Hepatitis B: Symptoms, Causes, Risks, Complications, Diagnosis, Treatment, Prevention and Prognosis

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Hepatitis B

1Overview

The medical term for inflammation of the liver is hepatitis. The liver is a vital organ that functions in filtering toxins and fighting infections. When the liver is damaged or inflamed, it cannot function properly. Heavy, chronic alcohol intake, some drugs, and toxins can cause hepatitis. However, it is most often caused by a virus. In the United States, the most common types of hepatitis caused by a virus are Hepatitis A, Hepatitis B, and Hepatitis C.

Hepatitis B can become a serious liver disease that originates from an infection with the Hepatitis B virus. If the infection is short-term and occurs within the first 6 months after a person has become infected with the virus, then the condition is said to be acute hepatitis B. The infection can vary significantly in severity, ranging from a mild illness with little to no symptoms, to a serious illness requiring hospitalization. Some people, in particular adults, are able to get rid of the virus on their own without being treated. These individuals become immune to the virus and cannot become infected again.

Chronic hepatitis B refers to an infection that is lifelong. The likelihood of a person developing chronic hepatitis B depends on the age at which they become infected. Up to 90% of infants who are infected with the hepatitis B virus will develop chronic hepatitis B. Over time, this condition can cause numerous health problems, such as liver cancer, liver, damage, cirrhosis, and even death.

2Symptoms

The symptoms associated with hepatitis B vary and they are non-specific. Acute hepatitis B infection has an average incubation period of 90 days. This is the length of time it takes between infection and symptoms to show. Hepatitis B is not easily differentiated from other infectious and non-infectious illnesses that affect the liver. The clinical course may also vary from mild to severe. In almost all cases, there is a significant elevation of serum transaminase (AST, ALT). Prior to the onset of jaundice, fever, anorexia, right upper quadrant pain, headache, malaise, and aversion to tobacco may be observed. In 20% of cases, arthritis can be observed.

Chronic hepatitis B infection is characterized by inflammation of the liver accompanied by fibrosis and other changes in composition. Fibrosis occurs when the connective tissues in the liver become thicker as a means of repairing damages caused by the virus. This may then progress to death of liver tissue, known as necrosis, and destruction of the liver architecture by cirrhosis. Chronic hepatitis B infection is oftentimes asymptomatic. Occasionally, episodes of jaundice can be observed. However, there are some other symptoms that are occasionally present, such as an enlarged spleen or liver. 

3Causes

Hepatitis B is caused by the hepatitis B virus (HBV). This virus is spread predominantly by exposure to infected blood or blood products. It can also be spread by exposure to various bodily fluids, such as seminal fluids, saliva, menstrual, and vaginal fluids. Sexual transmission of hepatitis B can occur, particularly in men who have sex with men, and heterosexual partners who come into contact with sex workers or with multiple sex partners.

The virus can also be transmitted by accidentally pricking one’s self with sharp objects on which infected blood is present. This is particularly true for healthcare workers during surgical, medical, and dental procedures. Transmission can also occur through the use of contaminated needles and syringes, body piercing, tattooing, and acupuncture.

One of the major routes of HBV transmission is from the mother to the fetus. This is particularly true for people living in Southeast Asia and China.

4Risk Factors

A number of risk factors for hepatitis B have been identified. One of them is the use of injected drugs, particularly prohibited or illicit drugs. Sharing of syringes and needles, in this case, causes the virus to spread. Intranasal (snorting) of drugs is also a risk factor for HBV. Contaminated objects can also be sources of infection. Thus, sharing spoons, straws, and other cookware with infected persons is a major risk factor.

High-risk sexual activities are also major risk factors for infection. In particular, having multiple sexual partners increases the risk of acquiring HBV. Contact with sex workers such as prostitutes can also predispose a person to infection, as vaginal and seminal fluids can be vehicles for transmission.

