epidemiology and control

1. Hepatitis A Virus
Dr. Priyamadhaba Behera
1

2. Hepatitis A Virus
World Hepatitis Day on July 28 every
year to increase awareness and
understanding of viral hepatitis
References
WHO Document, 5th edition OTPH, 18th edition Harrison principle of
medicine, Articles however applicable

3. Introduction
• Picornavirus (RNA)
• Humans are only
natural host
• Stable at low pH
• Inactivated by high
temperature,
formalin, chlorine,
boiling point for 1
minute
3

4. Introduction
•Naked RNA virus
•Related to enteroviruses,formerly known-enterovirus 72

5. Introduction
• One stable serotype only
• 4 genotypes
• Globally, there are an estimated 1.4 million cases
of hepatitis A every year
• Hepatitis A infection does not cause chronic liver
disease and is rarely fatal, but it can cause
debilitating symptoms and fulminant hepatitis
(acute liver failure)
5

6. Epidemiology

7. Country
Citation
Epidemiology-India
Year
Seroprevalence
Sample Population /
Size
Comments

8. Epidemiology-India

9. Transmission
• Primarily -faecal-oral route
• Waterborne outbreaks (infrequent) are
usually associated with sewage-contaminated
or inadequately treated water
• Close physical contact with an infectious
person not casual contact among people

10. Risk factors
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•
•
•
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Poor sanitation
Lack of safe water
Injecting drugs
Living in a household with an infected person
Being a sexual partner of someone with acute
hepatitis A infection
• Travelling to areas of high endemicity without
being immunized

11. Signs and Symptoms
• Hepatitis A infection has four clinical phases,
although these do not occur in all patients
• First stage
 An incubation period of 15 to 50 days (mean 28 to
30 days)
 Asymptomatic
 Infected person may be actively shedding the virus
in the stool

12. Signs and Symptoms
Second stage (pre-icteric )
• Several days to weeks that may precede the onset of
jaundice.
• Prodromal period is characterized by nonspecific
symptoms
• Followed by gastrointestinal symptoms such as
anorexia, nausea, vomiting, abdominal pain, fatigue,
malaise, and fever.
• Myalgia, arthralgia , cough, pharyngitis, constipation,
diarrhea, pruritus, and urticaria. Dark urine caused
by elevated bilirubin levels usually occurs prior the
onset of jaundice.

13. Signs and Symptoms
Third stage
• Characteristic yellowing of the skin and eyes of
jaundice appear
• Most symptoms subside
• Clinical signs such as hepatomegaly and hepatic
tenderness are found in about half of patients
• There is no treatment for HAV infection. Jaundice
usually resolves within a few weeks
Final stage
• Convalescent period during which the patient
recovers

14. COMPLICATIONS
• The vast majority of hepatitis A patients make a full
recovery, and the case fatality rate is low. The
estimated mortality rate is 0.1% for children less
than 15 years old, 0.3% for adults ages 15 to 39, and
2.1% for adults ages 40 and old [hollinger, 1996]
• About 15% of patients experience prolonged
jaundice and/or relapses over several months. Some
develop cholestatic hepatitis
• Fulminant (acute) liver failure -chronic liver disease
prior to onset of disease

15. Laboratory Diagnosis

16. Prevention
• Improved sanitation
• Food safety
• Immunization
Spread of hepatitis A can be reduced by
• Adequate supplies of safe drinking water
• Proper disposal of sewage within communities
• Personal hygiene practices such as regular
hand-washing with safe water

17. Hepatitis A vaccine
• Several hepatitis A vaccines are available
internationally (similar in terms protection and their
side-effects)
• No vaccine is licensed for children younger than one
year of age
• Nearly 100% of people develop protective levels of
antibodies to the virus within one month after a
single dose of the vaccine

18. Hepatitis A vaccine
• After exposure to the virus, a single dose of
the vaccine within two weeks of contact with
the virus has protective effects
• No serious adverse events
• Can be given as part of regular childhood
immunizations programmes, eg (argentina,
china, israel and the united states of america
have)
• For travellers to endemic areas

19. Hepatitis A vaccine
The vaccine for people at increased risk of hepatitis A
• Travellers to countries where the virus is endemic
• Men who have sex with men
• People with chronic liver disease (because of their
increased risk of serious complications if they acquire
hepatitis A infection)

20. Hepatitis A vaccination-India
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•
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At present there is lack of evidence for recommending
universal vaccination against hepatitis A in India1
Data from india indicate that the population is no longer
homogeneous for HAV exposure profile
Occasional outbreaks of HAV and higher proportions of
symptomatic cases are reported amongst older children and
adults from different regions of the country
The challenge is to recognize the susceptible pockets and take
pre-emptive steps
The vaccine will be useful in individuals and populations who
remain unexposed to the HAV infection during early
childhood
1.Mathur P, Arora NK.Epidemiological transition of hepatitis A in India: issues for vaccination in developing countries.Indian J
Med Res. 2008 Dec;128(6):699-704

21. Hepatitis A vaccine cost
The current cost of two paediatric doses of HAV
vaccine in india is almost 2000 INR (US$ 50), while
HAV antibody assay is available for approximately
900 INR (US$ 23) per test

22. WHO response
• Raising awareness, promoting partnerships
and mobilizing resources
• Formulating evidence-based policy and data
for action
• Preventing transmission
• Executing screening, care and treatment

23. Key facts
• Hepatitis A is a viral liver disease that can cause mild to
severe illness.
• Globally, there are an estimated 1.4 million cases of
hepatitis A every year.
• The hepatitis A virus is transmitted through ingestion of
contaminated food and water, or through direct contact
with an infectious person.
• Hepatitis A is associated with a lack of safe water and poor
sanitation.
• Epidemics can be explosive in growth and cause significant
economic losses.
• Improved sanitation and the hepatitis A vaccine are the
most effective ways to combat the disease