Viruses

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Viruses
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• Viruses are not a type of bacteria!
• Virus comes from the Latin word for poison.
• Viruses are so small they can only be seen with
  Electron Microscope.
• Bacteria and other cells are large enough to be
  seen with a light microscope.

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I. What is a virus?

• Non-cellular particle made up of genetic material
  (DNA or RNA) and a protein coat. Not considered
  to be living things!
• Parasites! CANNOT carry out life processes unless
  within a host (living cell). Usually host
  specific- infect only one type of host.
• Cannot reproduce on their own!

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Figure 19-15 A Lysogenic Infection
Section 19-3
a) Virus attaches and invades
c) Viral DNA separates from Cells DNA and
becomes active
Bacterial chromosome
Bacteriophage DNA
c) Cell divides
Lytic Cycle
Lysogenic Cycle
e) Cell breaks open and Releases virus
Prophage
b) Virus DNA becomes Part of Cells DNA
d) New viruses are made
Go to Section
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Figure 19-13 Virus Structures
Section 19-3
Influenza Virus
Tobacco Mosaic Virus
T4 Bacteriophage
Go to Section
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II. Viral Diseases

• A. Mostly caused by virus destroying cells in
  body.
• B. Cause human diseases such as polio, measles,
  AIDS, and the common cold
• C. CANNOT be treated with antibiotics
• D. Best Protection is prevention - Prevented by
  safe practices or Vaccine if available. (Vaccines
  must be used before infection begins)

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First Symptoms Headaches, fever, vomiting,
muscle stiffness
Later symptoms Muscle weakness, pain, loss of
reflexes progresses.
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Franklin D Roosevelt
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High fever, rash, headaches, sore throat, and
runny nose
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Rabies
Symptoms High fever, confusion, hallucinations,
difficulty swallowing, nausea, paralysis
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Bovine Spongiform Encephalopathy
Mad Cow Disease
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SARS- flu-like virus that leads to severe
pneumonia
Muscle aches, diarrhea, coughing, sneezing,
headaches, fever, fatigue,
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Ebola virus- liquification of internal organs and
severe bleed out
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Virologists

• A New Breed of Warriors

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What Is A Virologist and What Do They Do?

• A virologist is someone who studies viruses.
  These are the people who research viruses, and
  sometimes find a vaccine for them. An example of
  a vaccine that has been discovered by a
  virologist is the Influenza virus. There are
  many levels at which a virologist can work. They
  range from 0 to 4.

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What Is A Virologist and What Do They Do?
(continued.)

• At level 1, a virologist works with viruses that
  are the most common and least harmful of viruses
  like the cold virus. At level 2, are more
  dangerous strains, such as hepatitis. At level
  3, are viruses such as HIV and AIDS.

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What Is A Virologist and What Do They Do?
(continued.)

• At level 4 are the most dangerous strains such
  as Ebola, Hanta, and Marhburg. Virologists work
  with maximum protection equipment and safety
  standards. There are only 2 facilities in the
  United States with the capability of studying
  level four viruses, the CDC in Atlanta and
  USAMRIID in Maryland.

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The Choices All the things that a Virologist
can study

• Virology divides up into many sub-categories.
  Some of these include
• Biological Warfare
• Epidemology
• Lab Research
• Field Research
• Community Health Assessment
• Education and Research
• Public Health

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School

• Virologists have to go to school for many years.
  Just like any other medical profession, it is an
  on-going process. There are many subjects that a
  virologist needs to know. Chemistry,
  microbiology, molecular biology, epidemology, and
  even virology.

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Working

• Virologists can work in many different places,
  ranging from your local hospital to the Biohazard
  Level Four lab at the CDC to a remote region of
  the rainforest in Africa. Virologist can also
  find jobs working for pharmaceutical companies
  helping develop vaccines.

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Salary

• A virologists salary ranges from a little to a
  whole lot. Why? It all depends on the biohazard
  level, the amount of research done, travel, who
  they are working for, and how much research has
  been done. A virologist can make anywhere from
  30,000 to 100,000 dollars a year.

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How is a Virologist Important to the Environment?

• A virologist does contribute to the environment.
  When you see a tree with strange bumps and other
  such things, many times that is caused by a
  virus. Also, many viruses are carried by
  animals. If an animal is sick and spreading the
  disease, many times a virologist must be called
  in to try to make a vaccine so it can cure the
  disease and prevent an epidemic in both animals
  and people.

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Common Host of diseases
Finding these hosts may help with developing
vaccines.
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An ExampleMalaria

• Malaria is a disease caused by parasites and is
  lethal unless diagnosed early. Malaria is most
  common in Africa and tropical climates.
• Symptoms of malaria include fever, shivering,
  pain in the joints, headache, repeated vomiting,
  generalized convulsions and coma. Severe anaemia
  (exacerbated by malaria) is often the
  attributable cause of death in areas with intense
  malaria transmission.
• Virologists have helped eradicate this
  illness worldwide!