HCV prevalence declines and the ratio of anti-HCV antibody positivity to active viremia decreases

- Universal HCV screening should be expanded, particularly in younger age groups and pregnant women

• Priority populations requiring active intervention:

- PWID (dominant risk factor for new infections)

- Women of childbearing age and pregnant women

- Individuals on opioid substitution therapy (e.g., buprenorphine)

3. Specific Clinical Data, Statistics, and Study Results Cited

• Global burden: Approximately 50 million individuals currently infected with HCV worldwide (WHO data); highest burden in Europe, Southeast Asia, and the Western Pacific region
• US epidemiology:

- Acute HCV cases rose from 2016 but have recently leveled off; COVID-19 caused a temporary increase in cases

- Geographic hotspots include the US Midwest, New York, and New England

- Highest rates of acute HCV now in the 20–39 and 40–49 age groups, displacing the historical 1945–1965 birth cohort

- Men account for approximately 2:1 ratio of newly reported chronic HCV cases

• PWID statistics:

- HCV prevalence among PWID: 60–80%

- In the US, approximately two-thirds of PWID are chronically infected

- PWID account for 60–85% of all new HCV cases in the US

- HCV is 10-fold more infectious than HIV; can survive in needle barrels and on drug paraphernalia (cookers, cotton filters) for days

• Pregnant women:

- HCV prevalence in pregnant women rose from 0.05% (2000) to 0.49% (2019)

- In HIV-positive pregnant women, risk has approximately doubled to ~10.8%

• Cascade of care gaps (US NHANES data):

- Anti-HCV positive individuals: ~4.5 million (2003–2010), declining to ~2.7 million

- By 2016, only 57% of anti-HCV positive individuals were viremic (RNA positive), highlighting the need for reflex RNA testing and POC diagnostics

• Treatment as prevention modeling:

- One untreated active injector can potentially infect up to 20 others within the first 3 years of diagnosis

• COVID-19 impact:

- Marked increase in drug