VIRAL HEPATITIS


INTRODUCTION
Hepatitis refers to an inflammatory condition of the liver. It’s commonly caused by a viral infection, but there are other possible causes of hepatitis. These include autoimmune hepatitis and hepatitis that occurs as a secondary result of medications, drugs, toxins, and alcoholAutoimmune hepatitis is a disease that occurs when your body makes antibodies against your liver tissue.
Viral hepatitis is caused mainly by infection with one of the five hepatitis viruses, which use the liver as their primary site of replication. Each of these, known as hepatitis A through E viruses (HAV to HEV), belong to different virus families, have unique morphology, genomic organization and replication strategy. These viruses cause similar clinical manifestations during the acute phase of infection but vary in their ability to cause chronic infection. While HAV and HEV cause only acute disease with no chronic sequelae, HBV, HCV and HDV cause varying degrees of chronicity and liver injury, which can progress to cirrhosis and liver cancers. Though specific serological tests are available for the known hepatitis viruses, nearly 20% of all hepatitis cases show no markers. Antiviral therapy is also recommended for some hepatitis viruses and a preventive vaccine is available only for hepatitis B. More research and public awareness programmes are needed to control the disease.
                   TYPES OF HEPATITIS
·        Infectious
·        Non infectious
INFECTIOUS HEPATITIS
Viral infections of the liver that are classified as hepatitis include hepatitis A, B, C, D, and E. A different virus is responsible for each type of virally transmitted hepatitis. Hepatitis A is always an acute, short-term disease, while hepatitis B, C, and D are most likely to become ongoing and chronic. Hepatitis E is usually acute but can be particularly dangerous in pregnant women.

Hepatitis A

Hepatitis A is caused by an infection with the hepatitis A virus (HAV). This type of hepatitis is most commonly transmitted by consuming food or water contaminated by feces from a person infected with hepatitisA.

Hepatitis B

Hepatitis B is transmitted through contact with infectious body fluids, such as blood, vaginal secretions, or semen, containing the hepatitis B virus (HBV). Injection drug use, having sex with an infected partner, or sharing razors with an infected person increase your risk of getting hepatitis B.

Hepatitis C

Hepatitis C comes from the hepatitis C virus (HCV). Hepatitis C is transmitted through direct contact with infected body fluids, typically through injection drug use and sexual contact. HCV is among the most common bloodborne viral infections.

Hepatitis D

Also called delta hepatitis, hepatitis D is a serious liver disease caused by the hepatitis D virus (HDV). HDV is contracted through direct contact with infected blood. Hepatitis D is a rare form of hepatitis that only occurs in conjunction with hepatitis B infection. The hepatitis D virus can’t multiply without the presence of hepatitis B. It’s very uncommon in the United States.

Hepatitis E

Hepatitis E is a waterborne disease caused by the hepatitis E virus (HEV). Hepatitis E is mainly found in areas with poor sanitation and typically results from ingesting fecal matter that contaminates the water supply. This disease is uncommon in the United States. However, cases of hepatitis E have been reported in the Middle East, Asia, Central America, and Africa, according to the CDC

 Non-infectious hepatitis

CAUSES

Alcohol and other toxins

Excessive alcohol consumption can cause liver damage and inflammation. This is sometimes referred to as alcoholic hepatitis. The alcohol directly injures the cells of your liver. Over time, it can cause permanent damage and lead to liver failure and cirrhosis, a thickening and scarring of the liver.
Other toxic causes of hepatitis include overuse or overdose of medications and exposure to poisons.

Autoimmune system response

In some cases, the immune system mistakes the liver as a harmful object and begins to attack it. It causes ongoing inflammation that can range from mild to severe, often hindering liver function. It’s three times more common in women than in men.