Being born or living in a geographic location where HBV is widely spread is a risk factor. For instance, living in China is a risk factor since the overall prevalence of HBV infections there is high. Exposure to blood/blood products from patients with HBV and in regions where the virus is endemic may also be a risk factor, especially if control measures are not promptly done.

5Complications

One of the most serious complications of HBV infection is liver cirrhosis. The complications of cirrhosis are severe and include portal hypertension, uncontrolled bleeding or hemorrhage, and liver cancer. Liver cancer or hepatocellular carcinoma (HCC) can be fatal. Cirrhosis occurs when the damages in the liver caused by the virus are replaced by scar tissue. The effect is that there is less functional liver tissue. Cirrhosis occurs more frequently in older patients, those who consume or abuse alcohol, and those who are infected with a mutant strain of HBV.abuse alcohol, and those who are infected with a mutant strain of HBV.

In the early stages of infection, the liver is able to function normally and the majority of patients do not have overt symptoms. However, some experience dyspnea (difficulty of breathing), fatigue, and upper abdominal discomfort. Cirrhosis often progresses to the point that the healthy liver tissues can no longer compensate for the functions lost due to the scar tissue. When this occurs, liver failure ensues and can only be mitigated through liver transplantation.

HCC is another complication of HBV infection. Patients who have chronic hepatitis B infections are 100 times more likely to develop liver cancer compared to people who have resolved acute infections. This type of cancer, affecting the cells of the liver, emerges 25-30 years after acute infection.

6Diagnosis

The diagnosis of HBV infection requires a blood test to check for levels of HBV antigens (HBsAg), hepatitis B surface antibody (HBsAb) and hepatitis B core antibody (HBcAb). The presence of HBsAg indicates that the person is infectious. The presence of HBsAb indicates that the person is recovering and that there is immunity against HBV. HBcAb usually appears at the start of acute infections

7Treatment

The only approved drug for treating HBV infections is interferon alfa-2b. The recommended dose of the drug is 5 million units injected 5x a week for 4 months. The use of this drug was shown to be linked to a loss of serum HBsAg.

Lamivudine is another drug that can be used to treat HBV infection, and it is given at a dose of 100 mg daily.

Adefovir is another drug that was approved in 2002 to treat HBV infections. The dosage of this drug is 10 mg once a day.

If the damage to the liver is extensive, a liver transplant may be required. However, this carries the risk of rejection and the complications from surgery need to be considered as well.

8Prevention 

People who do not have HBV infections should take several measures to prevent infections. These measures include refraining from having multiple sexual partners, having sex with prostitutes, and having close physical contact with infected persons. Some safety measures during sexual activities can also be done, such as using a condom each time. Refraining from sharing razors and toothbrushes with persons who are infected is another way to prevent HBV infection. Refraining from using illicit drugs is another preventive measure against HBV infection. Syringes and needles should never be shared.

Another way to prevent HBV infection is through vaccination. Vaccines against HBV have been available since 1982. Vaccination is the most effective way to prevent HBV infection. The vaccine is effective up to 95% against hepatitis B. There are 3-4 shots given at different times and when these shots are complete, there is close to 100% protection against HBV infection. It provides protection against infection for at least 20 years. There is also a vaccine that protects against both hepatitis A and hepatitis B.

9Prognosis

Acute HBV infections usually stay in the body from 1-3 months. It resolves on its own without treatment. However, 1 in 20 people will acquire the chronic infection. The prognosis for those with this type of HBV infection depends on the management of the disease. There is a worse prognosis if the person develops cirrhosis, which can lead to liver failure and eventually death. The prognosis for people with HCC is also worse, as it can also lead to death. A rare outcome of hepatitis B is fulminant hepatitis B, which occurs when the body attacks the liver. It is a severe condition, and the prognosis for this complication is poor. The outcomes include confusion, ascites, and jaundice. The prognosis for chronic HBV infection is generally worse than that of acute HBV infection. Thus, HBV needs to be prevented through widespread vaccination.