Hepatitis B & C, Morphology, Modes of transmission, lab diagnosis, serological markers

1. Vishal L. Kulkarni
Dept. of Microbiology
Hepatitis B & C

2. 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.

3. Hepatitis B is Serious – Global
Impact
 It’s a common disease!
 Over 350 million people in the world have chronic
hepatitis B

4. 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.

5. 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

6. HBV structure

7. Hepatitis B virus

8. 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 .

9. 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

10. Modes of
transmission
:
Parenteral
Perinatal
Sexual

11. 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.

12. How the HBV is transmitted

13. 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.

14. 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.

15. High Moderate
Low/Not
Detectable
blood semen urine
serum vaginal fluid feces
wound exudates saliva sweat
tears
breastmilk
Concentration of Hepatitis B Virus
in Various Body Fluids

16. High risk occupational groups:
 Medical and paramedical personnel.
 Staff of blood bank
 Dialysis units
 Medical laboratories
 Mental health institutions
 Barbers and Sex workers

17. 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

18. 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

19. 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.

20. 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

21.  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

22. 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.

23. How infection occurs
 Source of infection- carriers
 Mode-

24. Lab diagnosis
 Detection of viral antigen-
 IF of blood and biopsy specimen
 Detection of nucleic acid –HCV RNA by RT-
PCR

25. Immunoblotting
 Detection of specific antibodies
 ELISA
 Recombinant immunoblot techniques
RT PCR

26.  Prophylaxis-
 No vaccine available
 General measures-
- blood screening, safe blood and safe injection
practices.

27. Thank You…