all information about it include :- 1- DEFINITION 2- SIGNS AND SYMPTOMS 3- MECHANISM 4- RISK FACTOR 5- COMPLICATIONS 6- PRECAUTION 7- PREVENTION 8- EPIDEMIOLOGY 9- TREATMENT and finally video about the mechanism of action if you van not open it hit this link https://www.youtube.com/watch?v=ZuUfGeoN_cw i hope it meet what you want

1. -Omar Ali Saad Mansour
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2. Definition
Hepatitis B is an infectious disease caused
by the hepatitis b virus (HBV) which affects
the liver. It can cause both acute and chronic
infection . Many people have no symptoms
during the initial infection.

3. The virus is transmitted by exposure to
infectious blood or body fluids. infection around
the time of birth or from contact with other
people's blood during childhood is the most
frequent method by which hepatitis B is
acquired in areas where the disease is common.
In areas where the disease is rare, IV drug
use and sexual intercourse are the most
frequent routes of infection.

5. High Moderate
Low/Not
Detectable
blood semen urine
serum vaginal fluid feces
wound exudates saliva sweat
tears
breastmilk
Concentration of Hepatitis B Virus
in Various Body Fluids

6. Signs and Symptoms
ranging from mild to severe, usually appear about one
to four months after you've been infected Signs and
symptoms of hepatitis B may include:
- Abdominal pain - Dark urine
- Fever - Joint pain
- Loss of appetite - Nausea and vomiting
- Weakness and fatigue
- Yellowing of your skin and the whites of your eyes
(jaundice)

7. Causes
Hepatitis B infection is caused by the hepatitis B virus
(HBV). The virus is passed from person to person
through blood, semen or other body fluids.
Common ways HBV is transmitted include:
Sexual contact. You may become infected if you
have unprotected sex with an infected partner
whose blood, saliva, semen or vaginal
secretions enter your body.

8. Sharing of needles. HBV is easily transmitted through
needles and syringes contaminated with infected blood.
Sharing intravenous (IV) drug paraphernalia puts you at high
risk of hepatitis B.
Accidental needle sticks. Hepatitis B is a concern for
health care workers and anyone else who comes in contact
with human blood.
Mother to child. Pregnant women infected with HBV can
pass the virus to their babies during childbirth. However, the
newborn can be vaccinated to avoid getting infected in
almost all cases. Talk to your doctor about being tested for
hepatitis B if you are pregnant or want to become pregnant.

9. Mechanism
The virus mainly affects liver function. It invades the
liver cells (hepatocytes) and uses the cells’ machinery
to replicate within it. The hepatitis B virion binds to the
hepatocyte via the preS domain of the viral surface
antigen. The cell then engulfs the virus in a process
called endocytosis.
As the infection occurs, the host immune response is
triggered. The body’s immune system attacks the
infected hepatocytes, which leads to liver injury at the
same time as clearing the virus from the body.

10. The liver damage associated with HBV
infection is mainly caused by the adaptive
immune response, particularly the virus-
specific cytotoxic T lymphocytes (CTLs).
These CTLs kill cells that contain the virus.
Liver damage is also aggravated by the
antigen-nonspecific inflammatory cells and
activated platelets at the site of infection.

12. Acute vs. chronic hepatitis B
Hepatitis B infection may be either short-lived (acute) or
long lasting (chronic).
Acute hepatitis B infection
lasts less than six months. Your immune system
likely can clear acute hepatitis B from your body,
and you should recover completely within a few
months. Most people who acquire hepatitis B as
adults have an acute infection, but it can lead to
chronic infection.

13. Chronic hepatitis B infection
lasts six months or longer. When your immune system
can't fight off the acute infection, hepatitis B infection
may last a lifetime, possibly leading to serious illnesses
such as cirrhosis and liver cancer.
The younger you are when you get hepatitis B —
particularly newborns or children younger than 5 — the
higher your risk the infection becoming chronic.
Chronic infection may go undetected for decades until a
person becomes seriously ill from liver disease.

