The infection
Hepatitis C is caused by a virus that infects the liver and becomes chronic in roughly two thirds to three quarters of cases. It is primarily blood-borne: sexual transmission is low among stable heterosexual couples but substantially higher where practices involve blood, and notably among men who have sex with men living with HIV. Direct-acting antivirals transformed its outlook within a few years.
Key facts
| Organism | Hepatitis C virus, an RNA virus |
|---|---|
| Incubation | Two weeks to six months |
| Sexual transmission | Low in the general population, significant where blood is involved |
| Testing from | Antibodies at four to ten weeks; PCR detects earlier |
| Becomes chronic | About 70% |
| Curable | Yes, over 95% with eight to twelve weeks of treatment |
| Vaccine | None |
How it is transmitted
The main route is contact with infected blood: sharing injecting or snorting equipment, poorly sterilised tattoo or piercing equipment, medical procedures in inadequate hygiene conditions. Sexual transmission exists but is marginal in heterosexual sex without blood exposure. It becomes significant with traumatic sex, mucosal damage, menstruation, concurrent infections, or in a chemsex context.
Symptoms
Acute infection is silent in the great majority of cases; when it declares itself, it is through fatigue, nausea and occasionally jaundice. Chronic infection is symptomless for years, with at most a fatigue attributed to something else. It is usually found on a routine blood test showing raised liver enzymes, or through targeted screening.
Testing
Testing is a two-step process: an antibody test, then, if positive, a PCR to look for the virus itself. The second step is essential, because antibodies persist after cure: someone who has cleared the infection stays antibody-positive for life. Rapid point-of-care tests exist and are likewise confirmed by PCR.
Treatment
Treatment is with direct-acting antivirals taken by mouth for eight to twelve weeks, with cure rates above 95% and very few side effects. Cure is confirmed by a negative PCR twelve weeks after finishing. It is permanent, but confers no protection against a new infection: reinfection happens and is documented.
If left untreated
Untreated chronic infection progresses to fibrosis, then cirrhosis in a proportion of people after twenty to thirty years, with a risk of liver cancer. Alcohol, excess weight and co-infection with HIV or hepatitis B all accelerate it. Once cirrhosis has developed, clearing the virus remains beneficial but liver surveillance must continue.
Prevention
- There is no vaccine: prevention rests entirely on avoiding contact with blood.
- Never share injecting or snorting equipment, or any object that may carry blood.
- Check hygiene standards and single-use equipment before a tattoo or piercing.
- Use gloves and condoms for practices involving blood, and change equipment between partners.
After a diagnosis
- Have liver function and fibrosis assessed before starting treatment.
- Check the PCR twelve weeks after finishing: that is what confirms cure.
- Get vaccinated against hepatitis A and B if you have not been.
- Continue testing after cure if exposure continues: there is no protective immunity.
Worth remembering
A positive antibody test does not mean you are still infected. Only the PCR distinguishes active from cleared infection — insist on that second step before drawing any conclusion.
A little history
After the discovery of the hepatitis A and B viruses, there remained in the 1970s post-transfusion hepatitis that was neither one nor the other: Harvey Alter named it "non-A, non-B hepatitis" in 1975. The virus resisted every attempt at isolation for fourteen years. In 1989 Qui-Lim Choo, George Kuo and Michael Houghton at Chiron identified it by a new method, cloning its genetic material directly from the blood of an infected chimpanzee. The screening test followed in 1990, and the transfusion risk collapsed within two years. Alter, Houghton and Charles Rice received the Nobel Prize in Medicine in 2020.
Treatment was long interferon, alone and then with ribavirin: a year of injections with gruelling side effects for fewer than one cure in two. The revolution came with direct-acting antivirals: sofosbuvir, approved at the end of 2013, and its successors cure more than 95% of patients in eight to twelve weeks of tablets, without interferon. Their launch price — $84,000 per course in the United States — set off a worldwide debate on drug prices, before falling with generics.
Hepatitis C thus became the first chronic viral infection that can be cured. The WHO has set the goal of eliminating it as a public health problem by 2030; Egypt, long the most affected country in the world, screened more than 60 million people in 2018-2019 and treated the carriers, showing it can be done at scale.
How this differs between countries
Treatment cures more than 95% of cases everywhere. The real difference is who can get it, and who is diagnosed at all.
- Access to antivirals. Initially restricted to advanced disease in most wealthy countries, then opened to everyone — but at very different dates.
- Generics. Voluntary licences allow low-cost generic production for much of the low and middle income world; there the bottleneck is diagnosis, not the medicine.
- Elimination programmes. A few countries have run mass screening campaigns that transformed their epidemics within a few years, demonstrating that elimination is technically achievable.
- Harm reduction. Access to sterile needles and opioid substitution treatment is decisive for interrupting transmission: extensive in some countries, prohibited or marginal in others.
- Injection safety. In several countries, reuse of equipment in informal healthcare settings remains a major source of transmission.