Viral Hepatitis Download

Transcript
VIRAL HEPATITIS
WHAT
IS “VIRAL HEPATITIS”?
Hepatitis :
An Inflammation of the Liver
Word Origin
Hepat
Itis
:::-
Greek
Liver
Inflammation
LETS BACK TRACK A LITTLE:
During the past three or more centuries “epidemic
jaundice” or viral hepatitis A has been recognised as
an important millitary disease,especially during
periods of war.Outbreaks were recorded in Germany
in 1692 and in the British Army in Flanders in
1743.Other epidemics occurred during Boer War in
South Africa and in the Japanese Navy.This trend
continued during the course of all subsequent
conflicts.
AN OUTLINE

Types : seven

Namely Hepatitis A,B,C,D,E,F and G

The causative agent can either be a DNA or
RNA virus, enveloped or non-enveloped.

The deadliest of all is Hepatitis C while
Hepatitis B is reputed to be the most infectious.


The most common : HAV,HBV,HCV.
Most of the symptoms and diagnostic
techniques are common to all types.
HEPATITIS A
 Also known as infectious hepatitis, first
identified in 1973.
 Caused by HAV non-enveloped RNA virus
 Contains a positive sense single-stranded RNA
packaged in a protein shell.
 Family
:
Picornaviridiae
 Size
:
27-32 nm in diameter
 Serotype
:
only one known type
 Genotypes
:
I, II and III
Genus
Symmetry
:
:
Hepatovirus
Icosahedral
It is :
 Only food borne disease that is preventable by
vaccine.
 Unlike Hepatitis B and C that doesn’t develop
chronic hepatitis
 Approx. 40% of all acute viral hepatitis.
TRANSMITTED BY:
 Fecal-oral route
 Unhygienic conditions
 Contaminated water or food
SYMPTOMS
NAUSEA and VOMITING:
DIARRHEA:
LOW-GRADE FEVER
LOSS OF APPETITE
TIREDNESS
RASH
JAUNDICE
DIAGNOSIS
 Blood test showing the presence of
IgM(immunoglobulin M) ; anti-HAV
in serum confirms the diagnosis of
acute hepatitis A infection.
 Elevated Liver Enzyme(liver
functioning test)
PREVALENCE
 Hepatitis A is a childhood
disease.
 Approx. 70-80 % new born
babies have HAV.
GLOBAL PREVALENCE
TREATMENT
Hepatitis A usually clears up on its own
and does not require any treatment.
However patients should:-
 Get plenty of rest.
 Avoid drinking alcohol.
 Avoid eating food enriched with fatty
acids.
 Take nutritious food.
PREVENTION
 Two vaccines:“Havrix”
“VAQTA”
 The vaccine is given in series of two shots.
 Second shot is given 6-8 months after first
shot.
 Protection starts after 2-4 weeks of first
shot
 Second shot of vaccine is for long term
protection(20 years).
HEPATITIS B
♦Also known as “SERUM HEPATITIS”
♦It is caused by enveloped DNA virus
♦Family
:
HEPADNAVIRIDAE
♦Genome
:
partially double
stranded,circular
DNA.
♦Size
:
42nm
♦Capsid Shape :
Icosahedral
♦Genotypes
:
8 i.e., A-H
♦Serotypes
:
4 i.e, adr,adw,ayr and ayw
♦ It is hundred times more infectious than
HIV.
♦ About 1/3 of the population is suffering
from Hepatitis B.
♦ Approx. 1.2 million people die each year.
♦ HBV is able to survive in dried blood for
longer than 1 week.
♦ Its virion particle is also called DANE
particle.
♦ The receptor site is still unknown
STRUCTURE
MODE OF TRANSMISSION
♦ Mainly transmitted through body fluids
such as urine,semen,vaginal fluids and
blood.
♦ Blood transfusion
♦ Reuse of needles
♦ Sexual contact
SYMPTOMS
♦ 50% of Hepatitis B patients don’t show any
symptoms.
♦ Symptoms develop within 30-180 days of
exposure to virus.
♦ It usually has flu-like symptoms.
