What is hepatitis C ?
Hepatitis C is an infectious disease which predominantly affects the liver and is caused by the hepatitis C virus (HCV). This form of hepatitis is discovered only in the late eighties; until then it was referred to as' non A non B hepatitis. Infection occurred at that time, usually on by blood transfusions. There is no vaccine against hepatitis C.
Symptoms of hepatitis C
A hepatitis C infection proceeds in the beginning is usually asymptomatic. The infection is in the majority of cases (70%) unnoticed over in a chronic form. Approximately 20-30% of people with the chronic form develops liver damage (scarring) and this gets around 2-5% per year liver cancer. Some people get only 20 or 30 years after infection symptoms when the liver is already affected.
Hepatitis C transmission
The hepatitis C virus is transmitted through the blood. It is usually transmitted through:
- intravenous drug use by sharing needles;
- healthcare through the reuse or inadequate sterilization of medical instruments;
- In some countries, HCV is transmitted through transfusion of non-screened blood and blood products;
- HCV can also be sexually transmitted, and can be passed from an infected mother to her baby; However, these are less common;
- tattoos / body piercing, acupuncture, ritual and other invasive procedures involving non-sterile equipment is used.
Because since the early 90s in Belgium and the Netherlands blood donors are screened for the presence of hepatitis C virus antibodies, the risk of infection after blood transfusion has declined significantly.
Virology
The hepatitis C virus is a small, single-stranded positive RNA virus. It belongs to the genus of the Hepacivirus within the Flaviviridae family. There are seven different types of virus (the virus genotype 1-7). These genotypes are further divided into subtypes.
Hepatitis C diagnosis
Since acute HCV infection is usually asymptomatic, it is an early diagnosis of HCV infection rare. The patients who are chronically infected, the infection is often not diagnosed unless there is severe liver damage has developed.
HCV infection is diagnosed in two steps:
- Screening for anti-HCV antibodies with a serological test diagnose people who have been infected with the virus.
- If the test is positive for anti-HCV antibodies, a nucleic acid test for HCV-RNA will be needed to confirm the chronic HCV infection, because about 15-45% of patients with HCV clear the infection without treatment by a strong immune response. Although these patients are no longer contaminated, they will still respond positively to the presence of anti-HCV antibodies.
Moreover, a genotyping test to be performed to identify the genotype of the hepatitis C strain. However, the success rate of treatment depends on the genotype of the HCV. The degree of liver damage and the virus genotype can be used to capture the choice of treatment and the follow-up of the infectious disease.
Hepatitis C treatment
In general, the treatment is recommended for patients with a proven HCV infection, which are observed signs of liver disease. Since 2000, the standard treatment for hepatitis C consists of a combination of PEG-interferon with ribavirin. Ribavirin is an antiviral drug that enhances the effect of alpha-interferon and the multiplication of stopping the virus. The treatment of alpha-interferon and ribavirin capsules it takes (depending on the virus genotype) about 24-48 weeks. For genotypes 2 and 3, the success rate 70-80% after 24 weeks for genotypes 1 and 4, this 45-70% after 48 weeks. The response to treatment is monitored by the presence of virus particles in the blood to follow (viral load assay).
When the virus after 24 weeks, however, not enough, it has disappeared from the body (or even not at all has been reduced), then there is a so-called non-responder. This is a patient in whom the virus is not (or hardly) is responsive to the medication. In such a case, the treatment is futile and will be stopped.
New HCV protease inhibitors (Telaprevir and Boceprevir) were approved recently. Since they may give rise to resistance, they are only used in combination with other treatments. These new molecules increase the success rate of treatment for genotypes 1, 4, 5 and 6.
Since 2014, a behandling with sofosbuvir in a combination therapy of choice for all genotypes.
Hepatitis C epidemiology
Worldwide contribute approximately 150 to 200 million people a chronic form of hepatitis C infection. 350,000 to 500,000 patients die annually from hepatitis C-related liver diseases.
Although the Netherlands does not have very high numbers are concerned, approximately 60,000 people are infected, many of them without knowing it.
Epidemiological data for Belgium
The seroprevalence of HCV in the Belgian population was estimated in 1993-94 at 0.87%. During a subsequent prevalence study conducted in 2003 with a saliva test prevalence by 0.12% was measured.
Based on the number of reported cases in the network of sentinel laboratories and the number of performed genotyping HCV is estimated the annual incidence in 1500 (13.6 / 100,000). The distribution according to the regions are as follows: 45% in Flanders, 35% in Wallonia and 19% in Brussels. Despite increased screening for women aged 20-39 years there is a higher prevalence (M: F 1.06: 1) of HCV infected men with median age 45-49 years.
Staff from the health sector showed a lower seroprevalence than in the general population and therefore the nursing staff is not at increased risk.
The distribution of the genotypes in intravenous drug users was as follows: 48.7% genotype 1, followed by 41.2% genotype 3, genotype 4, and 8.8% 1.4% 2 genotype.