Download Hepatitis and HIV

1. Identify the type of hepatitis virus causing a hepatitis infection.
2. Screen people (such as doctors, dentists, and nurses) who have
an increased chance of getting hepatitis virus infection.
3. Screen potential blood donors and donor organs to prevent the
spread of hepatitis .
4. Find out whether a person has antibodies after getting a
hepatitis vaccine .
5. Find out if a hepatitis virus infection is the cause of abnormal
liver function tests.
Hepatitis A virus
HAV
HAV causes hepatitis A (The
most common of the known
types of viral hepatitis)
A member of the
enteroviruses (picornaviridae
family).
Single -stranded RNA genome.
Have short incubation period:
2 – 6 weeks.
HAV is transmitted by fecal-oral
route.
Transmitted person-to-person by
ingestion of contaminated food or
water or through direct contact with
an infectious person.
Virus appears in the feces roughly 2
weeks before the appearance of
symptoms, so in this period the virus
is infective.
Children are the most frequently
infected group.
A tiny amount of the virus will cause the infection.
Unlike HBV, HAV is rarely transmitted via the blood, and chronic
infection doesn’t occur.
Acute, there is no chronic carrier state occurs, and there’s no
predisposition to hepatocellular carcinoma and the complications
are rarely serious.
The infection with this virus for the first time does not provide
protection from infection again.
Personal hygiene, such as careful hand washing, can minimize the
risk of the virus transmission to other person.
1. Detection of the virus in the feces only in the first 2
weeks of infection by used immune-electron
microscopy.
2. Liver function test will show elevated transaminases
(ALT, AST, LDH, ALP) and elevated measurements of
bilirubin in blood & Urine.
3. RIA or ELISA for IgM in the first 2-3 weeks and later for
IgG.
4. HAV Rapid IgM or IgG -Assay
5. Isolation of the virus in cell culture but usually not
available in the clinical laboratory.
There is no specific treatment for HAV and most
people fight off the virus naturally (self-limited),
returning to full health within a couple of
months.
The doctor will advise avoiding alcohol and fatty
foods as these can be hard for the liver to process
and may intensify the inflammation.
Patients should get plenty of rest and eat a
healthy diet.
They should also ensure they do not spread HAV
by washing their hands after using the toilet and
before preparing food.
Patients with more severe symptoms may be
monitored in hospital for a short period.
Hepatitis B virus
HBV
• Belongs to the hepadnaviridae
family.
• Spherical, double- shelled DNA
containing particles.
• Incubation period: 2 – 6 months (50
- 180 days).
Subviral lipoprotein particles (Excess
1- Vertical transmission
From mother to baby
4- Sharing contaminated
needles or other equipment
2- Sexual transmission
3- Blood transfusion
5- Parenteral transmission
By using non-sterilized equipment for tattooing,
acupuncture or body piercing
The clinical appearance of hepatitis B disease is similar to
that of hepatitis A. However, with hepatitis B, symptoms
tend to be more severe and life threatening.
1. A short, mild, flu-like illness.
2. Nausea.
3. Fatigue.
4. Abdominal pain.
5. Weight loss.
6. Jaundice.
7. Itchy skin.
If a person lives with hepatitis B infection for a number of years
then they may develop the following complications:
Chronic hepatitis.
Liver cirrhosis.
Liver cancer.
1.
Liver function tests, abnormally elevated transaminases (ALT and
AST), bilirubin, alkaline phosphatase (ALP) and lactate
dehydrogenase (LDH).
2.
The presence of HBsAg confirms diagnosis as it appears in most
patients , tested by ELISA and RIA.
3.
Serological testing via Hepatitis marker testing
4.
Detection of viral DNA load in the serum which is a strong evidence
that the infectious virions are present.
5.
Liver biopsy and PCR.
• HBs Antigen (HBsAg): Part of the virus surface. Appears
2–6 months after infection and proves that someone has acute
or chronic hepatitis B.
• If HBsAg disappears and protective antibodies appear
(HBsAg negative, anti-HBs positive), this is considered a
“cure”.
• HBs antibody (anti-HBs): The immune system creates this
antibody to destroy the HBsAg of the virus. Anti-HBs appears
if an infected person clears their virus (”cure”), or if a healthy
person is successfully vaccinated.
• HBc antibody (anti-HBc): Created by the immune system
against the core of the hepatitis B virus. Always becomes
positive in an infection and stays for life, no matter if the
infection is cleared or becomes chronic
• HBe antigen (HBeAg): can only be found in the original ”wild
type“ of the hepatitis B virus. HBeAg is an indirect sign that the
virus is replicating actively. However, HBeAg is also a vulnerable
part of the virus. The immune system might create anti-HBe
antibodies and destroy HBeAg.
This is not a cure, but the virus is being controlled by the
immune system, and cannot replicate well anymore
• HBe antibody (anti-HBe): Specialized to destroy the HBe
antigen. In chronic hepatitis B, these antibodies can damage the
virus and inhibit its
replication for many years or even decades: HBeAg negative,
anti-HBe positive. This is called HBeAg seroconversion. This is
not a cure, but the virus is at least being controlled by the
immune system.
HBsAg HBs Ab Hbe Hbe Ab HBcAb
Stage of disease
Ag
“IgM”
Incubation period
Acute hepatitis
Chronic carrier state
“low infectivity”
Chronic active state
“high infectivity”
Convalescence
Past infection
Vaccination
+
+
+
-
+/+
-
+
-
-
+
-
+
-
+
-
-
-
+
+
-
-
-
HBcAb
“Total”
+
+
+
+
+
-
Hepatitis B vaccine is pure HBsAg produced by
recombinant DNA.
 The vaccination schedule most often used for
adults and children has been three
intramuscular injections, the second and third
administered 1 and 6 months after the first.
 A blood test is taken once the course of
injections is completed to check they have
worked.
 Immunity should last for at least 5 years.

