Understanding hepatitis C

Hepatitis C is a contagious viral disease that may damage your liver. It’s caused by the hepatitis C virus (HCV). This disease has several genotypes, also called strains, each with a specific genetic variation. Some genotypes are easier to manage than others.

In the United States, hepatitis C genotype 3 is less commonly contracted than genotype 1, but genotype 3 is also harder to treat. Read on to discover what it means to have genotype 3 and how it’s treated.

According to the Centers for Disease Control and Prevention (CDC), currently seven HCV genotypes have been identified. Each genotype has its own subtypes — totaling more than 67 overall.

Because each genotype may be treated with different medications for different durations, it’s important to identify which genotype a person has. The genotype of the infecting virus doesn’t change. Although in rare cases, someone may be infected with more than one genotype of the virus at once.

Approximately 22 to 30 percent of all people with HCV infections have genotype 3. The clinical research on therapies for this genotype had trailed behind research and treatment effectiveness for other genotypes in the past. However, this gap is now believed to be closing.

Research into better treatments is important as there’s evidence to suggest that people with this genotype experience a faster progression of liver fibrosis and cirrhosis. This means that your liver tissue may thicken and scar faster than that of someone with a different genotype.

People with genotype 3 may have a higher risk of severe steatosis, which is fat accumulation in the liver. This could cause your liver to swell with inflammation and worsen scarring. This can also contribute to your risk of liver failure.

This genotype may increase your risk for hepatocellular carcinoma as well. Hepatocellular carcinoma is the most common form of primary liver cancer, often occurring in people with chronic hepatitis B or C.

With the HCV infection, it’s important to know which genotype a person has. This will allow a healthcare provider to give the best care by creating a treatment plan specific to the type of HCV.

Overall, this is a relatively new component of HCV treatment. Before 2013, there wasn’t a reliable way to distinguish between the different HCV genotypes that may be present in a person with the infection.

In 2013, the Food and Drug Administration (FDA) approved the first genotyping test for people with HCV.

Various nucleic acid amplification tests can differentiate between the following genotypes:

  • 1 and its subtypes
    • 1a
    • 1b
  • 2
  • 3
  • 4
  • 5
  • 6

To do this, your doctor firsts obtain a sample of your blood plasma or serum. In the test, genetic material (the RNA) that’s present inside the HCV virus is analyzed. During this time, several identical copies of complementary DNA material are produced. This testing can help identify the unique HCV genotype or genotypes present.

This test shouldn’t be used as the first diagnostic tool for determining if a person has HCV infection.

However, anyone who’s at risk for HCV should at least be tested for the disease with a screening test.

Diagnosing HCV

HCV is diagnosed through a screening blood test. This test is usually performed at a local diagnostic lab or health facility.

You’re considered to be at risk if any of the following applies:

  • You were born between 1945 and 1965.
  • You took illegal injected drugs at least once at any time in your life.
  • You had a blood product transfusion or organ transplant before 1992.
  • You’re a healthcare worker with a needlestick injury that may have exposed you to HCV.
  • You have HIV.
  • You were born to a woman who was HCV-positive and you’ve never been tested for HCV.

The initial test looks for antibodies formed against HCV in your blood. If antibodies are present, it indicates that you’ve been exposed to the virus at some point. But this doesn’t necessarily mean you have HCV.

If you test positive for HCV antibodies, your doctor will order additional blood tests to determine if the virus is active and what your viral load is. Your viral load refers to the amount of the virus that’s in your blood.

Some people’s bodies may fight off HCV without treatment, while others may develop the chronic form of the disease. Genotype testing will also be part of the additional blood tests.

Although there are treatment guidelines for each genotype, there’s not a one-size-fits-all option. Treatment is individualized. Successful treatment plans are based on:

  • how your body responds to medications
  • your viral load
  • your overall health
  • any other health conditions you may have

HCV usually isn’t treated with prescription medications unless it’s chronic. Treatment typically lasts between 8 and 24 weeks and includes combinations of antiviral drugs that attack the virus. These treatments can help minimize or prevent liver damage.

It’s been shown that genotype 3 is less likely to respond to a typical course of the new direct-acting antiviral agents (DAAs) approved by the FDA. Regimens more likely to fail may include:

  • boceprevir (Victrelis)
  • simeprevir (Olysio)

It’s unclear exactly why genotype 3 is so resistant to these treatments.

Genotype 3 has been found to respond better to newer drug combinations, including:

  • glecaprevir-pibrentasvir (Mavyret)
  • sofosbuvir-velpatasvir (Epclusa)
  • daclatasvir-sofosbuvir (Sovaldi)

Genotype 1 is the most common variation of HCV in the United States and worldwide. Approximately 70 percent of U.S. people with HCV have genotype 1.

Worldwide, data suggests that approximately 22.8 percent of all cases are genotypes 2, 4, and 6. Genotype 5 is the rarest, comprising less than 1 percent of the global population.

Genotype 3 is associated with a higher risk of liver cancer, faster development of fibrosis and cirrhosis, and mortality. Because of this, it’s important to determine which HCV genotype someone has if they’ve been diagnosed with the HCV infection.

This allows someone with this genotype to kick-start their treatment, potentially limiting the damage done to their liver and other serious side effects. The longer diagnosis and treatment are put off, the more difficult treatment will become and the higher the risk for complications.