Viral hepatitis


– Several viral infections of the liver are grouped under the heading of viral hepatitis: hepatitis A, B, C, Δ (delta) and E.
– The different hepatitis viruses are present throughout the world, but their prevalence varies by country. Hepatitis A and B are common in developing countries where nearly the entire population is infected during childhood or adolescence.
– The clinical characteristics of all five diseases are similar enough to make differential diagnosis difficult; however, there are epidemiological, immunological and pathological differences. Patients with hepatitis B, C and Δ may later develop chronic liver disease or even hepatocellular carcinoma.
– The main characteristics of each type of viral hepatitis are summarized in the table below.

Clinical features

– Asymptomatic forms
Mild or anicteric forms are the most common, irrespective of the causal virus. The risk of developing later complications from hepatitis B, C and Δ are the same as for symptomatic patients.

– Classic forms
Insidious or sudden onset with symptoms of varying intensity: fever, fatigue, nausea, gastrointestinal disturbance, followed by jaundice, dark coloured urine and more or less claycoloured stool.

 Fulminant forms
Hepatocellular failure with severe, often fatal, cytolysis. This form is most frequent in hepatitis B patients with secondary infection with the Δ virus, and in pregnant women infected with hepatitis E during their third trimester (20% mortality).

– Chronic hepatitis
Hepatitis B, C and Δ may lead to cirrhosis or hepatoma.

Main profiles observed in different clinical scenarios during HBV infection

Ag
HBs

anti-HBs
antibodies

anti-HBc
antibodies

anti-HBc
IgM

Ag
HBe

anti-HBe
antibodies

HBV
DNA

Interpretation

+

(–)

(–)

+

(+)

(–)

(+)

Acute hepatitis

+/–

+

+/–

Acute hepatitis, recovery phase

+/–

+

Post-infectious immunity (cured)

+

+

+/–

+

+

Chronic hepatitis (wild virus)

+

Post-vaccination immunity

The tests in parentheses are not useful for diagnosis.
 
The various forms of viral hepatitis


Hepatitis A

Hepatitis B

Hepatitis C

Hepatitis ∆

Hepatitis E

Age group most at risk

Children

Young adults

Young adults

Young adults

Young adults

Transmission

Faecal-oral
Contaminated food and water
Transfusion (rare)

Blood and blood products
Sexual
Material contaminated with blood
Vertical (mother-to-child)

Blood and blood products
Sexual: low
Material contaminated with blood (low)
Probably vertical

Blood and blood products
Sexual
Material contaminated with blood
Possibly vertical

Faecal-oral
Contaminated food and water

Incubation period

2 to 6 weeks

4 to 30 weeks (average 10 weeks)

2 to 25 weeks

Co-infection B/∆: as for hepatitis B
Secondary infection of hepatitis B: approximately 5 weeks

2 to 8 weeks

Period of communicability

Precedes signs.
Brief: < 10 days after the appearance of jaundice
Most infectious at the end of incubation period.

Precedes signs and lasts entire active period. Can persist in chronic carriers.

Precedes signs.
Duration is not well known, probably the same as for hepatitis B. Could persist beyond normalisation of transaminases.

Precedes signs.
Duration is not well known, probably the same as for hepatitis B.

Precedes signs.
Duration is not well known (10 to 15 days after the appearance of jaundice)

Fulminant forms

0.2 to 0.4%

1 to 3%

More rare than in hepatitis B

Much more common in patients with secondary infection of hepatitis B than in patients with B/∆ co-infection

20% mortality in pregnant women

Prognosis

No chronic forms

Chronicity: 0.2 to 10% of which 5 to 15% progress to cirrhosis.
Hepatoma possible

Chronicity: up to 50%, of which 10 to 25% progress to cirrhosis.
Hepatoma possible

Chronicity: 2 to 5% for patients with B/∆ co- infection; > 90% if secondary infection of hepatitis B (rapid cirrhosis)

No chronic forms

Individual prevention

Polyvalent immunoglobulin

Specific anti-HBs immunoglobulin
Safe sex (condoms)

Specific anti-HBs immunoglobulin may be effective

As for hepatitis B (the ∆ virus can only develop with B)

Does not exist

Vaccination

Anti-hepatitis A

Anti-hepatitis B

Does not exist

Anti-hepatitis B

Does not exist

Collective prevention Hygiene, sanitation

Limit transfusion, screen blood prior to transfusion
Single use of disposable material

Hygiene, sanitation

Treatment

– Rest, hydration, no special diet.
– Drug therapy for symptomatic treatment (analgesics, antipyretics, antidiarrhoeals, antiemetics etc.) during the acute phase is contra-indicated as it may aggravate symptoms and the evolution of hepatitis. Corticosteroids are not indicated.

Vaccination

Only against hepatitis A and B. Vaccination against hepatitis B is included in the EPI of some countries.

IM vaccination against hepatitis B:

– Standard schedule
• Newborns, infants
In countries where perinatal infection is common: one injection after birth, then at 6 and 14 weeks
Where perinatal infection is less common: one injection at 6, 10 and 14 weeks
• Children, adolescents, adults
Schedule 0-1-6: 2 injections 4 weeks apart, then a 3rd injection 5 months after the 2nd injection

– Accelerated schedule, when rapid protection is required (imminent departure in highly endemic areas, post-exposure prophylaxis)
Schedule D0-D7-D21: 3 injections administered during the same month, then a 4th injection one year after the 1st injection