World Hepatitis Day, a multi-faceted disease

What is the commonality between viruses, alcohol and drugs? All can be the cause of hepatitis. But regardless of the mode of transmission, hepatitis always causes inflammation in the liver that, if left untreated, can be fatal. Alcohol abuse or the use of certain medications may be responsible, but of all hepatitis, the most widespread are by far those caused by viruses. In 2015, viral hepatitis was the cause of nearly 1.4 million deaths worldwide, according to the World Health Organization (WHO).

But how are these viruses doing it? It is enough to come into contact with a contaminated body (blood, sperm, water, food, etc.) so that the virus infects our organism. Then the viruses "enter the liver cells, hepatocytes, resulting in an immune reaction that destroys the virus but also the infected hepatocyte," says Dr. Dominique Thabut, a hepatologist at the hospital Pitié-Salpêtrière and member of the French Association for the Study of the Liver (AFEF). This is what causes inflammation of the liver. And if it is not treated in time, this information can eventually lead to cirrhosis or cancer of the liver.

There are five types of hepatitis viruses: A, B, C, D and E , the most common of which are strains B and C, responsible for 96% of deaths. By itself, hepatitis B affects 1.6% of the European population, or 15 million people, and 14 million Europeans are affected by hepatitis C. While some viral infections such as HIV or tuberculosis are in This is not the case with hepatitis, which has caused an additional 22% of deaths since the 2000s.

Despite this, hepatitis is still underdiagnosed in the world. "Only 9% of HBV infections and 20% of HCV infections were diagnosed in 2015," warned WHO last year. A bad score that is explained by the fact that hepatitis is a disease that can remain asymptomatic for a long time. But when the disease manifests itself, the symptoms are very recognizable: yellowing of the skin and eyes, dark urine, fatigue, nausea, vomiting and abdominal pain

What are the characteristics of the different hepatitis viruses? 19659007] ● Hepatitis A

The hepatitis A virus is present in the stool of infected persons. It is usually spread by water or contaminated food, which can cause rapid outbreaks. "In many cases, the manifestations of the infection are benign and the subject heals and acquires immunity. But the infection can also be serious or even life-threatening, "says WHO. A vaccine exists.

● Hepatitis B

Hepatitis B is a major public health problem: WHO estimates that 257 million people are infected with this virus. The disease is extremely contagious: "the hepatitis B virus is 50 to 100 times more infectious than that of AIDS," says the Institut Pasteur. The prognosis is very unfavorable: about a quarter of cases evolve in cirrhosis. In addition, three-quarters of hepatocellular carcinomas – the most common liver cancer – are caused by this virus.

The virus can be transmitted at birth: "It is either a vertical transmission of the mother to child during childbirth, either transmission via the placenta when the pregnant woman has a high level of HBV replication, or transmission between young children when they are raised together "Says the Collegiate University of Hepatogastroenterology. Exposure to contaminated body fluids such as blood or semen is also risky. Sexual intercourse, toiletry sharing or contact with the blood (medical procedures, or any contact with unsterilized syringes) can therefore be the source of contamination. Since 1982, a vaccine is available.

● Hepatitis C

As with hepatitis B, transmission can occur through badual intercourse or contact with tainted blood. "In France, between 150,000 and 200,000 people would live with HCV," says the Collegiate University in Hepato-Gastroenterology. In most patients, the infection is chronic and can progress to cirrhosis in 10 to 20% of cases. Hepatitis C is the only hepatic virus strain for which there is no vaccine, but antiviral treatment is 100% effective, according to Dr. Dominique Thabut, a hepatologist at the Pitié Salpêtrière Hospital. in Paris. Available since 2014, "this new treatment for hepatitis C is part of the upsetting progress of medicine in recent years," she says.

● Hepatitis D

The virus D depends on the virus B for its multiplication: there can be no infection with the hepatitis D virus without contamination by the virus B. "The co-infection with HDV and HBV can aggravate the disease and darken the prognosis", details WHO. "At least 5% of people with chronic HBV infection are also infected with HDV," says the organization. As with hepatitis B, transmission occurs either badually or in contact with contaminated blood. Transmission from mother to child is possible, but rare. Vaccination against hepatitis B also protects against D. virus

● Hepatitis E

Hepatitis E is spread by fecal-oral route, that is to say via the stool, which then contaminates the water. In industrialized countries, it is transmitted rather through the ingestion of contaminated meat. The virus can infect humans and some strains also affect animals, including pigs, wild boars and fallow deer. A vaccine is currently available, but only in China.

How to protect yourself?

Preventing cases of viral hepatitis requires some hygienic precautions, such as washing hands after using the toilet or contacting animals, and before preparing meals ; cook raw meats thoroughly and clean used utensils, and do not consume untreated water. To avoid hepatitis B, C and D, it is important to protect yourself by using a condom during intercourse and to avoid contact with objects soiled with blood.