How It Is Spread
The main way hepatitis C virus (HCV) is spread is through contact with the blood of an infected person, such as via contaminated intravenous (IV) needles. Although less common, it can also be spread through shared razors and toothbrushes, contaminated piercing or tattooing tools, and during sex.
According to the US Centers for Disease Control and Prevention (CDC), those at increased risk for HCV infection include IV drug users, even if they only tried it once years ago; people who are HIV positive, those on chronic hemodialysis and recipients of blood transfusions or organ transplants before July 1992. Healthcare workers who could inadvertently receive a needle stick from a patient with HCV and babies born to mothers who are HCV positive also have an elevated risk.
The CDC estimates that up to 90% of people with hemophilia who used clotting factor prior to 1987 were exposed to HCV through contaminated products.
The CDC estimates that 3.2 million people in the US are chronically infected with HCV, with the highest incidence now appearing in Baby Boomers born from 1945-1965. Most patients are asymptomatic. However, symptoms can develop within the first 10 to 24 weeks after exposure. They can include fatigue, abdominal pain, loss of appetite, dark urine, clay-colored stools, nausea and vomiting, and jaundice.
Up to 25% of people spontaneously clear the virus, but the rest experience chronic HCV infection, which progresses slowly. If untreated, chronic HCV infection can lead to cirrhosis (scarring) of the liver or liver cancer decades later. HCV is the leading cause of liver transplants in the US, according to the CDC.
Testing and Treatment
Testing is recommended for high-risk groups, according to the CDC. It includes screening tests for antibody to HCV. If anti-HCV antibody is detected, other tests can then determine the amount of virus in the bloodstream and the genotype, or strain, of the virus. There are at least six genotypes, with HCV 1 being the most common, and 50 subtypes. The standard of care for HCV is a weekly injection of pegylated interferon and ribavirin, a pill taken twice daily, for up to 48 weeks. However, studies have shown that only 50% of patients with HCV 1 who are on the regimen clear the virus, achieving sustained virological response (SVR), an indicator that the person is cured. Many people have to stop treatment early because the side effects are so severe.
In 2011, the FDA approved two protease inhibitors, the first new HCV drugs in a decade. They are added to the standard of care and prevent HCV from replicating. Pharmaceutical companies are testing other drugs, such as polymerase inhibitors, in clinical trials to find regimens that do not require interferon, that can be taken for shorter periods, such as 12 weeks, and that combine multiple medications in one pill.
In 2013, the FDA approved two new drugs to treat HCV: sofosbuvir, a polymerase inhibitor used in combination with ribavirin or with interferon/ribavirin to treat patients with genotypes 1-4, and simeprevir, a protease inhibitor used in combination with interferon/ribavirin to treat HCV 1.
A year later, in October 2014, the FDA announced the first complete treatment for HCV contained in a once daily pill. Harvoni™, a combination of ledipasvir, an NS5A inhibitor, and sofosbuvir, a polymerase inhibitor, is manufactured by Gilead. It eliminates the need for interferon/ribavirin. It is prescribed for patients with HCV 1. In a clinical trial of treatment-experienced patients without cirrhosis 94% achieved SVR in 12 weeks; 99% of those with cirrhosis achieved SVR in 24 weeks.
Prevention and Vaccination
To prevent the spread of HCV, good hygiene techniques should be followed, such as wearing latex gloves when handling blood products, and avoiding sharing IV needles, razors and toothbrushes. Those with HCV are cautioned to avoid alcohol, which can contribute to cirrhosis and end stage liver disease.
There is no vaccine to prevent HCV, but in 2014 at least one pharmaceutical company plans to test an HCV vaccine in chronically infected patients in the US who have not cleared the virus while on previous therapies.