How many hepatitis viruses are there and how are they different? & bull; hello healthy

Definition

What is viral hepatitis?

Viral hepatitis is an infection that causes inflammation in the liver. This condition is caused by infection with the hepatitis virus that replicates in liver cells. So far there are five types of viruses that cause hepatitis.

The five of them have different characteristics and affect the health of the body, namely:

hepatitis A,
hepatitis B,
hepatitis C,
hepatitis D, and
hepatitis E.

The five viruses generally show the same symptoms in the infection stage that lasts less than 6 months (acute hepatitis).

However, some hepatitis virus infections such as HBV, HCV, and HDV can progress to a chronic stage, giving complications or more severe health effects.

Meanwhile, the causes of the emergence of this virus are quite diverse, ranging from alcohol abuse to the use of certain drugs.

Hepatitis A

Hepatitis A virus (HAV) is a group of RNA viruses in the Picornaviridae group that can survive in environments with low pH and temperature.

This virus can move quickly from one person to another throughfecal-oral, namely the digestive tract. For example, consumption of food and drink contaminated with feces that contain viruses.

In addition, poor hygiene levels, inadequate sanitation facilities, and unhygienic food processing also affect the spread of the hepatitis A virus.

Not only in feces, the hepatitis A virus is also present in the blood and body fluids so that hepatitis A is transmitted through sexual contact. The process of blood transfusion is also possible, although it is rare.

How does HAV infection process?

When the body digests contaminated food, the virus will enter the blood vessels through the epithelial tissue. Blood carries the virus to the organ that is the target of viral infection, namely the liver. The virus will later replicate in hepatocyte cells.

Before replicating, the virus will go through an incubation period of 2-7 weeks. That is why no health problems have emerged after you have been exposed to HAV.

If the virus has been actively infecting, the HAV antigen and IgM antibody will appear in the blood. Both play an important role in detecting and diagnosing hepatitis A.

A number of health problems arise as a result of the immune system's reaction to fighting viral infections in liver cells. The immune system continues to secrete T-cells to stop infection as well as fight HAV.

As a result, the body lacks supply of T cells, resulting in impaired liver function. On the other hand, the symptoms of hepatitis A are mild, they don't even show signs at all.

Even so, many infected people develop jaundice as a sign of the end of the period of HAV infection.

Infection recovery phase

Hepatitis A virus infection can stop on its own within a few weeks without any special treatment.

When the infection stops, the virus does not completely disappear in the body, but is inactive (dormant).

People who are infected with this virus will then build up antibodies which will protect them from future HAV attacks.

Hepatitis B

Hepatitis B virus (HBV) is a type of viral DNA composed of multiple cells. That is, the part of the cell nucleus which contains the HBV antigen (HBcAg) and the cell sheath consists of the HBsAg surface antigen.

HBV is a group of viruses Hepadnaviridae which can withstand extreme temperature and humidity conditions. Outside the human body, this virus can also survive at room temperature for 6 months.

The virus in HBV patients is mostly found in the blood. The presence of both HBV antigens in the blood is a measure used to detect hepatitis B disease. This also plays an important role in controlling disease progression.

Hepatitis B is also divided into two types based on the length of time, namely:

acute hepatitis B (short term), and
chronic hepatitis B (long term).

Acute HBV infection

People who are infected with the hepatitis B virus usually find HBV in their fluids or blood in their bodies. HBV transmission occurs most commonly through blood transfusions, use of needles and childbirth.

The incubation period for hepatitis B will last for 2 - 4 weeks before actively replicating in hepatocyte cells. At the time of infection, the core part of the virus will replace the nucleus of hepatocytes while releasing part of the antigen into the serum or blood.

Hepatocyte cell damage resulting in inflammation of the liver is caused by the immune system's (autoimmune) response to viral infection.

Acute hepatitis B virus infection lasts 2 - 3 weeks. If the antibodies are strong enough to protect the body from virus attack, the body will undergo a viral clearance phase after 3 - 6 months.

Like other types of hepatitis, hepatitis B usually has no symptoms. Inflammation will then subside and the function of the liver cells will gradually return to normal.

The presence of HBV can no longer be detected by the body. However, the HBsAg surface antigen will appear and indicate the presence of antibodies that are ready to protect the body from hepatitis B virus infection again.

