Hepatitis is an inflammation of the liver, most often caused by infection with a virus, but sometimes by alcoholism, or by drug or chemical poisoning.

Symptoms vary a lot from person to person and depend on the cause of the hepatitis. Some types of hepatitis cause part of the liver to be destroyed outright.

The majority of hepatitis resolves spontaneously, without leaving any sequelae. Sometimes the disease persists for several months. When it lasts more than 6 months, it is considered chronic. When the liver is seriously damaged, a transplant of this organ may be the only solution.

Types

Hepatitis can be grouped into 2 main categories:

• the viral hepatitis, caused by virus infection. In developed countries, hepatitis A, B and C viruses cause about 90% of acute hepatitis cases. Hepatitis D, E and G viruses are also responsible for hepatitis.
• the non-viral hepatitis, mainly caused by the ingestion of products toxic to the liver (alcohol, toxic chemicals, etc.). Non-viral hepatitis can also be the result of diseases affecting the liver, such as fatty liver (fatty liver) and autoimmune hepatitis (a chronic inflammatory hepatitis of obscure origin, which is characterized by the production of autoantibodies).

Frequency of hepatitis

In Canada,Hepatitis C is the most common viral hepatitis: each year, it affects about 45 in 100 people¹. As for hepatitis B, it affects about 3 in 100 Canadians, and hepatitis A, 000 in 1,5^1,42.

Viral hepatitis is much more common in non-industrialized countries. THE’hepatitis A is endemic in Africa, some countries in South America and Asia². The same is true for hepatitis B. Indeed, in most countries of sub-Saharan Africa and Asia, where 8% to 10% of the population are carriers of theHepatitis B, it is one of the main causes of death in adults (from liver cancer or cirrhosis). Almost 3% of the world’s population is infected with the virusHepatitis C. In Africa, the prevalence of this infection is the highest in the world: it exceeds 5%⁴.

Public health authorities are struggling to tackle viral hepatitis, which often go unnoticed for years. Before a diagnosis is made, the infection may not only have caused serious damage to the body, but also spread to other people.

Contraction modes

• Hepatitis A. It is the least serious of the viral hepatitis. Usually the body fights it within a few weeks and remains immune for life. This means that antibodies against the virus are present, but the virus itself is no longer there. The hepatitis A virus is spread by ingestion ofwater orcontaminated food. It can be found in the stool of an infected person and contaminate the food, water or hands of another person. Raw or undercooked foods are the most likely to transmit the infection. The virus can also be transmitted by seafood harvested from areas where untreated sewage is discharged. The risk of transmission is high in countries with poor hygienic conditions. In these countries, almost all children have already been infected with the virus. A vaccine protects against it.
• Hepatitis B. This is the type of hepatitis most frequently in the world, and also the most deadly. The hepatitis B virus is spread around the time of sex (semen and other body fluids contain it) and by the blood. It is 50 to 100 times more infectious than the AIDS virus³. Exchanging contaminated syringes can cause transmission. The vast majority of people who are infected manage to completely fight off the infection. About 5% remain chronically infected and are said to be “carriers” of the virus. Carriers have no symptoms, but they are at high risk of developing liver cirrhosis or liver cancer, which are life-threatening illnesses. A surrogate mother can pass the virus to her baby during childbirth. A vaccine has been offered since 1982.
• Hepatitis C. Hepatitis C is the form of viral hepatitis the most insidiousbecause it is caused by a very resistant virus. Up to 80% of hepatitis C virus infections become chronic. The identification of the latter is relatively recent: it dates from 1989. The virus is most often transmitted by direct contact with contaminated human blood : mainly by exchanging syringes used for injecting drugs, by transfusion of blood that has not been screened, and by the reuse of unsterile needles and syringes. More rarely, it is contracted during unprotected sex with infected people, especially if blood is exchanged (menstruation, injuries in the genital or anal passages). It is the number one cause of liver transplantation. There is no vaccine to protect against it.
• Toxic hepatitis. It is most often caused by alcohol abuse or the consumption of pharmaceuticals. Ingestion of champignons inedible, exposure to chemical products (in the workplace, for example) as well as the ingestion of natural health products or poisonous plants for the liver (like plants of the Aristolochiaceae family, because of the aristolochic acid they contain, and comfrey, because of the pyrrolizidines it contains) can also cause toxic hepatitis. Depending on the substance ingested, toxic hepatitis can develop hours, days or months after exposure. Usually, the symptoms subside when one stops being exposed to the harmful substance. However, one can suffer permanent damage to the liver and suffer, for example, from cirrhosis.

Possible complications

Hepatitis that is not diagnosed in time or that is poorly treated can lead to very serious complications.

• Chronic hepatitis. This is the complication the most frequent. Hepatitis is said to be chronic if it is not cured after 6 months. In 75% of cases, it is the result of hepatitis B or C. Chronic hepatitis treated adequately is usually cured within one to three years.
• Cirrhosis. Cirrhosis is an excessive production of “scars” in the liver, formed as a result of repeated attacks (by toxins, by viruses, etc.). These “fibrous barriers” end up hindering the free flow of blood in the organ. 20% to 25% of chronic hepatitis progress to cirrhosis if the treatment does not work fully or if it is not well followed.
• Liver cancer. It is the ultimate complication of cirrhosis. However, it should be noted that liver cancer can also result from cancer located in another organ that spreads to the liver by metastasis. Hepatitis B and C, as well as toxic hepatitis caused by excessive consumption ofalcohol are most likely to progress to cancer.
• Fulminant hepatitis. Very rare, fulminant hepatitis is characterized by a major failure of the liver, which can no longer perform its functions. Massive destruction of liver tissue occurs and organ transplantation is required. It mostly occurs in people with hepatitis B or toxic hepatitis. For about 1 in 4 people, it is fatal in the short term.