What to know about the types of hepatitis C

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A 2014 article indicates there are seven known HCV genotypes and 67 subtypes.

The United States Department of Veterans Affairs explains how the hepatitis C genotype is a type, or strain, of HCV. The most common HCV genotypes in the United States include:

• genotype 1
• genotype 2
• genotype 3

This further classifies into 1a and 1b, and 2a, 2b, and 2c. Of these subtypes, 1a, 1b, 2, and 3 are most common in the United States.

Learn all about hepatitis C.

How hepatitis C affects people

Most people with hepatitis C are asymptomatic (do not have symptoms). However, someone with acute hepatitis C may show symptoms within 1–3 months. Symptoms may include:

• jaundice
• nausea and vomiting
• dark yellow urine.

Chronic hepatitis C may only cause symptoms when complications have arisen, including:

• liver damage
• cirrhosis or scarring
• liver failure
• liver cancer

Find out how hepatitis C affects people in the early stages.

According to the United States Department of Veterans Affairs in the United States, approximately:

• 75% of people have genotype 1 (subtypes 1a or 1b)
• 20–25% of people have genotypes 2 or 3
• a small number of people have genotypes 4, 5, or 6

According to Treatment Action Group, all HCV genotypes cause the same amount of liver damage. However, people with genotype 1, particularly subtype 1b, are at greater risk of developing liver cirrhosis than people with other genotypes. Genotypes 1b and 3 may increase a person’s risk of developing liver cancer.

Most people with HCV tend to have a single genotype rather than multiple genotypes.

However, people who travel between regions where other HCV genotypes are more common may have exposure to different HCV genotypes, leading to a mixed infection.

According to an article in the Lancet, genotype 4 is more common in sub-Saharan Africa, while genotype 1 is more prevalent in Central and Western Europe, and 1a and 1b subtypes are most common in the United States.

The CDC suggests superinfection of more than one HCV genotype is possible if risk behaviors for HCV infection continue. However, they suggest that superinfection does not appear to complicate treatment since HCV direct-acting antivirals (DAAs) are available.

People should have relevant screening, testing, and treatments based on their HCV genotype.

Learn more about hepatitis C treatment.

Hepatitis C testing requires a Food and Drug Administration (FDA) approved anti‑HCV test. This test uses a blood sample to test for HCV antibodies. When screening for HCV, people may have several tests to confirm a diagnosis.

Once a medical professional has diagnosed someone with HCV, the doctor will run further tests to assess the genotype and the viral load level. The viral load level refers to how much HCV is in the blood.

HCV genotypes differ due to their specific ribonucleic acid (RNA) sequence, or genetic makeup. Experts perform genotype testing by looking for specific or slight variations in the RNA sequence.

Learn more about hepatitis C testing.

According to the United States Department of Veteran Affairs, the type of genotype a person has determines their treatment plan. This includes recommendations on specific antiviral medications and treatment duration.

The World Health Organization (WHO) recommends pan-genotypic direct-acting antivirals (DAAs) for chronic hepatitis C for adults, adolescents, and children. DAAs may cure most people with HCV, and pan-genotypic means that it can treat all genotypes. Examples of pan-genotypic DAA treatments include:

• Sofosbuvir/Velpatasvir (Epclusa)
• Sofosbuvir/Velpatasvir/Voxilaprevir (Vosevi)
• Glecaprevir/Pibrentasvir (Mayvret)

These medications usually come as pills. Treatment duration usually lasts 12–24 weeks, depending on whether the person has cirrhosis.

Doctors sometimes prescribe a medication called ribavirin alongside antivirals. Doctors will not prescribe ribavirin to pregnant people or their partners, as it can cause congenital abnormalities or miscarriage.

To evaluate response to treatment, experts assess sustained virological response (SVR). The goal of treatment is to achieve SVR, where the virus is undetectable in the blood for 12 weeks or more.

Find out more about the cure rate of hepatitis C.

A 2020 study showed that different hepatitis C genotypes respond differently to treatment. Genotypes 2 and 3 generally respond less successfully to treatment than genotypes 1 and 2.

Genotype 3 may pose some challenges, and this type is generally associated with insulin resistance and risk for cancer. Genotype 3 is especially hard to treat in people who have:

• cirrhosis
• decompensated liver disease, a life threatening condition
• previously tried treatment

People with genotypes 2 and 3 may need treatment for a longer period.

Besides pan-genotypic DAA regimens, certain combinations of antivirals may work well — or even better — depending on the person’s genotype. For example, Zepatier (elbasvir/grazoprevir) works well for genotypes 1 or 4.

A doctor will tailor treatment on an individual basis, considering other factors too, including disease progression, possibility for treatment resistance, and side effect profile, among others.

Learn more about how hepatitis genotypes affect treatment.

Hepatitis C has different genotypes, the most common being genotypes 1, 2, and 3.

All genotypes cause the same amount of liver damage. However, people with genotype 1, particularly subtype 1b, are at greater risk of developing liver cirrhosis than people with other genotypes. Doctors assess which genotype a person has through blood tests to check their DNA sequences and viral load in the blood.

The WHO recommends pan-genotypic direct-acting antivirals (DAAs) for chronic hepatitis C regardless of the genotype.

Generally, people have one genotype, but if someone has traveled between regions where different genotypes are more common, they may have exposure to various HCV genotypes, leading to a mixed infection. However, this is unlikely to affect a person’s treatment.