♦ Other symptoms as mentioned for
Hepatitis A.
DIAGNOSIS
♦Blood test
♦CT scan and Ultrasound
♦Liver biopsy
TREATMENT
♦ Acute patients can recover on their own
without any treatment.
♦ For chronic patients ANTIVIRAL
MEDICATIONS are required such as:-
♦ALFA-INTERFERON:-
slows down viral ability to
liver damage.
♦LAMIVUDINE:-
inhibits viral DNA synthesis
BARACLUDE:It is the latest known anti-viral drug for the
treatment of chronic Hepatitis B that
inhibits DNA polymerase activity.
PREVENTION
♦ Hepatitis B vaccine boosts up immune system.
♦ Can be given to any age group.
♦ 3 doses for 6 months.
♦ Hepatitis B immune globulin plus Hepatitis B
vaccine combination prevents chronic Hepatitis
B in about 70% of the patients.
♦ Avoid unsanitary tattoo methods.
♦ Avoid unsanitary body piercing methods.
♦ Avoid needle stick injury.
♦ 2 billion people suffer from Hepatitis B
worldwide.
♦ 350 million are chronic Hepatitis B patients.
Presented by : Abida Jafari.
o Also known as non-A,non-B Hepatitis,
discovered in 1989.
o Causative agent
:
Hepatitis C virus,an
enveloped RNA virus.
o
Viral genome
: positive sense, single
stranded RNA
o
Family
: Flaviviridae
o
Size
: 55-65 nm
o Structure:Capsid shape
: Icosahedral
o Envelope
: lipid envelope of
cellular origin.
o Glycoproteins
: E1 and E2 are
embedded in the
lipid envelope.
o Genotype
:
o Gene codes
: HCV codes for 10
different genes.
6 but genotype 1 is
the most difficult
to treat.
MUTATION
o Evolutionary mutation i.e., different genotypes
from 1-6.
o Quasispecies: Genetic variants.
It is the mutation in a single genotype of HCV
RNA within the infected host.
o Heterogenous character is most evident in
hypervariable region 1(HVR 1) of the envelope
gene.
o Role of Heterogeneity in Quasispecies:
• viral persistence
• cellular tropism and pathogenesis of
hepatic disease
• response to antiviral therapy
STEPS INVOLVED IN
LIVER DAMAGE DURING
HEPATITIS C INFECTION
HCV
SCARRING
IMMUNE SYSTEM
CIRRHOSIS
CANCEROUS LIVER
INFLAMMATION
LIVER FAILURE
RISK FACTORS, MODE OF TRANSMISSION AND PREVENTION
o Majorly transmitted through blood
o Haemophilic majorly before 1987
o Injected drugs
o Long term kidney dialysis
o Organ transplant before July 1992
o HCV mother to child
o Tatoos,body peircing
o Sexual transmission =low
o Health care workers
SYMPTOMS
o Mostly asymptomatic but symptoms may
appear during liver cirrhosis.
o Fluid retention causing swelling of the
belly(ascites) legs or whole body.
o Persistance jaundice.
o Disturbance in sleeping.
o Vomitting with blood in it.
o Mental disturbance such as confusion,
lethargy and extreme sleepiness
o Difficult blood clotting.
TESTS AND DIAGNOSIS
o Blood screening
o ELISA
o RIBA (recombinant immunoblot assay)
o Hepatitis C RNA assay
o Liver biopsy
Note: Blood test show elevated levels of liver
enzymes, a sign of liver damage.
TREATMENT
o No vaccine available yet.
o Drugs :
combination therapy of pegylated interferon
and ribavirin.
o Different patterns of responses to antiviral treatment
Note :
Response to treatment may vary based on individual
factors,genotype,viral load. Highest response shown by
genotype 2 and 3 infected patients, least by genotype 1 and
4.
o 200 million are infected with HCV worldwide.
o In Pakistan out of 180 million about 10 million
people are infected with HCV.