SIGNS AND SYMPTOMS
If infectious forms of hepatitis that are chronic, like hepatitis B and C, there may not be symptoms in the beginning. Symptoms may not occur until the damage affects liver function.
Signs and symptoms of acute hepatitis appear quickly. They include:
·         fatigue
·         dark urine
·         pale stool
·         abdominal pain
·         loss of appetite
·         unexplained weight loss
·         yellow skin and eyes, which may be signs of jaundice
Chronic hepatitis develops slowly, so these signs and symptoms may be too subtle to notice.
MANAGEMENT (INVESTIGATIONS AND TREATMENT)
DIAGNOSIS

History and physical examination

To diagnose hepatitis, history to determine any risk factors for infectious or noninfectious hepatitis.
During a physical examination, press down gently on the abdomen to see if there’s pain or tenderness or liver is enlarged. If skin or eyes are yellow, it is noted during the examination.

Liver function tests

Liver function tests use blood samples to determine how efficiently the liver works. Abnormal results of these tests may be the first indication that there is a problem, especially if there are no signs on a physical examination of liver disease. High liver enzyme levels may indicate that the liver is stressed, damaged, or not functioning properly.

Other blood tests

If the liver function tests are abnormal, bloodtests may be done to detect the source of the problem. These tests can check for the viruses that cause hepatitis. They can also be used to check for antibodies that are common in conditions like autoimmune hepatitis.

Ultrasound

An abdominal ultrasound uses ultrasound waves to create an image of the organs within your abdomen. This test allows to take a close look  at the liver and nearby organs. It can reveal:
·         fluid in the abdomen
·         liver damage or enlargement
·         liver tumors
·         abnormalities of your gallbladder
Sometimes the pancreas shows up on ultrasound images as well. This can be a useful test in determining the cause of the abnormal liver function.

Liver biopsy

liver biopsy is an invasive procedure that involves taking a sample of tissue from the liver. It can be done through the skin with a needle and doesn’t require surgery. Typically, an ultrasound is used to guide the physician when taking the biopsy sample.
This test allows determining how infection or inflammation has affected the liver. It can also be used to sample any areas in the liver that appears abnormal.
 TREATMENT
Treatment options are determined by which type of hepatitis you have and whether the infection is acute or chronic.

Hepatitis A

Hepatitis A usually doesn’t require treatment because it’s a short-term illness. Bed rest may be recommended if symptoms cause a great deal of discomfort. The hepatitis A vaccine is available to prevent this infection. Most children begin vaccination between ages 12 and 18 months. It’s a series of two vaccines. Vaccination for hepatitis A is also available for adults and can be combined with the hepatitis B vaccine.

Hepatitis B

Acute hepatitis B doesn’t require specific treatment. Chronic hepatitis B is treated with antiviral medications. This form of treatment can be costly because it must be continued for several months or years. Treatment for chronic hepatitis B also requires regular medical evaluations and monitoring to determine if the virus is responding to treatment. Hepatitis B can be prevented with vaccination. The CDC recommends hepatitis B vaccinations for all newborns. The series of three vaccines is typically completed over the first six months of childhood. The vaccine is also recommended for all healthcare and medical personnel.

Hepatitis C

Antiviral medications are used to treat both acute and chronic forms of hepatitis C. People who develop chronic hepatitis C are typically treated with a combination of antiviral drug therapies. They may also need further testing to determine the best form of treatment.
People who develop cirrhosis (scarring of the liver) or liver disease as a result of chronic hepatitis C may be candidates for a liver transplant.
Currently, there is no vaccination for hepatitis C.

Hepatitis D

No antiviral medications exist for the treatment of hepatitis D at this time. According to a study, a drug called alpha interferon can be used to treat hepatitis D. Hepatitis D can be prevented by getting the vaccination for hepatitis B, as infection with hepatitis B is necessary for hepatitis D to develop.

Hepatitis E

Currently, no specific medical therapies are available to treat hepatitis E. Because the infection is often acute, it typically resolves on its own. People with this type of infection are often advised to get adequate rest, drink plenty of fluids, get enough nutrients, and avoid alcohol. However, pregnant women who develop this infection require close monitoring and care.