14. Investigation
A- serology :
1- HBsAg
2- antibody to HBsAg ( anti-HBs )
3- HBcAg
4- antibody to HBcAg ( anti-HBc )
5- HBeAg

15. B- viral load :
* HBV-DNA can be measured by PCR
In the blood .
* Measurement of viral load is
important in monitoring antiviral therapy .

16. Prevention and precautions of
HBV

17. prevention
- Hepatitis B vaccine can prevent hepatitis B.
- It is the first anti-cancer vaccine because it can
prevent a form of liver cancer
(hepatocarcinoma).

18. Who should get hepatitis B vaccine
and when?
- Everyone 18 years of age and younger
- Adults over 18 who are at risk

19. Adults who are at risk for HBV
infection
- Household contacts of persons with chronic HBV
infection
- Sex contacts of infected people
- People who have more than one sex partner in 6
months
- People who inject illegal drugs
- Heath care and public safety workers who might be
exposed to infected blood or body fluids
- Hemodialysis patients

20. doses of hepatitis B vaccine
* Infant whose mother is infected with HBV:
- First Dose: within 12 hours of birth
- Second Dose: 1 - 2 months of age
- Third Dose: 6 months of age

21. * Infant whose mother is NOT infected with HBV:
- First Dose: between birth – 2 months of age
- Second Dose: 1 - 4 months of age
(at least 1 month after first dose)
- Third Dose: 6 - 18 months of age
(at least 2 months after the second dose)

22. Emergency hepatitis B vaccination
- In some situations, you may also need to
have an injection of antibodies called specific
hepatitis B immunoglobulin (HBIG) along with
the hepatitis B vaccine.
- HBIG should ideally be given within 48 hours,
but you can still have it up to a week after
exposure.

24. Risks of hepatitis B vaccine
- Severe allergic reactions, harm or death
(extremely rare)
- Soreness at site of injection lasting 1-2 days
- Mild to moderate fever

25. What if there is a moderate or severe
reaction?
What is an allergic reaction?
- Hives, swelling, redness
- High fever
- Difficulty breathing, wheezing
- Dizziness
- Unusual behavior
When to expect an allergic reaction?
- Within a few minutes to a few hours after the shot
What should I do?
- CALL a doctor or see a doctor right away
- TELL your doctor what happened, and when the vaccination was given

26. precautions
- A common set of infection-control strategies
should be effective for preventing hepatitis B.
MEDICAL HISTORY:
Always obtain a thorough medical history.
Include specific questions about medications,
current illnesses, hepatitis.

27. PROTECTIVE ATTIRE AND BARRIER
TECHNIQUES
For protection of personnel and patients:
1-when touching blood, saliva, or mucous membranes . Gloves must be worn
when touching blood-soiled items, body fluids, or secretions, as well as surfaces
contaminated with them. Gloves must be worn when examining all oral lesions.
2. Surgical masks and protective eyewear or face shields must be worn when
splashing or spattering of blood or other body fluids is likely, as is common in
dentistry.
3. Reusable or disposable gowns, laboratory coats, or uniforms must be worn
when clothing is likely to be soiled with blood or other body fluids.
4. Impervious-backed paper or clear plastic wrap may be used to cover surfaces
that may be contaminated by blood or saliva and that are difficult or impossible to
disinfect. The coverings should be removed and replaced between patients.
5. All procedures and manipulations of potentially infective materials should be
performed carefully to minimize the formation of droplets, spatters, and aerosols
such as rubber dams.

29. Hand washing
Hands must always be washed between patient
treatment contacts (following removal of gloves).

30. CARE OF SHARP INSTRUMENTS AND
NEEDLES
1-Sharp items (needles, scalpel blades, and other sharp
instruments)
should be considered as potentially infective and must be
handled with extraordinary care to prevent unintentional
injuries.
2. Disposable syringes and needles, scalpel blades, and other
sharp items must be placed into puncture-resistant containers
.
3. Recapping of a needle increases the risk of unintentional
needlestick injury. One hand scope technique should be used .
4. A new (sterile) syringe and a fresh solution should be used
for each patient.