Chronic HBV infection

If the body is infected with the hepatitis B virus for more than 6 months, it means that the viral infection has reached a chronic stage. Generally, chronic infection increases the risk of developing more severe hepatitis B symptoms.

According to articles fromJournal of Tropical Pediatrics, chronic HBV infection occurs when the virus develops massively. It also occurs when the hepatocytes lose their viral DNA and the viral infection is no longer overwhelmed by resistance from the immune system.

As a result, hepatocyte cells are destroyed over time and turn into scar tissue. This condition indicates fibrosis or hardening of the liver. Fibrosis is the initial stage of the formation of cirrhosis or liver cancer.

Hepatitis C

Hepatitis C virus (HCV) is the cause of hepatitis C. This virus is a type of RNA virus Flaviviridae. HCV consists of a core part in the form of RNA which is protected by protein and lipid cells, as well as glycoproteins that attach to the protective cell.

HCV has many genetic variations. So far, this virus is classified into 7 types of genes that have at least 67 subtypes. HCV is a type of virus that is difficult for the human immune system to fight.

This virus can multiply massively, so that autoimmune reactions have difficulty keeping up with the number of viruses.

In addition, HCV has a high mutation ability. This virus can also change shape into different genetic subtypes. This makes it difficult for the immune system to recognize the virus when it tries to fight it.

Nearly 80% of people diagnosed with HCV have chronic hepatitis C.

Chronic HCV infection

The hepatitis C virus is mainly transmitted through the use of needles for unsterile blood vessels.

Unlike HBV infection which still has the possibility to go away on its own, HCV infection tends to progress to a chronic phase.

Liver function disorders that arise in hepatitis C are due to the mediation of immune cells that react to the development of the virus in the liver. As a result, the symptoms of chronic hepatitis C are more severe.

The risk of chronic infection is the emergence of various complications of hepatitis C such as cirrhosis, liver cancer, and permanent liver failure.

Hepatitis D

Hepatitis D virus (HDV) has different characteristics from other types of hepatitis. Apart from its smallest size, HDV also does not replicate without HBV. That is why hepatitis D patients must have been infected with HBV first or simultaneously.

So far, at least 8 types of HDV genes have been found. HDV type 1 is the type of virus that most often causes hepatitis C in the world, including in Asia.

Transmission of HDV is generally through needle puncture, whether medical or drug, which is not sterile or shared.

The incubation period for hepatitis D virus will also follow the active period of infection from the virus that causes hepatitis B. Hepatitis D virus infection has the most dangerous impact of other hepatitis.

There are two types of infections that can be caused by HDV, namely co-infection and superinfection.

Co-infection

Co-infection occurs when HDV infection coincides with HBV infection that occurs in hepatocytes. This infection occurs when the HBV infection period is still short (less than 6 months) or the acute infection phase.

Co-infection can cause disease characteristics that range from causing moderate symptoms to serious liver disease, such as fulminant hepatitis.

Superinfection

If you have been infected with chronic hepatitis B and have the hepatitis D virus, it means that your body is superinfected. The health problems caused by superinfection also vary.

Generally, superinfection can cause severe hepatitis D symptoms in a short time. In fact, this infection can worsen symptoms of chronic hepatitis B and increase the risk of developing symptoms.

In addition, superinfection will accelerate the development of hepatitis D, causing a number of complications such as cirrhosis of the liver and liver cancer.

Hepatitis E

Hepatitis E virus (HEV) is a type of RNA virus that is part of the Hepeviridae group. This virus has a structure and genome similar to that of the norovirus. Previously, this virus was also known as ET-NANB (hepatitis non-A and hepatitis non-B).

Transmission is the same as the way hepatitis A is spread, namely through contaminated food and drink. However, the spread of HEV can also occur vertically, namely from mother to baby or during the blood transfusion process.

Hepatitis E outbreaks mostly occur in developing countries. This may be influenced by poor sanitation facilities and a lack of clean water sources.

Before actively infecting hepatocyte cells, HEV undergoes an incubation period of 2 - 10 weeks. Viral infections that do occur are asymptomatic, but there is still a risk of the infection progressing from acute hepatitis to liver failure.