Pathogens and transmission
Hepatitis C is a liver inflammation caused by an infection with the hepatitis C virus (HCV). As the pathogen is primarily transmitted through the blood of an infected person, the risk of an infection lies primarily in the sharing of syringes, medical procedures with insufficiently sterilised instruments, the use of non-sterile instruments for tattoos or piercings or injuries with the latter. Blood transfusions in countries where donor blood is not tested for antibodies can also be a source of infection.
Sexual transmission of the virus is very rare, as this route of transmission is very ineffective for HCV. In HIV-positive men who have sex with men, in the last 20 years HCV infections have been detected that have taken place during sexual encounters. On closer inspection, however, these also appear to be infections via blood contact, and there are fewer than 20 cases per year. Transmission from mother to child during labour is possible but rare.
Clinical picture
In 75 percent of cases of people newly infected with the hepatitis C virus the infection progresses with no symptoms. In the remaining 25 percent of cases, people develop symptoms six to nine weeks (up to a maximum of six months) after having been infected. Symptoms can include loss of appetite, abdominal pain, nausea and vomiting. Other possible symptoms are fever and joint pain. 5 to 10 percent of the infected persons also develop jaundice. 20 to 30 percent of infected persons recover from the infection without treatment after six months. However, this does not protect them against Hepatitis C and they may therefore become infected again.
Often chronic progress but can be cured
70 to 80 percent of infected patients do not recover spontaneously from the virus within six months and develop a chronic infection (the virus remains in the liver). People who are chronically infected mostly live for years without any symptoms. In ca. 5 to 30 percent of cases, patients develop liver cirrhosis after several decades (scarring of the liver tissue). These patients have an increased risk of developing hepatocellular carcinoma.
An HCV infection can be treated with antiviral medication if it does not heal spontaneously but becomes chronic. In over 90 percent of cases, patients treated can be cured, but this does not protect them from being infected by the virus again.
Frequency and distribution
In Switzerland, 0.1 to 0.4 percent of the population are chronically infected with the hepatitis C virus, depending on the estimate, and around 1 percent on average worldwide. The number of reports of people with acute hepatitis C in Switzerland has been declining for 20 years (between 10 and 30 cases per year in the last five years). Of these cases, three-quarters are men and more than half are between 30 and 49 years old. In the case of hepatitis C, the identification of transmission routes is often difficult because the time of infection is in most cases unknown. Accordingly, the transmission route is unknown in around three-quarters of cases (2020/21). As for the remaining quarter with a known transmission route, the majority of newly diagnosed infections can be traced back to intravenous drug use.
Prevention
There is no vaccination against hepatitis C. Protection against an infection consists primarily in avoiding contact of blood from another person with your own body through skin lesions, wounds or mucous membranes. In particular, syringes should not be shared and all practices involving pricks or injuries with instruments that are badly or not sterilised at all should be avoided.
Hepatitis C can also be transmitted through hazardous sex, primarily through contact of blood and mucous membranes. This is why it is also important to avoid contact with any blood during sexual intercourse.