What is hepatitis C?

Hepatitis C is caused by the hepatitis C virus (HCV), which leads to inflammation of liver cells (hepatitis). If not diagnosed and treated, it can progress to chronic forms (cirrhosis) and liver cancer. It is estimated that about 3% of the world population—over 170 million people—are chronic carriers of hepatitis C. It is currently one of the main indications for liver transplantation in developed countries and is responsible for 60% of chronic liver diseases and half of liver cancer cases in Western countries.

Types

Hepatitis C is caused by an RNA-type virus (genetic material), and there are several genotypes (variations) of this virus—six of which are the most important (1 to 6). These genotypes are further subdivided into more than 50 subtypes (1a, 1b, 2a, etc.). Genotypes can differ by 30% to 50% in their RNA. This classification is important because each subtype has its own characteristics in terms of aggressiveness and response to treatment.

Transmission

HCV is mainly transmitted through contaminated blood. In Brazil, the incidence of hepatitis C among blood donors is about 1.2%, with some regional differences. The infection can also be transmitted through sexual contact and perinatally (from mother to child, especially during childbirth), as well as through contaminated instruments such as nail clippers, tattooing, and piercing (the hepatitis C virus can survive from 16 hours to 4 days in external environments).

Although recent reports have shown the presence of the virus in other secretions (milk, saliva, urine, and semen), the viral load appears to be too low to cause infection, and there is no evidence suggesting transmission through these routes. Sexual transmission is highly debated. It is true that hepatitis C is much less sexually transmitted than hepatitis B. Among stable partners of infected individuals, the prevalence of sexual transmission is only 0.4% to 3%, and in many of these cases, other associated risk factors are often present. On the other hand, among people with no known risk factors, 2% to 12% have hepatitis C (sporadic transmission).

Currently, there is no data indicating the need for condom use in stable relationships where one partner has hepatitis C. Other risk factors are considered more significant, such as: intravenous drug use, recipients of blood, blood products, or organ transplants before 1992, patients on hemodialysis, children of mothers with hepatitis C, and healthcare professionals exposed to contaminated blood.

Diagnosis

Diagnosis is often made only through blood donation screening, routine check-ups, or when symptoms of liver disease appear in the advanced stage of cirrhosis. The main diagnostic method for hepatitis C remains serology for anti-HCV (blood test), with the preferred method being the detection of viral RNA in the blood, which can be found 7 to 21 days after infection (PCR).

After confirming HCV infection, genotyping (identification of the subtype) is usually requested, which is important for treatment decisions. When the severity of the disease cannot be accurately determined by non-invasive methods (blood tests or liver elastography), a liver biopsy may be necessary.

It is recommended that individuals with any of the previously mentioned risk factors—such as transfusions, sharing needles or straws for injectable or inhaled drug use, tattoos with non-disposable materials or ink, especially before 1994—undergo a blood test (hepatitis C serology).

Treatment

Only 15% to 30% of people infected with the hepatitis C virus recover spontaneously, while 70% to 85% progress to chronic hepatitis. If viremia persists, liver damage may progress to cirrhosis (20% to 30% of chronic hepatitis C carriers develop cirrhosis after 10 to 20 years of infection). Other factors such as male gender, hemochromatosis (iron accumulation in the liver), alcohol consumption, co-infection with hepatitis B or HIV, use of immunosuppressants (after transplants, treatment of autoimmune diseases, or certain cancers), and possibly hepatic steatosis (fat accumulation in the liver) can accelerate disease progression.

Unlike hepatitis A and B, hepatitis C usually develops as a chronic and slow disease, with most cases (90%) being asymptomatic or presenting very nonspecific symptoms such as lethargy, muscle and joint pain, fatigue, nausea, or discomfort in the right upper abdomen. The incubation period (from contact with the virus to the development of acute hepatitis) is 15 to 60 days, but transmission can occur even before that. The most common symptoms are jaundice (yellowing of the eyes and skin), fatigue, fever, nausea, vomiting, and discomfort in the upper right side of the abdomen, usually 2–12 weeks after exposure and lasting 2–12 weeks. In addition to symptoms directly related to hepatitis, the virus can trigger other diseases through immune system stimulation: thyroid problems (hypothyroidism, autoimmune thyroiditis), kidney issues (glomerulonephritis), skin conditions (porphyria, vitiligo, lichen planus), among others.

Hepatitis C is now considered curable. After diagnosis and viral genotyping, the first step is to consult a specialist (hepatologist), who will assess the degree of liver damage and recommend appropriate follow-up (as the patient may already have cirrhosis or cancer) and the best treatment option.

Many of the new oral medications, known as antivirals, can be used for shorter periods and with fewer side effects, and several are provided by the Brazilian public health system (SUS). Available medications include: Daklinza™ (daclatasvir), Olysio® (simeprevir sodium), Sovaldi® (sofosbuvir), Viekira Pak (ombitasvir/veruprevir/ritonavir + dasabuvir), Zepatier® (grazoprevir and elbasvir), and Harvoni® (sofosbuvir and ledipasvir).

It is important to note that there is no vaccine for hepatitis C. Advanced cases that progress to decompensated cirrhosis or liver cancer should be evaluated for liver transplantation.

By Einstein Editorial Board