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…