1.Acute hepatitis B

If someone is exposed to the hepatitis B virus in the
previous seven days or less, he can receive an injection of
hepatitis B immune globulin that may prevent developing
the disease.

Besides this, there is no treatment for acute hepatitis B.
Prevent further liver damage
2. Chronic hepatitis B
 Two types of treatment exist
 Interferon which is a medication administered by a
needle and
 Antiviral medicines that are taken by mouth
 These treatments do not provide a cure, but they offer
control of the virus so that further damage to your liver can
be prevented.
Regardless of wheather the infection is producing symptoms
or not, the patient will be advised to avoid alcohol, get
plenty of rest and maintain a healthy diet
Hepatitis C virus
HCV

Belong to the flaviviridae family.

Enveloped, RNA containing particles.

Incubation period: 15 – 150 days.
Transmission of hepatitis C virus is similar to hepatitis B virus,
can transmit via any activity where blood may be involved
However ; the modes of sexual transmission and passing the
virus from an infected mother to her baby via breast milk are
much less common.
Notice
Chronic infections occur in 75-85% of infected persons.
And about 20% of individuals who become infected with
HCV will clear the virus from their body within 6 months,
though this does not mean they are immune from future
infection with HCV.
1. Serological blood tests used to detect antibodies to HCV
with ELISA Technique.
This test doesn’t distinguish between an acute, chronic, or
resolved infection.
2. Using molecular nucleic acid testing methods such as :
▫ RT-PCR (polymerase chain reaction)
▫ RIBA (recombinant immunoblot assay)
• TMA (transcription mediated amplification)
▫ b-DNA (branched DNA)
These tests have the capacity to detect not only whether
the virus is present, but also to measure the amount of virus
present in the blood
(the HCV viral load).
3. The HCV viral load is an important factor in monitoring the
success to interferon-based therapy
4. Liver function tests.
5. Liver biopsy.
Hepatitis C does not always require treatment as the immune
response in some people will clear the infection, and some
people with chronic infection do not develop liver damage.
When treatment is necessary, the goal of hepatitis C treatment
is cure. The cure rate depends on several factors including the
strain of the virus and the type of treatment given.
Treatment combines the antiviral drugs interferon and ribavirin.
Notice: There is no vaccine for Hepatitis C virus.
Hepatitis D virus
HDV is unusual in that it can replicate only in cells
also infected with HBV because HDV uses HBsAg as
its envelope protein.
HBV is therefore the helper virus for HDV.
HDV is transmitted by the same means as HBV.
Hepatitis E virus
HEV is transmitted by fecal-oral route and it is a
common cause of water-borne hepatitis in many
developing countries.
Clinically the disease resembles hepatitis A.
HIV
Human Immunodeficiency Virus
Characteristics of HIV:






