Hep C Elimination Tool: Frequently Asked Questions (FAQs)

Hep C Elimination Tool: Frequently Asked Questions (FAQs)

The tool was launched in 2020 to support countries in budget-based planning and development of national strategies for HCV elimination. The tool was based on an existing, published underlying model. Email globalhep [at] taskforce.org with any additional questions or to learn more.

 Read more about Frequently Asked Questions

Is there a tool available for hepatitis B?

There is a great need for a similar resource to the Hepatitis C Elimination Tool for hepatitis B. Although the funding for such a tool has not been identified, there are a number of expert hepatitis B modelers that can be called upon to conduct country-level analyses with their existing models. Contact the Coalition at globalhep [at] taskforce.org with possible inquiries. 

What assumptions about the HCV epidemiologic burden does the tool make?

The tool is calibrated to each local country context. More information on the tool's under methodology can be found here: https://www.globalhep.org/node/108723

Why does the tool show no possible strategies?

The tool will only show testing and treatment strategies that are feasible for elimination. If no strategies are showing, then there may be a couple of reasons:

  • The screening policy may be too conservative if only risk-based is selected. Try selecting universal or age-cohort screening.
  • The selected testing algorithm may not be feasible given the assumptions on loss-to-follow-up. Lab-based strategies are assumed to be have lower linkage to care. Try adjusting the algorithm or combination of algorithms. 
  • If adjusting the screening policy or testing algorithm does not show any strategies, elimination goals set may be too ambitious given the current burden of disease and baseline testing and treatment coverage. Try lowering the goals.

How do I add my country to the tool?

We are looking to add more countries! Email the Coalition at www.globalhep [at] taskforce.org to learn how to get started.

What does the tool assume about HCV reinfection?

In short, the reinfection rate was assumed to be 30% of the original infection rate.

Additional information:

In HEP-SIM model, there are two types of infections: first time infection from susceptible population and reinfection from cured population.

First, each individual in susceptible population can be newly infected with HCV and the number of new infections every year is determined by the following equation:

Number of infections = α (I+D/N)

where α is the infection rate,  S indicates the susceptible population size, I indicates the infected but diagnosed population size, D indicates the infected and diagnosed population size, and N is the total population size.  In fact, (I+D/N) represents the chronic HCV prevalence in a given year.

Second, each individual in cured population can be reinfected with HCV and the number of new reinfections every year is determined by the following equation

Number of refinections= R 𝛿 α (I+D/N)

where (I+D/N)  indicates the prevalence of chronic HCV, R indicates the cured population size, and 𝛿 is weight parameter to modify the infection rate α. Since cured patients might be more cautious and have less risky behaviors, we assumed  𝛿 ∈ (0,1). Therefore, reinfection rate, denoted by 𝛿 α, is smaller than the original infection rate α.

In the case of HCV elimination tool, we assumed 𝛿 = 0.3.

 

What does the tool assume about linkage to care?

Coming soon...

Last day updated 10 Nov 2021