Natural history of hepatitis C

As with HIV, there are similar terms to describe the natural history of HCV infection.

Acute infection (0-6 months)

Acute infection refers to the first six months after hepatitis C (HCV) infection.

Unless it causes symptoms – and about 80% people do not have symptoms – HCV is rarely diagnosed in acute infection.

Symptoms, when they occur, include fever, fatigue, abdominal pain, nausea, vomiting, dark urine, and jaundice (yellowed skin and eyes).

However, because HIV treatment involves checking for liver function, higher liver enzyme levels has helped diagnose acute HCV infection in HIV-positive people.

In the first few months after HCV infection, some people clear the virus without any treatment. This occurs in perhaps up to 20% of HIV-positive people. This is called 'spontaneous clearance' and is more common if:

You have symptoms during acute HCV
You are a female
You are under 40 years old

HIV-positive people are only half as likely to spontaneously clear HCV. People of African decent are less likely to clear hepatitis C than Caucasians. The reasons for these differences are unclear.

People who have cleared the virus without treatment are no longer infected with HCV. They may test HCV-positive using with an antibody test, but the virus is not detectable in their blood.

If HCV does not clear spontaneously, some people choose HCV treatment during acute infection. This is because there are higher success rates at this stage. It is important to discuss the risks and benefits of treating acute HCV with your doctor.

Chronic infection (6+ months)

Chronic infection refers to any time after acute infection. This is usually from 6 months after infection.

There is a wide range of outcomes from chronic hepatitis C. In HIV-negative people, hepatitis C (HCV) progresses very slowly, usually over decades. There have been reports of HCV progressing more quickly in HIV-positive gay men.

Whatever the timescale, some people will never have significant liver damage or symptoms, while others may develop mild-to moderate liver scarring (fibrosis), and experience symptoms such as fatigue, depression and confusion.

HCV can affect other areas of the body.

There seems to be no clear relationship between the degree of liver damage and the experience of symptoms.

Hepatitis C can contribute to a build-up of fat in liver cells called steatosis (or fatty liver), which worsens liver damage and makes HCV harder to treat.

Fatty liver is most common in people with HCV genotype 3.
In people with HCV genotype 1 fatty liver is more likely among people who are overweight, have insulin resistance or diabetes, who have a heavy alcohol intake and who have liver inflammation.

In people with HIV/HCV coinfection, fatty liver usually indicates more serious liver scarring. It is linked with several factors, including use of some HIV drugs (especially d4T and ddI), low levels of HDL ('good' cholesterol), being overweight and having lipodystrophy.

About 20-30% of people with chronic, untreated HCV will progress to cirrhosis (serious liver scarring). Even then, the liver can still function. When a cirrhotic liver can 'compensate' for the damage this is called compensated cirrhosis.

When the liver is too damaged to function properly, this is referred to as decompensated cirrhosis or end stage liver disease.

End stage liver disease

If compensated cirrhosis progresses to decompensated cirrhosis, a liver transplant is required.

Although it is a serious operation, successful liver transplants have been carried out in people with coinfection.

Each year, 1-5% of people with cirrhosis develop hepatocellular carcinoma (HCC, liver cancer).

This can also be successfully treated, especially if it is caught early.

Factors that accelerate hepatitis C progression

HIV coinfection
Alcohol intake, especially more than 50 grams/day
Aging
Duration of infection
Older at time of infection (over 40 years of age)
Hepatitis B coinfection
Hepatitis C may progress faster in men than women