Hepatitis is an inflammation of the liver that can be caused by viruses or other factors. There are five main hepatitis viruses: Hepatitis A, B, C, D, and E. Hepatitis B and C cause chronic liver disease and put people at high risk for cirrhosis and liver cancer. Hepatitis B is diagnosed through blood tests detecting antigens and antibodies. Treatment involves antiviral medication lasting 6 months to a year. Hepatitis C is diagnosed through blood tests detecting antibodies and RNA. New antiviral drugs can cure most cases of Hepatitis C infection within 12 weeks of treatment. There are vaccines to prevent Hepatitis A and B but currently no vaccine for Hepatitis C.
3. Definition of hepatitis:
Hepatitis is an inflammation of the liver,
the condition can be self-limiting or can
progress to fibrosis (scarring), cirrhosis or
liver cancer.
8. RISK OF TRANSMISSION:
Risk of transmission mainly depend on:
Environmental
Viability (ability to
survive outside the
human body)
Frequency of the
disease occurring
in population
Viral load
Number of viruses
in patient’s blood
9. DIRECT INFECTION
through a cut on the skin
(percutaneous), as a result of:
An accidental bite by the
patient during a dental
procedure.
Needle wound during an
anesthetic procedure.
Cut with a sharp object such as
a scalpel blade.
INDIRECT INFECTION
Aerosols of saliva.
Gingival fluid.
Natural organic particles
(dental caries tissue) mixed
with air and water.
e.g. blood splash to the eye.
13. HEPATITIS B VIRUS
Prevalence:
The world can be divided into three areas where
the prevalence of chronic HBV infection is:
High (>8%), Intermediate (2-8%), and Low (<2%).
Egypt is of intermediate endemicity (2–8%),
nearly 2-3 million Egyptians are chronic carriers.
14. HEPATITIS B VIRUS
Incubation period:
Symptoms begin an average of 90 days
(range: 60–150 days) after exposure to HBV.
Diagnosis: (serology)
Detection of hepatitis B virus infection involve serum
or blood tests that detect either viral antigens (proteins
produced by the virus) or antibodies produced by the
host.
15. HEPATITIS B VIRUS
Diagnosis: (serology)
• indicating infectious person.
• Used to make hepatitis B vaccine.(HBsAg)
• Indicating recovery and immunity.
• In successfully vaccinated person.(anti-HBs)
• Indicating replicating virus.
• Person has high level of HBV.(HbeAg)
16. HEPATITIS B VIRUS
Treatment:
Acute hepatitis B infection does not usually require
treatment as most adults clear the infection
spontaneously.
Treatment of chronic infection may be necessary to
reduce the risk of cirrhosis and liver cancer.
Treatment lasts six months to year depending on
medication and genotype.
Antiviral drugs lamivudine (Epivir), adefovir (Hepsera).
17. HEPATITIS B VIRUS
Vaccination:
Vaccine by 3 injections : 1st dose at base line, 2nd dose
after one month, 3rd dose after 6 months from 1st and
post vaccination (anti-HBs) antibody level one month
later if:
>100 IU/l ---Responder (85%-90% of individual)
10-100--- poor responder (need booster)
<10 ---non responder (repeat vaccination)
21. HEPATITIS C VIRUS
Prevalence:
About 170 million people are
living with HCV infection.
the prevalence is reported to be
the highest (approximately 10%) in
Egypt.
22. HEPATITIS C VIRUS
Incubation period:
The incubation period for hepatitis C virus
is (2 weeks to 6 months).
The average time period from exposure to
symptom onset is 4–12 weeks
(range: 2–24 weeks).
23. HEPATITIS C VIRUS
Diagnosis:
Several blood tests are performed to test for HCV infection,
including:
Screening tests for antibody to HCV (anti-HCV)
Qualitative tests to detect presence or absence of virus (HCV
RNA polymerase chain reaction [PCR])
Quantitative tests to detect amount (titer) of virus (HCV RNA
PCR)
24. HEPATITIS C VIRUS
Treatment:
Therapy based on interferon and ribavirin, which required weekly
injections for 48 weeks, cured approximately half of treated patients,
but caused frequent and sometimes life-threatening adverse
reactions.
Recently, new antiviral drugs have been developed.
These medicines, called direct antiviral agents (DAA) are much more
effective, safer and better-tolerated than the older therapies.
Therapy with DAAs result can cure most persons with HCV infection
and treatment is shorter (usually 12 weeks) and safer.