Way of transmission or infection of hepatitis C
Hepatitis C is an inflammation of the liver caused by the hepatitis C virus. Hepatitis C is mainly transmitted via blood. What matters is that the blood of one person with hepatitis C gets into another person's bloodstream. Unfortunately, it is not yet possible to vaccinate against hepatitis C, as no effective vaccine has yet been developed.
Which transmission routes are there?
Hepatitis C can be transmitted whenever blood from one infected person enters another's bloodstream. In the past, those affected were often infected through blood. The disease had not yet been researched at the time, so it was neither known nor tested for it. Nowadays, in countries with high hygiene standards, hepatitis C is rarely transmitted via blood. There are other ways of getting infected, for example when tattooing or piercing, if the needle used has not been cleaned sufficiently beforehand. Drug consumption also increases the risk of infection. Transmission is particularly likely if several people use the same injection set. Risky sexual practices that result in minor injuries can also be the cause of infection with hepatitis C. In contrast, hepatitis C cannot be transmitted through normal social interaction with other people. Shaking hands or sharing spaces such as the bathroom and kitchen will not result in transmission. Even insects cannot transmit the disease from one person to another with a bite.
Also read our topic: Hepatitis C.
Sexual transmission route
In order for hepatitis C to be passed from one person to the next, the infected person's blood must get into the other person's bloodstream. This is rather unlikely during normal sexual intercourse, as small wounds are necessary for the transmission. Practicing risky sexual preferences, on the other hand, increases the risk significantly, as it can lead to minor injuries more often. Anal intercourse is also one of the more risky practices. Infection with hepatitis C usually occurs when small bleeding occurs during unprotected sexual intercourse. Frequently changing partners also increases the risk of contracting hepatitis C. This is mainly because the likelihood of sexual contact with an infected person increases. Statistics show that about 5% of those infected with hepatitis C are infected through sexual intercourse. Of this, 2% of those affected were transmitted through heterosexual intercourse. In 3%, the transmission occurred during homosexual intercourse. Men are particularly affected when infected through homosexual intercourse.
Probability of transmission with sexual contact
The likelihood of transmission of hepatitis C during sexual intercourse is low, but should not be neglected. In the case of sexual contact without risky sexual practices, transmission usually does not take place. To be infected, the person who has not yet been infected must have blood contact with an infected person. This can especially happen with high-risk sexual preferences. The use of a condom is usually sufficient as a protective measure in such cases.
Prevention of sexual contact
An infected and a non-infected person must have blood contact for infection. Therefore, a condom is the most suitable means of preventing sexual hepatitis C transmission. In addition, the risk of contracting hepatitis C increases with the number of partners with whom someone has sexual contact. The group most frequently affected by sexual transmission of hepatitis C are men who have homosexual intercourse with alternating partners. Therefore, another preventive measure would be the careful choice of a steady sexual partner.
For more information on this topic, read: Pathways of transmission for hepatitis C.
Transmission via saliva / tear fluid / breast milk
Hepatitis C cannot be transmitted through saliva or tear fluid. Contact with these body fluids of an infected person is therefore not dangerous (in contrast to contact with blood or sexual contact). However, caution is advised if there are injuries to the oral mucosa, for example. This can cause small amounts of blood to enter the saliva. Infection is very unlikely, however, since both the uninfected and the infected person must have mucosal defects in order for blood contact to take place. Infected mothers can infect their children before or during birth. The risk of transmission is around 4%. Infection through breast milk has been and is discussed, but is extremely unlikely. So far, the breast milk of mothers infected with hepatitis C has been tested in several studies. The virus could not be detected in any of the samples, so transmission through breast milk is not considered possible. However, this fact has not been definitively proven, which is why no one hundred percent certainty can be given.
Probability of transmission of saliva / tears / breast milk
It is considered certain that hepatitis C cannot be transmitted through saliva or tear fluid. Therefore, one can assume a transmission probability of around 0%. When it comes to breast milk, the risk of transmission is still being discussed. A transmission has not yet been definitively ruled out, but no study has so far shown that hepatitis C viruses are present in breast milk. Therefore, based on the current state of knowledge, there is also a risk of transmission of almost 0% for infection through breast milk.
Prevention Via saliva / tears / breast milk
Since the transmission of the hepatitis C virus via saliva and tear fluid is not considered possible, no prevention is necessary here. Caution should only be exercised if blood is mixed in. In case of doubt, it is important to avoid contact with the body fluids mentioned. The same applies to the transmission of the virus through breast milk. Here, too, infection is extremely unlikely. If the mother has a very high viral load, it is still advisable to feed the infant with substitute milk.
Transmission via a blood transfusion
Until 1992, blood products were not tested for hepatitis C in Germany because the disease was still unknown and insufficiently researched. Anyone who received blood transfusions before 1992 has a very high risk of contracting hepatitis C. The risk of transmission has been minimized through newly introduced hygiene standards. Only in the case of a blood donation by a freshly infected person is a detection of the hepatitis C virus not always possible and therefore transmission is conceivable. In countries with different hygienic conditions in medical care, hepatitis C transmission through blood transfusions is not uncommon.
Also read our topic: Blood transfusion or causes of hepatitis C.
Probability of transmission through a blood transfusion
The probability of transmission of hepatitis C through blood transfusions in Germany is now around 1: 4 million. There are comparable rates in other industrial nations with similar hygienic conditions in medical care. In countries with lower hygienic standards, transmission through blood supplies is not uncommon. Exact figures on the transmission probabilities vary greatly from country to country.
Transmission in drug addiction
Drug addiction is one of the greatest risk factors for contracting hepatitis C. In many cases, syringes are needed by several people without the needle being disinfected and sterile cleaned in between. This makes the syringe an easy source of infection for many diseases. Hepatitis C is a commonly transmitted disease. The disease is now widespread among drug addicts (in 2011 this affected around 2/3 of drug addicts in Germany), so that transmission is becoming more and more likely. The highest infection rate was in Mexico in 2011, where the infection rate among drug addicts was 97%.
Transmission through dialysis
In most cases, dialysis is used as a kidney replacement procedure. Since the kidneys can no longer rid the blood of many toxins, blood is directed from the body into a dialysis machine. There it is cleaned by machine and then brought back into the body. Since the blood is “washed” during dialysis, transmission of hepatitis C through the dialysis machine is basically possible. In Germany around 4.7% of dialysis patients currently suffer from hepatitis C. Some of them have contracted dialysis, but the greater part has become dialysis due to hepatitis C. How large and what proportion of the affected people is has not been precisely investigated and is therefore unknown.
Is infection possible despite vaccination?
A vaccine that works against hepatitis C is not yet available. However, vaccination against hepatitis A and vaccination against hepatitis B can be done. Since the pathogens are different viruses, a hepatitis A and / or B vaccination does not automatically protect against infection with hepatitis C. The exact response of the body's immune system to the hepatitis C virus has not yet been sufficiently researched, which is why the development of one Vaccine has not yet succeeded. In 2014 there were tests in which the first short-term immunizations against the virus could be detected. However, the vaccine has not yet proven successful.
Read more on the topic: Vaccination against hepatitis C
What influence does the viral load have on transmission?
The viral load describes the number of hepatitis C viruses that are in one milliliter of blood. The greater this number, the more likely it is that the virus will be passed on to other people. For this reason, mothers with a high viral load, for example, are recommended to feed their babies with replacement milk as a precaution. However, it has not yet been possible to quantify a precise relationship between viral load and the risk of transmission. However, it is considered certain that there is a connection. In contrast, viral load and the course of the disease are not necessarily related.