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Hepatitis. Hepatitis is an inflammation of the liver. Hepatitis is caused by several types of viruses as well as drug and chemical toxicity. Hepatitis A. Caused by Hepatitis A virus Single stranded RNA and lacks an envelope.
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Hepatitis is an inflammation of the liver. • Hepatitis is caused by several types of viruses as well as drug and chemical toxicity.
Hepatitis A • Caused by Hepatitis A virus • Single stranded RNA and lacks an envelope. • Enters the body through the oral route and multiplies in the epithelial lining of the intestinal tract. Viremia occurs and spreads the virus to the liver, spleen, and kidneys. • At least 50% of of infections with HAV are subclinical. • In clinical cases symptoms are loss of appetite, malaise, nausea, diarrhea, abdominal discomfort, fever, and chills.
Hepatitis A • There is no chronic form of hepatitis A. • Incubation time ranges from 2-6 weeks. • Acute disease is diagnosed by the detection of IgM anti-HAV. • No specific treatment for the disease exists. • Immune globulin is given to high people at risk for exposure to HAV
Hepatitis B • Caused by the Hepatitis B virus. • HBV is larger than HAV • Its genome is double stranded DNA. • Unlike HAV, HBV is enveloped. • Has three distinct particles. • The Dane particle which is the completed virion. It is infectious and is capable of replication. • The spherical particle which is about half the size of the Dane particle. • The filamentous particle which has the same diameter as the spherical particle but is ten times as long
Hepatitis B • The filamentous particles and the spherical particles are unassembled parts of the Dane particles without nucleic acids. • These unassembled particles contain hepatitis B surface antigen which can be detected by antibodies to them. • Antibody tests make convenient screening of blood for HBV.
Hepatitis B • The incubation period of Hepatitis B is about 4-26 weeks. • Symptom are similar to HAV with the exception of headaches. • HBV is more likely to progress to severe liver damage.
Hepatitis C • Caused by the hepatitis C virus. • HCV has a single strand of RNA and is enveloped. • HCV is capable of rapid genetic variation to evade the immune system. • A PCR test for viral RNA can be used to determine if there is an HCV infection.
Hepatitis C • Symptoms of HCV are similar to HBV. • HCV is more likely to become a chronic condition. • Few people have recognizable symptoms until 20 years have elapsed • The treatment of choice is a combination of peginterferon alfa-2A and ribavirin.