1. Total population

• In 2016, 1% (2.4 million) of the US adult population were chronically infected with HCV

2. Current and former PWID

• 80% of these aquired their infections through IDU
• 53.1% of current PWID are infected with HCV in 2016

3. Scaling to a population (assuming a steady PWID population)

• In 2007 there were 2,248,500 PWID (current)
• In 2016 there were 1,193,954 (0.531*2,248,500) HCV infected PWID (current)
• In 2016 there were 726,046 (0.8* 2.4million - above) HCV infected former PWID

4. Scaling to a population (assuming a growing PWID population)

• In 2007 there were 2,248,500 PWID (current)
• Allow PWID population to grow as a model fitting parameter

5. Incidence trend scaling fitted as a multiplier for probability of infection

6. General population (excluding current and former PWID

• General population (20% of 2.4 million) of 480,000 chronically infected HCV subjects in 2016

7. Endemic trend for general population

• Chronic HCV is assumed to be endemic in the general population and in steady state, i.e. constant