Viral hepatitis refers to a group of infectious diseases that affect the liver caused by different hepatitis viruses (A, B, C, D, E). Hepatitis A is typically transmitted through contaminated food or water and usually does not lead to chronic infection. Hepatitis B is transmitted through contact with infected blood or bodily fluids and can lead to chronic infection. Hepatitis C is mainly spread through contact with infected blood, often through sharing needles. Hepatitis D only affects those with Hepatitis B infection and is transmitted through blood or bodily fluids. Hepatitis E is often spread through contaminated water in areas with poor sanitation.

1. VIRAL HEPATITIS

2. INTRODUCTION
1. Viral hepatitis refers to a group of infectious
diseases that affect the liver, causing
inflammation and potentially leading to various
liver-related health issues. These infections are
primarily caused by several different viruses,
each categorized by a specific letter (A, B, C, D,
and E), with each type having unique
characteristics and modes of transmission.

3. DEFINITION
Viral hepatitis is an infection that
causes liver inflammation and damage.

4. TYPES
1.Hepatitis A(HAV): Typically transmitted
through contaminated food or water, this
type of hepatitis usually results in acute
illness but rarely leads to chronic hepatitis.

5.  2.Hepatitis B (HBV): Transmitted through
contact with infected blood, sexual
contact, or from mother to child during
childbirth.

6.  3.Hepatitis C (HCV): Mainly spread through
contact with infected blood, often through
sharing needles or other drug paraphernalia

7.  4.Hepatitis D (HDV): A rare form that only
affects individuals with Hepatitis B and is
transmitted through contact with infected
blood or other body fluids.

8.  3.Hepatitis E (HEV): Often spread through
contaminated water, especially in areas
with poor sanitation.

9. EPIDERMOLOGICAL FACTORS

10. AGENT
 ) RESERVOIR OF INFECTION: The human cases are the only reservoir of
infection.
 ) PERIOD OF INFECTIVITY: The risk of transmitting HAV is greatest from
2 weeks before to 1 week after the onset of jaundice.
 ) INFECTIVE MATERIAL: Mainly man’s faeces.
 ) VIRUS EXCRETION: HAV is excreted in the faeces for about 2 weeks
before onset of jaundice and for up to 2 weeks thereafter.

11.  > Host factors

 a) AGE: Infection with HAV is more frequent among
children than in adults. However, people from all ages
may be infected if susceptible.
 B) SEX: Both sexes are equally susceptible.
 C) IMMUNITY: Immunity after attack probably lasts for
life.


12. ENVIRONMENTAL FACTORS
occur throughout the year.
■ In India the disease tends to be associated with
periods of heavy rainfall.

13. INCUBATION PERIOD
10-50 days (usually 25 to 30 days).

14. MODE OF TRANSMISSION
A) FAECAL-ORAL ROUTE: Major route of
transmission. –By contaminated water, food or milk.
B) PARENTERAL ROUTE (Rarely):
-By blood and blood products or by skin penetration
through contaminated needles.
C) SEXUAL TRANSMISSION:
-May occur mainly among homosexual men because
of oral-anal contact.

15. PATHOPHYSIOLOGY

16. DIAGNOSIS
1. Demonstration of Virus in feces, blood, bile: By:
Immunoelectron microscopy
2. Virus Isolation:
3. Detection of Antibody :By ELISA
4. Biochemical tests:
i) Alanine aminotransferase (ALT)
ii) Bilirubin
iii) Protein
5. Molecular Diagnosis: RT PCR of feces