Infectious hepatitides are a broad group of diseases. The most important are so-called hepatitides caused by hepatotropic (liver-invading) viruses A, B, C, D and E and this text is dedicated right to those viruses.
Note: However, we should know that there are more microorganisms that can cause infectious hepatitis. It is for example the EBV virus, which causes liver damage in infectious mononucleosis.
The various types of infectious hepatitis are caused by completely different viruses and this causes their different attributes. However, the basic scheme of the disease's course is somehow similar: infection - incubation period - acute infection (symptomatic or almost asymptomatic) - recovery / transition into chronic disease / extremely rapid progression with acute liver failure.
From the epidemiological point of view, hepatitis A is a significant infectious disease, which is capable of causing local epidemics. However, its course is usually benign.
The disease belongs among so-called "diseases of dirty hands". The source is usually stool of an infected person and everything it has contaminated. It is transmitted due to poor hygienic standard, the majority of people infect from inadequately cooked food contaminated by the virus. The infection can also develop from contaminated water.
Best prevention is keeping adequate hygienic standards (especially washing hands) and eating only food from safe known sources when on vacation in less developed countries. Generally appropriate is in such case drinking only bottled water, not to buy food on the street and not to drink beverages with ice (because we do not know the origin of the ice). Of course, an important element of prevention is the vaccination.
The disease occurs in about 30 days after the infection (± 2 weeks) with nonspecific flu-like symptoms, abdominal pain, nausea, vomiting and liver enlargement. Hepatitis A is very often accompanied by jaundice (yellow color of mucosa, skin and eyes), pale stool and dark urine. The immune system usually quickly defeats the viruses, leading to a quick recovery. Only extremely rarely, the infection can cause rapid deterioration and sudden liver failure.
There exists an effective vaccine.
The main way of treatment is bed rest and diet with avoiding alcohol and fats. Hepatoprotectives may be used, but their effect is rather controversial.
This disease is caused by a completely different virus than the hepatitis A, and the attributes are therefore distinct as well.
The hepatitis B is transmitted by blood and other body fluids, for example by unprotected sex, intravenous drugs, blood transfusions, dialysis tattoos and the transfer is even possible from a sick mother to her fetus.
The best prevention is protected sex and avoidance of intravenous drug addiction.
The symptoms of disease occur after a longer period of time, in average in 2-3 months after the infection. The acute manifestations are similar to hepatitis A. However, the following course of the disease has more possibilities. The majority of infected fully recover and the infection disappears. About 15% of people do not cure the disease and it develops into a chronic form. Chronic hepatitis means that the person remains infectious and can suffer from many unspecific digestive problems. The liver tests are usually chronically elevated. Some chronic forms may progress into liver cirrhosis with all its complications, including the liver cancer. Only exceptionally, the acute infection of hepatitis B can have rapid course that causes liver failure.
Vaccination is possible.
In the active stage, bed rest and diet are necessary. If laboratory testing detects the progression into chronic stage, the patient is treated by special drugs (interferons). People in the chronic stage should fully cooperate with doctors and avoid any substances that could further deteriorate the liver condition such as alcohol.
The disease is most commonly transmitted by infected blood or other body fluids. It is widespread among intravenous drug users. The disease may be incidentally found in its chronic form years after the infection, when the mechanism of transmission can be no longer detected.
Best methods of prevention are protected sex, avoidance or intravenous drugs, or at least avoidance of sharing syringes when using those drugs.
The disease has an incubation period of about 2 months after the infection and it behaves very insidiously. The acute form has very mild symptoms, or it has no symptoms at all. Jaundice is usually not present! The immune system is in the majority of cases incapable of defeating the virus and the infection progresses into chronic form with a very high chance of liver cirrhosis with its complications.
There is no effective vaccine!
Acute form is very difficult to diagnose, but when it is confirmed, the therapy consists of dietary measures (prohibition of alcohol) and reduced intake of fats. Chronic forms are treated by interferon and special antiviral drug ribavirin. Full cooperation with the doctors is very important, chronic form is very dangerous and threatens the patient with development of liver cirrhosis.
It is caused by an imperfect virus, which is not able to attack the liver on its own and it needs contemporary presence of hepatitis B virus.
Prevention and transmission
It is same as in hepatitis B.
The symptoms and course of the disease depend on how the infection has occurred. If a person contracted both viruses (B and D) together, the infection is less dangerous and usually uncomplicated. However, when a patient gets infected by hepatitis D, while already suffering from hepatitis B, the resulting infection has a higher chance of progress to chronic disease and it may also cause a rapid progression with acute liver failure.
It is same as in hepatitis B.
This infection is cause by hepatitis E virus. The source is infected human stool and any contaminated food or water. Similarly to hepatitis A, hepatitis E is a "disease of dirty hands", which spreads in populations with improper hygiene. The symptoms and course of the disease is also very similar to hepatitis A. Most patients suffer from acute liver inflammation with jaundice and recover. In only small percentage of cases, the disease may progress into chronic form (e.g. in immunocompromised people).
The therapy consists of isolation, bed rest, dietary measures and administration of hepatoprotective agents.