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.• 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.