Download Viruses PPT

You are to write a narrative about a
patient that has been infected with the
Ebola Virus. Tell their story….
Include:
• How was the virus contracted?
• Where (location) was the virus
contracted?
• How did the patient find out they
were infected?
• How was the diagnosis determined?
• What are the treatment options?
• How was care given to the patient?
Viruses
Lytic Cycle
In the lytic cycle, the virus takes over the hosts DNA and
grows its own. It grows its own DNA and new viruses.
The virus uses the energy of the host cell. When it is full,
the host cell explodes and releases new viruses.
Lytic Cycle
http://www.youtube.com/watch?v=wLoslN6d3Ec
The Lytic Cycle
A provirus is a DNA virus that has been inserted into a host
cell chromosome.
A retrovirus injects the enzyme, reverse transcriptase into the cell
to copy viral RNA into DNA.
HIV is a retrovirus injecting the enzyme, reverse transcriptase
into the cell to copy viral RNA into DNA.
Viruses are host specific – a protein on the surface of the virus
has a shape that matches a molecule in the plasma membrane
of its host, allowing the virus to lock onto the host cell.
HIV doesn’t target just any cell, it goes right for the cells that want to
kill it. “Helper" T cells are HIV's primary target. These cells help direct
the immune system's response to various pathogens.
HIV undermines the body's ability to protect against
disease by depleting T cells thus destroying the
immune system.
The virus can infect 10 billion cells a day, yet only 1.8
billion can be replaced daily.
After many years of a constant battle, the body has
insufficient numbers of T-Cells to mount an immune
response against infections. At the point when the
body is unable to fight off infections, a person is said
to have the disease AIDS.
It is not the virus or the disease that ultimately kills a
person; it is the inability to fight off something as
minor as the common cold.
The vaccine is administered. It contains weakened or
dead forms of the disease
1.The immune system identifies these foreign substances
(viruses and bacteria), also known as antigens.
2.Once antigens are identified, the immune system
develops proteins that circulate in the blood. These
proteins are called antibodies. They fight the infection
by killing the antigens. Antibodies are made by white
blood cells called lymphocytes, also known as B cells.
The main purpose of B cells is to create antibodies to
fight infection.
3.The body stockpiles these antibodies so they are
available to fight off the disease if exposed later on.
Unfortunately, antibodies are disease-specific, so
previously acquired chickenpox antibodies will be
useless if faced with other diseases.
• Jenner was operating on the now widely accepted
principle that once a person catches a certain
disease, he or she is immune to it for the rest of
their life. For example, once you've had the
chickenpox, it's extremely unlikely that you'll ever
catch it again. This is because your body, when
exposed again, will recognize the disease and fight it
off. The beauty of vaccines is that they help the
body develop disease-fighting abilities without
making you sick. Vaccines accomplish this amazing
feat by tricking the body into believing it already has
the full-blown disease. Here are the steps in this
process, known as the "immune response":
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Vaccine-preventable Diseases
Anthrax
Cervical Cancer
Diphtheria
Hepatitis A
Hepatitis B
Haemophilus influenzae type b
Human Papillomavirus
Influenza
Japanese encephalitis
Lyme disease
Measles
Meningococcal
Monkey pox
Mumps
Pertussis
Pneumococcal
Polio
Rabies
Rotavirus
Rubella
Shingles
Smallpox
Tetanus
Typhoid
Tuberculosis
Varicella
Yellow Fever
Source: CDC
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