The causative agent of acquired
immunodeficiency syndrome
(AIDS).
Belong to the lentivirus subfamily
of the retrovidridae family.
Enveloped, icosahedral, RNA
containing particles.
Have envelope glycoproteins:
gp120 and gp41.
Infect immune system (T helper
lymphocyte; CD4).
Incubation period: 3 – 5 years.
GP 41
Transmembranous
glycoprotein
GP 120
Doking
glycoprotein
Mode of transmission of HIV:
In general, transmission of HIV follows the pattern of HBV,
except that the dose of HIV infection required to cause
infection is much higher than HBV.
 Sexual contact (primarily).
 Sharing contaminated intravenous needles.
 Infected mother to her baby, either across the placenta,
at birth, or via breast milk.
 Blood transfusions and tissue transplantation.
Signs and symptoms of HIV:



Often people who are infected
with HIV don't have any
symptoms at all.
It is important to remember
that a person who has HIV can
pass on the virus immediately
after becoming infected, even
if they feel healthy.
It's not possible to tell just by
looking if someone has been
infected with HIV
Common opportunistic infection in
AIDS:
• This is the stage of HIV infection that occurs when your
immune system is badly damaged (CD4 <200 cells/mm3)
and you become vulnerable to opportunistic infections.
• Without treatment, people who progress to AIDS typically
survive about 3 years. Once you have a dangerous
opportunistic illness, life-expectancy without treatment
falls to about 1 year.
• Antiretroviral therapy administration and a low viral
load, the patient may enjoy a near normal life span and
most likely never progress to AIDS.
Laboratory diagnosis of HIV:

Antibody detection:
• ELISAs are the most frequently used method for
screening of blood samples for HIV antibody but false
positive and false negative reactions may occur.
• Another test systems available include passive
particle agglutination, immunofluorescence, Western
blots and RIBA bioassays.
• Western blots are regarded as the gold standard

Antigen screening:
• HIV antigen can be detected early in the course of HIV
infection before the appearance of antibody.
• It is undetectable during the latent period (antigenantibody complexes are present) but become detectable
during the final stages of the infection.
• Capsid P24 antigen tests measure one of the proteins
found on HIV virus by ELISA assays.
▫ Virus isolation is accomplished by the cultivation of the
patient's lymphocytes with fresh peripheral blood cells of
healthy donors or with suitable culture lines such as Tlymphomas.
▫ However virus isolation is tedious and time consuming
(weeks), therefore virus isolation is mainly used for the
characterization of the virus.
•
This can be accomplished by PCR techniques due to its
extremely high sensitivity.
• HIV viral load in serum may be measured by assays which
detect HIV-RNA e.g. RT-PCR.
• HIV viral load has now been established as having good
prognostic value, and in monitoring response to antiviral
chemotherapy.
• Patients with a low viral load during the incubation period
had a better prognosis than those with a high viral load.
CD4 count gives an indication of the stage of disease.
Early immune deficiency CD4 count > 500 cells/mm3
intermediate immune
deficiency
CD4 count (200-500)
cells/mm3
Advance immune deficiency
CD4 count < 200 cells/mm3
“The measurement of HIV viral load tells us where the disease
is going, whereas CD4 count tells us where the disease is at this
moment”