Autoimmune hepatitis

Corticosteroids, like prednisone or budesonide, are extremely important in the early treatment of autoimmune hepatitis. Azothioprine (Imuran), a drug that suppresses the immune system, is often included in treatment. It can be used with or without steroids. Other immune suppressing drugs like mycophenolate (CellCept), tacrolimus (Prograf) and cyclosporine (Neoral) can also be used as alternatives to azathioprine for treatment.

PREVENTION

1.     Hygiene

Practicing good hygiene is one key way to avoid contracting hepatitis A and E. If you’re traveling to a developing country, you should avoid:
·         local water
·         ice
·         raw or undercooked shellfish and oysters
·         raw fruit and vegetables
Hepatitis B, C, and D contracted through contaminated blood can be prevented by:
·         not sharing drug needles
·         not sharing razors
·         not using someone else’s toothbrush
·         not touching spilled blood
Hepatitis B and C can also be contracted through sexual intercourse and intimate sexual contact. Practicing safe sex by using condoms can help decrease the risk of infection.

2.     Vaccines

The use of vaccines is an important key to preventing hepatitis. Vaccinations are available to prevent the development of hepatitis A and B. Experts are currently developing vaccines against hepatitis C. A vaccination for hepatitis E exists in China.
PATHOPHYSIOLOGY: Each of the hepatitis viruses cause similar liver damage. The inflammatory process is activated throughout the whole liver, and hepatocytes are destroyed by cytotoxic cytokines and natural killer cells, both parts of the inflammatory process.  Cellular necrosis takes place. If inflammation affects the periportal areas, cholestasis, or the interruption of the flow of bile takes place. The liver is usually able to repair itself and regain complete function if no other complications occur.
The antigen-antibody complexes that are formed from the interaction of the immune system with the infection circulate thoughout the body, which activates the complement system. The person feels malaise, rash, arthritis, fever and angioedema from this activation. Abnormal protiens are also produced in the blood, termed cryogloblinemia. The person may also develop vasculitis and glomerulonephritis.
There are three phases during a typical course of acute hepatitis.
1. Prodromal phase. This phase begins about 2 weeks after exposure to hepatitis. The infection is easily transmitted during this phase. The signs and symptoms are malaise, fatigue, anorexia, nausea, vomiting, cough, hyperalgia, low-grade fever. This stage ends when jaundice appears.
2. Icteric phase. This phase is characterized by dark urine, jaundice and clay-colored stools. The liver becomes enlarged, tender and smooth and the person feels pain if the liver is percussed. This is known as the actual phase of illness. It begins 1-2 weeks after the prodromal phase and continues for 2-6 weeks.
3. Recovery phase. The recovery begins when the jaundice starts to clear. The liver stays enlarged and tender but the other symptoms start to diminsh. It usually begins 6-8 weeks after exposure. The liver regains normal function 2-12 weeks after the jaundice begins.
Chronic hepatitis is defined as "the persistance of clinical manifestations and liver inflammation after acute hepatitis B, hepatitis C, and hepatitis D. Liver function tests remain abnormal for longer than 6 months, and hepatitis B surface antigen (HbsAg) persists" .
Complications of hepatitis
Chronic hepatitis B or C can often lead to more serious health problems. Because the virus affects the liver, people with chronic hepatitis B or C are at risk for:
·         chronic liver disease
·         cirrhosis
·         liver cancer
When the liver stops functioning normally, liver failure can occur. Complications of liver failure include:
·         bleeding disorders
·         a buildup of fluid in the abdomen, known as ascites
·         increased blood pressure in portal veins that enter the liver, known as portal hypertension
·         kidney failure
·         hepatic encephalopathy, which can involve fatigue, memory loss, and diminished mental abilities due to the buildup of toxins, like ammonia, that affect brain function
·         hepatocellular carcinoma, which is a form of liver cancer
·         death
People with chronic hepatitis B and C are encouraged to avoid alcohol because it can accelerate liver disease and failure.

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