Monitoring treatment response

Hepatitis C viral load testing is used to monitor how hepatitis C treatment is working and, sometimes, to help determine the length of treatment.

A healthcare provider may recommend hepatitis C viral load testing at different stages:

• Before beginning treatment: This provides a starting (“baseline”) amount of hepatitis C in the blood. As treatment continues, this baseline viral load is compared to the viral loads taken during treatment.

• During treatment: The timing of hepatitis C viral load tests during treatment depends on a person’s genotype, healthcare provider preferences, the treatment regimen and provincial lab guidelines.

  Generally, the earlier the hepatitis C virus becomes undetectable, the higher the chance of sustained virological response (SVR). If viral load is undetectable after four weeks of treatment (eight weeks if the regimen includes boceprevir), it is called a rapid virological response (RVR).

  If the viral load is undetectable at week 12, it is called a complete early virological response (cEVR). If the viral load decreases by two or more "logs" after 12 weeks of treatment, it is called a partial early virological response (pEVR). RVR and EVR are both good signs that treatment will be successful for a person and it might be possible to shorten the length of treatment. On the other hand, if there is no EVR, some healthcare providers will recommend stopping treatment and some insurance programs will stop covering the cost of treatment.

• End of treatment: Healthcare providers check to see if the virus is undetectable at the end of treatment. If it is, it is called an end of treatment response (ETR).

• Six months after the end of treatment: Testing at this stage will only happen when viral load was undetectable at the end of treatment. SVR is when viral load is still undetectable six months after the end of treatment.

Revised 2012.