this presentation about hepatitis A and B

1. Submitted by
M.Narayani
II Msc Microbiology

2. HEPATITIS Hepatitis is an inflamation of
liver
The condition can be self-
limiting or can progress to
fibrosis cirrhosis or liver cancer
Hepatitis viruses are mostly
cause hepatitis but other
infection ,toxic
substance[eg.alcohol,certain
drugs],auto immune diseases can
also cause hepatitis
A heterogeneous group of
viruses called hepatotrophic
viruses cause viral hepatitis and
damage to liver

3.  Hepatitis A virus
 Hepatitis B virus
 Hepatitis C virus
 Hepatitis D virus
 Hepatitis E virus

4. These 5 types are of greatest concern
because of the burden of illness &
death they cause & potential for
outbreaks & epidemic spread
Hepatitis A & E are typically caused by
ingestion of contaminated food or
water
Hepatitis B,C,D occurs as a result of
parental contact with infected body
fluids
Also transmission from recepient of
contaminated blood or blood
products,mother to baby,family
members to child & sexual contact

5.  Hepatitis type A is a subacute diseaseof global
distribution
 Mainly occurs in children and young adults
 The term “infectious hepatitis” was coined in
1912
 HAV was first demonstrated by Feinstone and
co-workers during the year 1973
 It is a 27 nm non-enveloped,symmetrical (+)
RNA, with icosahedral symmetry
 Its characters mimic picornavirus family
 It is non-cytopatheic when grown in cell culture
 The HAV genome comprises about 7500
nucleotides
 It can withstand 60⁰c for 1 hour and 100⁰c for 1
min
 The virus is inactivated by formaldehyde &
chlorine
 It is not affected by non-ionic detergents
 It survives at 4⁰c or even much coolar
temperatures

6. VIRUS
ENTERS
THROUGH
FOOD &
WATER
REPLICATES
IN
INTESTINAL
EPITHELIAL
CELLS
RELEASE
BLOOD AND
REACH
LIVER
SYMPTOMS
RELEASE TO
INTESTINE
THROUGH
BILE
RELEASE
THROUGH
FAECES

7.  Isolation of virus in tissue
culture requires prolonged
adaptation
 Immunoelectron
microscopy
 Complement fixation
 Immune adherence
haemagglutination
 Radioimmunoassay
 Enzyme immunoassay

8.  Improvement of
sanitation
 Prevention of faecal
contamination
 Prevention of direct
contact with infected
individuals
 Inactivated vaccine
through intramuscular
route

9.  Attenuated vaccine 
administrated orally
 Consumption of water from
safe water sources
 Avoidance of uncovered
food or beverages from
street vendors
 Avoidance of fruits,
salads,or un cooked
vegetables that have not
been washed or treated in
boiled water.

10. HEPATITIS B VIRUS
 HBV cause a type of hepatitis
called serum hepatitis
 It is an important cause of
acute and chronic infection of
liver
 HBV infection cause more than
million deaths per year
 In 1965,Blumberg reported
protein antigen in the serum of
an Australian patient
 This antigen was called
Australian antigen
 This was found to be hepatitis
surface antigens (HBsAg)

11.  HBV is a 42-nm spherical virus
 There are three envelope
polypeptides that are called as
HBsAg, HBcAg, and HBeAg
 HBV belongs to the family
Hepadnaviridae
 The nucleocapsid of the virion
consists of the viral genome
surrounded by the core antigen
 The virus is stable at 37⁰c for 60
min
 The virus does not grow in tissue
culture medium

12. VIRUSE ENTRY
FINDS TARGET
CELL
ENTERS INSIDE
OF
HEPATOCYTE
REPLICATION
MATURATIONASSEMBLY
VIRUS RELEASE
CYTOPATHEIC
EFFECT
SYMPTOMS

13.  Several type of blood tests
are recommended for
diagnosis of hepatitis
 Liver enzyme test
 Blood levels of liver enzymes
 Detection of hepatitis B
antigens
 ELISA test

14.  Prevention is possible by
active and passive
immunization
 Two types of vaccine
 Recombinant HB vaccine
synthesized from yeast cells
 Plasma –derived vaccine
 A booster dose is
recommented at 5 years of
age

15.  HBV are treated with
interferon
 It blocks the entry of virus
into the cells
 In recent years interferon is
prescribed in combination
with ribavirin
 Interferon stimulates the
body’s natural defence
 During IFN treatment, the
following side effects are
observed:
 Bodyaache,fatigue,diarrhoea,
nausea,discomfort,loss of
appetite

16. Medical microbiology
S.Rajan
BJP Publishers
www.who.int/features/qa/76/en/