hepatitis viruses - heptatitis a, b, c, d and e, clinical features, epidemiology and lab diagnosis

HEPATITIS VIRUSES

Dr. Ashish V. JawarkarM.D. (Pathology)

Dr. Ashish Jawarkar Hepatitis viruses 2

Hepatitis Infection of liver Hepatitis viruses – A, B, C, D, E and G B – DNA virus All others – RNA viruses Cause icteric jaundice

Type A and E – food borne, feco oral route Type B and C – Blood borne, parenteral and

sexual routes


Hepatitis A

Epidemiology Clinical features Lab diagnosis Prophylaxis Treatment


Epidemiology

Common in children Feco oral route – contaminated water

or milk Over crowding and poor sanitation Ingested, reaches intestine,

penetrates epithelium, reaches liver through blood


Clinical features

2-6 weeks incubation period – asymptomatic

Clinical symptoms – malaise, anorexia, nausea, vomitting and abdominal pain

Yellow urine


Lab diagnosis

Raised bilirubin in serum (indirect>direct)

Yellow urine – bilirubin present Demonstration of antibodies by ELISA

IgM – recent infection IgG – remote infection


Prophylaxis

Improved sanitation Vaccine is available Natural infection leads to life long

immunity


Treatment

No antiviral drug available Treatment is symptomatic


TYPE B HEPATITIS

Over 350 million HBV carriers in the world

One million die anually


Epidemiology

Hepatitis B virus structure


In the serum of Hep B patients we can see – Australia antigen or


Dane particle


Developed countries

Adolscents and young adults Infection occurs through

contaminated syringes and needles Drug addicts Homosexuals


Developing countries

Children Vertical transmission from mother to

baby Horizontal transmission among

infants and neonates


Everywhere

Razors, nail clippers, acupuncture, tatooing, circumscision, ear or nose piercing

Barbers, dentists and doctors may get infected


Carriers

Those who donot have symptoms but are HbsAg positive


Screening of blood donors

Compulsory


Clinical features

No symptoms in carriers Similar to HAV in acute phase


Lab diagnosis

Demonstration of viral antibodies and antigens in serum -


HBsAg infection IgM anti HBcAg recent

infection IgG anti HBcAg remote

infection HBeAg infective Anti HBsAg immunity after

vaccination


Prophylaxis

Avoid multiple partners Avoid drug abuse Use of disposable syringes and

needles Screening of Blood, organ and semen

donors Universal immunisation (vaccination)


Immunisation - Passive

administer HBIG (Hepatitis B immunoglobulin)

Administer soon after accidental exposure

Can be administered to baby born to a carrier mother


Active immunisation - vaccine

Consists of HBsAg particles Given as a routine to all babies


Treatment

Acute phase – no treatment required, patients recover

Chronic phase – become carriers, can give antivirals like lamivudine and adefovir to keep replication in check


Hepatitis C Virus

Also blood borne Most common cause of post

transfusion hepatitis in developed countries

Most common cause of post hepatitis – hepatocellular carcinoma


Hepatitis E virus

Feco oral route Second common cause of hepatitis

after hepatitis A in developing countries

Generally mild and self limiting illness Unusually high mortality (20-40 %) in

pregnancy

hepatitis viruses - heptatitis a, b, c, d and e, clinical features, epidemiology and lab diagnosis

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