hepatitis virus : bds 2nd year

Hepatitis A And

Hepatitis B

What is viral hepatitis…?

Viral hepatitis is a systemic disease with primary inflammation to the liver.

TYPES : A B C D E and G

A“Infectious”

“Serum”

Viral hepatitis

E

Nor A nor B(NANB)

B C

Viral Hepatitis - Historical Perspectives

Other D OR G

Hepatitis Terms• Acute Hepatitis: Short-term hepatitis.

– Body’s immune system clears the virus from the body within 6 months

• Chronic Hepatitis: Long-term hepatitis.– Infection lasts longer than 6 months because the body’s

immune system cannot clear the virus from the body

HEPATITIS AMorphologic Characteristics • 27nm• Non enveloped• Single stranded RNA• icosahedral• Naked RNA virus• Related to enteroviruses,• formerly known as enterovirus 72, now put in its

own family: heptovirus.• Difficult to grow in cell culture.

LABORATORY DIAGNOSIS

1. DEMONSTRATION OF VIRUSIEMELISAISOlATION

2. DETECTION OF ANTIBODY

Because it is difficult to isolate and detect the virus. The diagnosis depends on demonstration of specific antibody to HAV in the blood.

Elisa kits are available for detecting IgM and IgG antibodies.

3. Biochemical tests

• Liver function tests such as ALT (alanine amino transferace) and bilirubin supplement for diagnosis.

HEPATITIS B

Structure• HBV is 42 nm DNA virus • It contains outer envelope

27nm diameter enclose viral genome of DNA polymerase and inner envelope

• Family - Hepadnovirdie• Genera - Orthohepadnovirus

Antigenic Structures

HBsAg

HBcAg

HBeAg

Modes of transmission

ParenteralPerinatal

Sexual

Clinical features

• Onset is slow, but severe• Incubation period varies from 6 weeks to 6 months.• Acute HBV can be divided into three phases preicteric phase icteric phase convalescent phaseCARRIERS

PROPHYLAXIS• GENERAL PREVENTIVE

MEASURES• IMMUNISATION PASSIVE IMMUNISATION :

HBIG 300-500 IUACTIVE IMMUNISATION PLASMA DERIVED VACCINE RECOMBINANT DERIVED

VACCINE

If you have never had hepatitis B,you can get 3 shots . . .

. . . and get long lasting protection.

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HEPATITIS INFECTIONS IN DENTISTRY

Questions asked

• Test for diagnosis of hepatits B infection• Pathogenicity of HBV