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Vishal L. KulkarniDept. of Microbiology
Hepatitis B & C
Hepatitis B
It is a liver disease caused by the hepatitis B
virus (HBV).
It ranges in severity from a mild illness,
lasting a few weeks (acute), to a serious long-
term (chronic) illness that can lead to liver
disease or liver cancer.
Hepatitis B is Serious – Global Impact
It’s a common disease!Over 350 million people in the world have
chronic hepatitis B
HBV classification and morphology :
Family -Hepadnaviridae.
Genus- Orthohepadnavirus
42 nm DNA virus with outer envelope and
inner core.
Blumberg in 1965 discovered , named as
Australia antigen.
Later it was found to be surface component of
HBV. Hence named as hepatitis B surface
antigen (HBsAg).
Morphology ….
Spherical particles 22 nm in diam.
Filamentous or tubular 22 nm
with varying length
Called as HBs Ag surface components which are
produced in excess.
Third type double walled spherical structure 42 nm
diameter called as Dane particle
HBV structure
Hepatitis B virus
Epidemiology: Natural infection occurs only in humans.No animal reservoir.Virus is maintained in large pools of carrier.Usually occur as sporadics. Occasional outbreaks occur in hospitals,
orphanages and institutions for mentally handicapped.
India falls in intermediate group: carrier rate 2-7%. High in southern part of India .
Carrier : - Person with detectable HBsAg in blood for more than six months.
Super carrier: - High titres of HBsAg+HBeAg+ DNA polymerase +HBV in circulation.
- Elevated transaminases. Highly infectious.Simple carrier:
- Low titres of HBsAg - Negative for HBeAg, DNA polymerase ,HBV. Low infectivity
Modes of transmission :
Parenteral
Perinatal
Sexual
Parenteral: Blood and blood products of carrier and patients.HBV is highly infectious than HIV.0.00001 ml can be infectious..!
Objects like shared syringes, needles, sharp items, endoscopes, razors, nail clippers ,combs, accupunture, ritual circumcision.
Direct contact with skin lesions like eczema, pyoderma and scratches.
How the HBV is transmitted
Perinatal:
Quite common from carrier mother to baby. If mother HBeAg positive – high risk (60-
90%)If mother HBeAg negative- low risk (5-15%)Infection usually acquired during birth.
Sexual: more common in developed countries,
particularly in promiscuous homosexuals.Can also occur by artificial insemination.
Saliva ,breast milk, semen, vaginal secretion ,urine, bile and feces also contains virus.
High ModerateLow/Not
Detectable
blood semen urineserum vaginal fluid feces
wound exudates saliva sweattears
breastmilk
Concentration of Hepatitis B Virus in Various Body Fluids
High risk occupational groups:
Medical and paramedical personnel.Staff of blood bankDialysis units Medical laboratories Mental health institutionsBarbers and Sex workers
LAB DIAGNOSIS:
Serological demonstration of viral markers :
HBsAg :first marker to appear in the blood.Being detectable in blood even before onset
of clinical illness.Disappears in 2 months. Then anti-HBs appears.
Presence of anti-HBsAg alone indicates vaccination
Symptoms
HBeAg anti-HBe
Total anti-HBc
IgM anti-HBc anti-HBsHBsAg
0 4 8 12 16 20 24 28 32 36 52 100
Acute Hepatitis B Virus Infection with Recovery Typical Serologic Course
Weeks after Exposure
Titre
18
HBcAg: Not demonstrable in circulation.Antibody appears after 1-2 wk of appearance HBsAg.Earliest antibody marker to be seen in blood. IgM anti- HBc: acute infection IgG anti- HBc: remote infection HBeAg: Appears concurrently with HBsAg.Indicator of active intrahepatic viral replication. Its presence denotes high infectivity.
Prophylaxis :
Avoiding risky practices like promiscuous sex, injectable drug abuse, direct or indirect contact with blood, semen or other body fluids of
patients and carrier.Use of disposable syringes, needles.Screening of blood, semen and organ donors.Health education Immunization : Best method
Passive Immunisation-
HBIG (0.5 ml IM)
Active Immunisation-
HBsAg Vaccine (0.5 ml IM ; 0, 1 and 6 month)
Post exposure prophylaxis-
HBIG 300-500IU, within 48 hrs
Full course of vaccination
Hepatitis C Virus
HCV is small (50-60 nm) virus with single
stranded RNA.
Enveloped virus- carrying
glycoprotein spikes
Shows considerable genetic and
antigenic diversity.
Has not been grown in culture, but cloned in
E.coli.
How infection occursSource of infection- carriersMode-
Lab diagnosis
Detection of viral antigen-
IF of blood and biopsy specimen
Detection of nucleic acid –HCV RNA by
RT-PCR
Immunoblotting
Detection of specific antibodies
ELISA
Recombinant immunoblot techniques
RT PCR
Prophylaxis-
No vaccine available
General measures-
- blood screening, safe blood and safe injection
practices.
Thank You…