Hepatitis Viruses

Hepatitis viruses are a group of viruses which principally affect the liver cells and cause inflammation.

Examples of hepatitis viruses transmitted by contact are Hepatitis B virus and Hepatitis C virus.

Hepatitis B Virus (HBV)

HBV is a member of family hepadna virus

HBV is a DNA enveloped virus

Has icosahedral nucleocapsid core containing partially double stranded circular DNA genome

The envelope contains a protein called surface “antigen” (Hepatitis B surface antigen)

HCV is a single stranded RNA virus, classified as family Flaviviridae, genus Hepacivirus

It is an enveloped virus, surrounded by a protective shell of protein, and further encased in a lipid (fatty) envelope of cellular material

The genome of HCV is highly mutable

By constant mutation, HCV may be able to escape host immunologic detection and elimination

Diseases Caused by Hepatitis B Virus

The virus causes serum hepatitis characterized by persistent infection leading to chronic hepatitis, liver cirrhosis, hepatocellular carcinoma, and liver necrosis.

Hepatitis B is not directly cytopathic, instead damage to the liver is mediated by the immune response.

This virus can cause an acute infection, which appears 6 weeks to 6 months after exposure, as well as a chronic infection, which lasts for more than 6 months

It is common for acute infections to become chronic, the probability of someone becoming chronically infected with HBV is inversely related to the age of infection.

Infections at an earlier age increase the chances of becoming a chronic carrier of the virus.

Thus, babies born to infected mothers are at very high risk of to becoming carriers and developing liver pathology

Hepatocellular carcinoma (HCC), also called malignant hepatoma, is the most common type of liver cancer. Most cases of HCC are as a result of either a viral hepatitis infection (hepatitis B or C), metabolic toxins such as alcohol or aflatoxin, conditions like hemochromatosis and alpha 1-antitrypsin deficiency.

In the United States, hepatocellular carcinoma can be found during routine screening examinations or found incidentally on exams performed for other unrelated reasons. While some patients may not have symptoms, others may experience:

Weight loss

Blood in the stool

Jaundice

Fatigue

Fluid in abdomen

The clinical course of acute hepatic necrosis resembles an acute, toxic injury to the liver with sudden and precipitous onset, marked elevations in serum aminotransferase levels, and early signs of hepatic (or other organ) dysfunction or failure despite minimal or no jaundice

Cytopathic effect or cytopathogenic effect (abbreviated CPE) refers to structural changes in host cells that are caused by viral invasion.

Blood for serology: for example ELISA, Counter-immune-electrophoresis (CIE), and PCR

Drug of Choice

Alpha interferon and Lamivudine,

Hepatitis C

Diseases caused by Hepatitis C virus are

Hepatitis

Hepatocellular carcinoma

HCV infection sometimes results in an acute illness, but most often becomes a chronic condition that can lead to cirrhosis of the liver and liver cancer.

Abdominal ultrasound. This test helps the doctor see the tumor

CT scan. This test identifies the tumor(s) and pinpoints their size and location in the liver, as well as their relation to the vascular / biliary structures. It also helps the doctor to determine the overall health of the liver.

This test identifies the tumor(s) and pinpoints their size and location in the liver, as well as their relation to the vascular / biliary structures. It also helps the doctor to determine the overall health of the liver. A doctor will determine whether to do a CT scan, an MRI or both.

Liver biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope.

Blood work. Blood tests may include a complete blood count, hematocrit, platelet count, liver function tests, and alpha fetoprotein, which may be elevated in patients with liver cancer.

Blood for serology, for example ELISA, Counter-immuno-electrophoresis (CIE), and PCR

Drug of Choice

Alpha interferon plus Ribavirin

Hepatitis B is classified as family hepadnaviridae

Hepatitis B is the causative agent of serum hepatitis

The envelop of hepatitis B consists of hepatitis B surface antigen

Hepatitis C is classified as family flaviviridae

Hepatitis C is the causative agent of post transfusion hepatitis

What are the characteristics of Hepatitis B and C viruses?

What are the diseases caused by Hepatitis B and C viruses?