This document provides information about Hepatitis A virus (HAV) and Hepatitis A disease. It states that HAV is the causative agent of Hepatitis A, an acute infectious disease. The virus is transmitted primarily through the fecal-oral route. Symptoms include fever, jaundice, and fatigue. While the disease is usually self-limiting, vaccination and improved sanitation can help prevent transmission.

1. HEPATITIS “A”
DR. MAHESWARI JAIKUMAR
maheswarijaikumar2103@gmail.com

2. VIRAL HEPATITIS
• Viral hepatitis may be defined as
infection of the liver caused by
either by Hepatitis group of
viruses

3. HEPATITIS VIRUS
• Hepatitis virus A (HAV), Hepatitis
virus B (HAB), Hepatitis viruses
C,D & E are the aetiological
agents of viral hepatitis

4. VIRAL HEPATITIS

5. • In this
presentation
our focus is on
Hepatitis A,
caused by HAV

7. HEPATITIS “A”
• Hepatitis ”A”(formerly known as
“infectious hepatitis or epidemic
jaundice) is an acute infectious
disease caused by hepatitis A
virus (HAV)

8. • The disease is manifested by non
specific symptoms such as fever,
chills, headache, fatigue,
generalized weakness, aches and
pains followed by anorexia,
nausea, vomiting, dark urine and
jaundice

9. • The disease spectrum is
characterized by the occurrence
of numerous sub clinical or
asymptomatic cases
• The disease is benign with
complete recovery in several
weeks

10. • The disease is benign with
complete recovery in several
weeks

11. • Hepatitis being enterovirus
infection is endemic in most
developing countries
• In developing countries with very
poor sanitary conditions and
hygienic practices 90% children
have been affected with Hepatitis
A virus

12. • Those infected in childhood do
not experience any noticeable
symptoms.
• Epidemics are uncommon
because older children and
adults are generally immune

13. EPIDEMIOLOGICAL
DETERMINANTS

14. AGENT
• The causative
agent –
Hepatitis A is an
entero virus of
the
Picronaviridae
family. It
multiplies only
in hepatocytes

15. • Faecal shedding of the virus is at
its highest during the later part
of the incubation period and
early acute phase of illness
• Only one sero type is known

16. RESISTANCE
• The virus is fairly resistant to low
pH, heat and chemicals
• It withstands heating to 600 deg C
for one hour and is not affected by
chlorine in doses employed for
chlorination

17. • Formalin is found to be effective
disinfectant
• The virus is inactivated by UV
rays and by boiling for 5 min or
autoclaving

18. RESERVOIR OF INFECTION
• Human beings are the only
known reservoir of infection
• There is no evidence of chronic
carrier state

19. HOST FACTORS
• AGE: hepatitis A infection is
common among children.
Infection tends to be mild and
sub clinical. Clinical severity
increases with age

20. • GENDER: Both gender are equally
susceptible to infection
• IMMUNITY: Immunity after an
attack probably lasts for life
( second attacks have been
reported in 5% cases)

21. • Most individuals in endemic areas
acquire immunity thorough sub
clinical infection
• The IgM antibody appears early in
the illness and persists for over 90
days, where ass IgG appears more
slowly bad persists for many years

22. ENVIRONMENTAL FACTORS
• Cases may occur throughout the
year
• In India the disease tends to be
associated with periods of heavy
rainfall

23. • Poor sanitation and over
crowding favour the spread of
infection, giving raise to water-
borne and food-borne epidemics

24. NATURAL HISTORY OF HEPATITIS A

25. MODE OF TRANSMISSION
• The disease is transmitted
through three possible routes:
• 1. Faecal-oral route
• 2. parenteral route
• 3. sexual transmission

26. FAECAL-ORAL ROUTE
• This is the major route of
transmission
• It may occur by direct (person-to-
person) contact or indirectly by
way of contaminated water, food
and milk

27. • Water-borne transmission is the
major factor in developing
countries
• Food-borne outbreaks are
becoming more frequent

28. • Consumption of salads and
vegetables cultivated in sewage
polluted water is associated with
epidemic outbreaks of hepatitis

