Seven facts about hepatitis

Affectionate killer

Maria Bogdanovskaya, Mednovosti

Fact #1
There are more than eight types of hepatitisHepatitis is not always an infectious disease.

A person can get hepatitis without getting infected from anyone. The fact is that, in addition to viral, there is autoimmune and toxic hepatitis. In the first case, the liver is attacked by the human immune system (the reasons for such aggression are unknown). With toxic hepatitis, the liver is affected by certain medications (an overdose of paracetamol, amoxicillin and potassium clavulanate), industrial chemicals and alcohol. The liver of 20 percent of alcoholics sooner or later comes under attack. As a result of these effects, inflammation of the liver occurs.

But viral hepatitis is still the most common. There are at least six different viruses that cause hepatitis (A, B, C, D, E, G). They are very different in nature, and the diseases that arise as a result of infection with each of them are also different. The most dangerous are hepatitis B and C, which lead to the development of severe forms of chronic hepatitis. The hepatitis D virus also leads to this, but it is dangerous only if a person is already infected with the hepatitis B virus. Viruses A and E are less dangerous because they cause only acute hepatitis. The hepatitis G virus was discovered relatively recently, and the scientific community is still arguing about whether it is the cause of hepatitis.

Fact # 2
Hepatitis B and C are infected not only by drug addicts2 billion people worldwide are infected with hepatitis B, 400 million of them suffer from chronic hepatitis.

The problem is that many infected people do not know about their own status, and therefore spread the virus further. The World Health Organization estimates that about 3 percent of the world's population is infected with hepatitis C. Up to 85 percent of acute infections turn into chronic hepatitis.

Hepatitis B and C are infected not only by drug addicts. Blood transfusions, a manicure at the salon and a visit to the dentist are also ways to get the virus. With hepatitis B, unprotected sex can be added to this list. It also leads to infection with hepatitis A. This virus is also transmitted if you drink contaminated water or eat something prepared by a sick person who has not washed his hands.

Despite the prevalence of the disease, hepatitis is a less discussed topic than HIV or malaria, besides, people infected with the virus are stigmatized.

Fact # 3
Different types of hepatitis virus are common in different countries Viral hepatitis is spread differently around the world.

It is most common in Asia and Africa: in China, Vietnam, Cambodia and Afghanistan, 10-12 percent of people have hepatitis B. In Guinea and Liberia, this figure reaches 16 percent. In Eastern Europe (including Russia), 1-2 percent of the population is sick, and in Western Europe and North America, less than 1 percent of the population is infected with hepatitis B. Therefore, before traveling to Russia, unvaccinated Europeans and Americans are recommended to be vaccinated against hepatitis B and A).

Hepatitis C is most common in the countries of Central and East Asia and North Africa, primarily among drug addicts. But in Egypt, the story is completely different: There, in the 1960s, a campaign was carried out to combat schistosomiasis, a parasitic disease that at that time affected 40 percent of Egyptian villagers. The World Health Organization estimates that about 250,000 people have received approximately 2 million doses of the drug intravenously. Unfortunately, all this happened before the advent of disposable syringes in widespread practice. It was the insufficient precautions during the treatment of glass syringes during the mass campaign for the treatment and prevention of schistosomiasis that caused the hepatitis C epidemic in Egypt.

Fact # 4
With hepatitis B and C, liver cancer is more commonViral hepatitis is dangerous not only by itself, but also because it can lead to liver cancer.

Up to 80 percent of episodes of primary liver cancer worldwide occur in chronic carriers of viral hepatitis B or C. However, exactly how the virus causes cancer (and whether it causes it) is not entirely clear. There are several basic theories. Firstly, chronic infection of a patient with hepatitis B or C viruses leads to permanent inflammation of the liver, which leads to cirrhosis and potentially cancer. In addition, the immune system of an infected person has been attacking liver cells for years, in which the virus multiplies, which aggravates the situation. Secondly, both viruses (B and C) interfere with the molecular processes occurring in liver cells. It is not known for certain to what extent these changes contribute to the development of a cancerous tumor, but recent studies show that when the hepatitis B virus multiplies in a cell, changes occur in the genes that control its division. This, in turn, can lead to uncontrolled cell division and the growth of a cancerous tumor.

Fact #5
In some cases, vaccination can protect against hepatitisSince hepatitis is caused by different viruses, there is no single vaccination that would protect against all types of viral hepatitis.

But now you can get vaccinated against hepatitis A and B. In fact, the hepatitis B vaccine, created in 1981, became the first cancer vaccination in history: by preventing hepatitis B disease, you can significantly reduce the risk of liver cancer. In Russia, the first hepatitis B vaccination is given to newborns. Despite the fact that the vaccine has been created, scientists continue to improve it. For example, back in 2005, researchers believed that it was possible to create an oral hepatitis B vaccine in the form of genetically modified potatoes. However, these works have not yielded practical results.

There is no vaccine for hepatitis C yet. There are several reasons for this. Firstly, the hepatitis C virus is heterogeneous: viruses that have infected two different people may differ by 30-35 percent. Such diversity complicates the development of a vaccine, because in fact you need to come up with a vaccine that would be effective against a whole group of viruses. Secondly, the hepatitis C virus can successfully hide from the human immune system. This means that it is much more difficult to "incite" the immune system against the virus. There are also problems in animal model studies. In addition to humans, only chimpanzees suffer from hepatitis C, which makes it much more difficult to conduct experiments: it is much easier and cheaper to work with mice, for example, than with monkeys.

Fact # 6
Hepatitis treatment can lead to depressionViral hepatitis is often accompanied by depression.

The problem is not only that it is not always possible to cure it, but also that existing medications often lead to serious side effects, such as depression. Interferon injections, which are by far the most common method of treating hepatitis C along with the use of ribavirin, significantly increase the risk of depression: it affects from 20 to 35 percent of people receiving interferon.

How interferon contributes to the development of depression is not reliably known. There are several hypotheses. It is known that interferon alpha, used in the treatment of hepatitis C, affects brain function (in particular, the effect of interferon can be detected if an electroencephalogram is made to the patient). According to one hypothesis, interferon, which is normally produced by the body's cells in a viral disease, leads to fatigue and a desire to be alone. And when treated with interferon, these feelings become so strong that they reach the level of depression.

Fact # 7
New Hepatitis C drugs are terribly expensiveUntil recently, hepatitis C was very difficult to treat: only half of the patients who took existing drugs recovered.

It was very difficult to develop a new cure for hepatitis C, largely for the same reasons that it is so difficult to develop a vaccine: there are too many different types of the virus, and they all mutate very quickly. However, a new drug has recently entered the American market. Sofosbuvir is the first drug that acts directly on the hepatitis C virus, and not on the immune system of an infected person, blocking the activity of one of the viral proteins and thus preventing the virus from multiplying in the cell.

In clinical studies, sofosbuvir proved to be extremely effective: 90 percent of patients with chronic hepatitis C completely got rid of the infection. However, the cost of the new drug is 84 thousand dollars for a 12–week course, 1000 dollars per pill. Such a high price has caused serious discussions, even though the drug is promised to be sold much cheaper in developing countries (for example, in India, a package of sofosbuvir will cost only $ 300, that is, one percent of the price that Americans will pay). But many consider it unfair that sales in third world countries will be subsidized by sick Americans and Europeans.

Portal "Eternal youth" http://vechnayamolodost.ru12.02.2015