Thursday, 30 August 2012

Hepatitis-B (part-2)


How is the hepatitis B virus spread (transmitted)?


Hepatitis B is spread mainly by exposure to
1.   Infected blood or body secretions.
2.   In infected individuals, the virus can be found in the blood, semenvaginal discharge, breast milk and saliva.
3.   Hepatitis B is not spread through food, water, or by casual contact.
4.   Sexual contact is the most common means of transmission.
5.   Using contaminated needles for injecting illicit drugs, tattooing, body piercing, or acupuncture. Additionally,
6.   Sharing toothbrushes and razors contaminated with infected fluids or blood.
7.   infected mothers to their babies at birth (so-called 'vertical' transmission). The rate of transmission of hepatitis B from mother to newborn is very high, and almost all infected infants will develop chronic hepatitis B. Fortunately, transmission can be significantly reduced through immune prophylaxis.
Rarely, hepatitis B can be transmitted through transfused blood products, donated livers and other organs. However, blood and organ donors are routinely screened for hepatitis which typically prevents this type of transmission.

What are the symptoms of acute hepatitis B?


Period of illness that occurs during the first one to four months after acquiring the virus. Only 30% to 50% of adults develop significant symptoms during acute infection. Early symptoms may be non-specific, including fever, a flu-like illness, and joint pains. Symptoms of acute hepatitis may include:
·         fatigue,
·         loss of appetite,
·         nausea,
·         jaundice (yellowing of the skin and eyes), and
·         pain in the upper right abdomen (due to the inflamed liver).
It is found rarely that Acute hepatitis damages the liver so badly it can no longer function. This life-threatening condition is called "fulminant hepatitis." Patients with fulminant hepatitis are at risk of developing bleeding problems and coma resulting from the failure of the liver. Patients with fulminant hepatitis should be evaluated for liver transplantation.
What determines the outcome of acute hepatitis B?

The immune response of body is the major determinant of the outcome in acute hepatitis B. Individuals who develop a strong immune response to the infection are more likely to clear the virus and recover.
However, these patients also are more likely to develop more severe liver injury and symptoms due to the strong immune response that is trying to eliminate the virus. but a weaker immune response results in less liver injury and fewer symptoms but a higher risk of developing chronic hepatitis B. People who recover and eliminate the virus will develop life-long immunity, that is, protection from subsequent infection from hepatitis B.

What are the symptoms of chronic hepatitis B?



The liver functions include a role in the immune system, production of clotting factors, producing bile for digestion, and breaking down toxic substances, etc.
The signs and symptoms of chronic hepatitis B vary widely depending on the severity of the liver damage. They range from few and relatively mild signs and symptoms to signs and symptoms of severe liver disease such as cirrhosis or liver failure.
Mostly chronic hepatitis B remain symptom free for many years or decades. During this time, the patient's blood tests usually are normal or only mildly abnormal. Some patients may deteriorate and develop inflammation or symptoms, putting them at risk for developing cirrhosis.
Cirrhosis of the liver due to hepatitis B

Inflammation from chronic hepatitis B can progress to cirrhosis (severe scarring) of the liver. Significant amounts of scarring and cirrhosis lead to liver dysfunction.
Symptoms may include:
·         weakness
·         fatigue,
·         loss of appetite,
·         weight loss
·         breast enlargement in men,
·         a rash on the palms,
·         difficulty with blood clotting, and
·         spider-like blood vessels on the skin.
·         Decline d absorption of vitamins A and D can cause impaired vision at night and thinning of bones (osteoporosis).
·         The cirrhosis of liver also are at risk of infections because the liver plays an important role in the immune system.
Advanced cirrhosis of the liver due to hepatitis B

In patients with advanced cirrhosis, the liver begins to fail. This is life-threatening condition.
Several complications occur in advanced cirrhosis:
·         Confusion and even coma (encephalopathy) results from the inability of the liver to detoxify certain toxic substances.
·         Aabdominal cavity of blood vessels is develop in the live r due to increased pressure  in blood vessels (portal hypertension) causes fluid to build up in the (ascites) and may result in engorged veins in the swallowing tube (esophageal varices) that tear easily and may cause massive bleeding.
·         Portal hypertension can also cause kidney failure or an enlarged spleen resulting in a decrease of blood cells and the development of anemia, increased risk of infection and bleeding.
·         Advanced stage of cirrhosis, liver failure also results in decreased production of clotting factors. This causes abnormalities in blood clotting and sometimes spontaneous bleeding.
·         Patients with advanced cirrhosis often develop jaundice because the damaged liver is unable to eliminate a yellow compound, called bilirubin.

Hepatitis B virus and primary liver cancer
(hepatocellular carcinoma)


Developing liver cancer with chronic hepatitis B. Patients may have no symptoms, or they may experience abdominal pain and swelling, an enlarged liver, weight loss, and fever. The most useful diagnostic screening tests for liver cancer are a blood test for a protein produced by the cancer called alpha-fetoprotein and an ultrasound imaging study of the liver. These two tests are used to screen patients with chronic hepatitis B, especially if they have cirrhosis or a family history of liver cancer.
Other organ involvement in Hepatitis B (extra-hepatic)

Rarely, chronic hepatitis B infection can lead to disorders that affect organs other than the liver. These conditions are caused when the normal immune response to hepatitis B mistakenly attacks uninfected organs.



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