29. • Direct transmission comprises an
array of routes such as
contaminated hands or objects
such as eating utensils
• Direct transmission occurs
readily under conditions of poor
sanitation and overcrowding

30. PARETERAL ROUTE
• Hepatitis A is rarely transmitted
through parenteral route ( i.e. By
blood and blood products or by
skin penetration through
contaminated needles)

31. • This may occur during the stage
of viraemia. This route of
transmission is of minor
importance

32. SEXUAL TRASMISSION
• Sexual transmission may occur
mainly among homosexuals
because of oral-anal contact

33. INCUBATION PERIOD
• 10 – 50 days (usually 14-28 days)
• The length of incubation period
is directly proportional to the
dose of the virus ingested

34. CLINICAL SPECTRUM
• The onset of jaundice is
preceded by gastroenteritis
symptoms such as nausea,
vomiting, anorexia and mild
fever

36. • Jaundice may appear within few
days of the prodromal period but
anicteric hepatitis is more common
• Hepatitis A resolves completely in
98% of cases, but relapse of
symptoms may be noted in 5%
cases

38. DIAGNOSIS
• Include tests for abnormal liver
function such as serum alanine
aminotransferase (ALT) and
bilirubin, supplement the clinical
pathologic and epidemiological
findings

39. • Specific laboratory test may be
obtained by
• 1. demonstration of HAV particles
or specific viral antigens in the
faeces, bile and blood. HAV is
detected in stool from about 2
weeks prior to the onset of
jaundice, up to 2 weeks after

40. • Anti HAV appears in the IgM
fraction during acute phase,
peaking about 2 weeks after
elevation of liver enzymes
• Anti-HAV IgM usually declines to
non-detectable levels within 3-6
months

42. • Anti-HAV IgG appears soon after
the onset of disease and persists
for decades
• Thus, detection of IgM-specific
anti-HAV in the blood of an
acutely infected patient confirms
the diagnosis of hepatitis. ELISA
is the method of choice for
measuring HAV antibodies

43. PREVENTION & CONTAINMENT
• CONTROL OF RESERVOIR:
Control of reservoir is difficult
because of the following factors:
• 1. faecal shedding of the virus is
at its highest during the early
phase f the disease

44. • Low socio economic profile of
the population does not
facilitate strict isolation of cases
and carriers.
• However attention should be
paid to the usual control
measures such as complete bed
rest and disinfection of faeces
and fomites

45. • The use of 0.5% sodium
hypochlorite is strongly
recommended as an effective
disinfectant

46. CONTROL OF TRANSMISSION
• The best means of reducing the
spread of infection is by promoting
simple measures of personal and
community hygiene (hand washing
before eating and after toilet,
sanitary disposal of excreta,
purification of community water,
flocculation , filtration and
adequate chlorination.

47. • 1 mg/L of free residual chlorine
can cause destruction of the
virus in 30 min at pH values 8.5
or less
• The water treatment and
distribution system should be
improved

48. • During epidemics boiled water
should be advocated for drinking
purposes

49. CONTROL OF SUSCEPTIBLE
POPULATION
• HUMAN IMMUNOGLOBULIN :
The protective efficacy of human
immunoglobulin (Ig) against HAV
is well documented.

50. • The duration of protection is for
1-2 months and 3-5 months
following administration of IgG
at dose 0.02 and 0.06 ml/kg
body weight respectively

51. • Prophylaxis is achieved within
hours of injection & is 80-90%
effective when administered or
no later than 14 days after
exposure

52. VACCINES
• Two types of hepatitis A vaccines
are used worldwide
• 1. Formaldehyde inactivated
vaccines
• 2. Live attenuated vaccines

53. • Formaldehyde inactivated
vaccines are foe use in persons
above 1 year
• The complete vaccination
schedule consists of 2 dose
administration into deltoid
muscle

54. INACTIVATED VACCINE

55. • The interval between first
(primary) dose and second
(booster) is commonly 6-12
months
• The live attenuated vaccine is
administered as a single
subcutaneous dose

56. THANK YOU