32. Epidemiology
* Worldwide, HBV is the primary cause of
liver cancer.
- For males, it is the third leading cause of cancer
mortality
- For females, it is the sixth leading cause of
cancer mortality

33. - An estimated 800,000–1.4 million persons in the
United States have chronic HBV infection.
- Chronic infection is an even greater problem globally,
affecting approximately 350 million persons.
- An estimated 620,000 persons worldwide die from
HBV-related liver disease each year.
Hepatitis B

34. -The incubation period from the time of exposure
to onset of symptoms is 6 weeks to 6
months.
- HBV is found in highest concentrations in blood
and in lower concentrations in other body fluids
(e.g., semen, vaginal secretions, and wound
exudates).
- HBV infection can be self-limited or chronic.
Hepatitis B

35. Hepatitis B
In adults, only approximately half of newly
acquired HBV infections are symptomatic, and
approximately 1% of reported cases result in
acute liver failure and death.

36. Symptomatic Infection
Chronic Infection
Age at Infection
Chronic Infection (%)
SymptomaticInfection(%)
Birth 1-6 months 7-12 months 1-4 years Older Children
and Adults
0
20
40
60
80
100100
80
60
40
20
0
Outcome of Hepatitis B Virus Infection
by Age at Infection
ChronicInfection(%)

37. Possible Outcomes of HBV Infection
Acute hepatitis B infection
Chronic HBV infection
3-5% of adult-acquired
infections
95% of infant-
acquired infections
Cirrhosis
Chronic hepatitis
12-25% in 5 years
Liver failureHepatocellular
carcinoma
Liver transplant
6-15% in 5 years 20-23% in 5 years
DeathDeath

38. Complications
Scarring of the liver (cirrhosis). The inflammation
associated with a hepatitis B infection can lead to extensive
liver scarring (cirrhosis), which may impair the liver's ability
to function.
Liver cancer. People with chronic hepatitis B infection have
an increased risk of liver cancer.
Liver failure. Acute liver failure is a condition in which the
vital functions of the liver shut down. When that occurs, a
liver transplant is necessary to sustain life.
Other conditions. People with chronic hepatitis B may have
kidney disease, inflammation of blood vessels or anemia.

39. Treatment and Drugs
Treatment to prevent hepatitis B infection after
exposure
If you know you've been exposed to the hepatitis B virus,
call your doctor immediately. If you haven't been
vaccinated or aren't sure whether you've been
vaccinated or whether you responded to the vaccination,
receiving an injection of hepatitis B immune globulin
within 12 hours of coming in contact with the virus may
help protect you from developing hepatitis B. You should
be vaccinated at the same time.

40. Treatment for acute hepatitis B infection
If your doctor determines your hepatitis B
infection is acute — meaning it is short-lived
and will go away on its own — you may not
need treatment. Instead, your doctor might
recommend rest and adequate nutrition and
fluids while your body fights the infection.

41. If you've been diagnosed with chronic hepatitis B
infection, you may have treatment to reduce the
risk of liver disease and prevent you from passing
the infection to others. Treatments include:
Antiviral medications.
Several antiviral medications — including lamivudine
(Epivir), adefovir (Hepsera), telbivudine (Tyzeka) and
entecavir (Baraclude) — can help fight the virus and slow
its ability to damage your liver. Talk to your doctor about
which medication might be right for you.
Treatment for chronic hepatitis B infection

42. Interferon alfa-2b (Intron A).
This synthetic version of a substance produced by the
body to fight infection is used mainly for young people
with hepatitis B who don't want to undergo long-term
treatment or who might want to get pregnant within a
few years. It's given by injection. Side effects may include
depression, difficulty breathing and chest tightness.
Liver transplant.
If your liver has been severely damaged, a liver transplant
may be an option. During a liver transplant, the surgeon
removes your damaged liver and replaces it with a
healthy liver. Most transplanted livers come from
deceased donors, though a small number come from
living donors who donate a portion of their livers.
Other drugs to treat hepatitis B are being developed.