1. Viruses

2. What are viruses? Need a host to reproduce Not composed of cells
Do not respond to stimuli
Do not use energy for growth and development
Need electron microscope to see
Genetic Material - DNA or RNA

3. What are some examples of diseases caused by viruses?
Rabies
Influenza
West Nile Virus
Viral Meningitis
Polio
Common Cold
Zika
HPV (cancer)
AIDS/HIV
Chicken Pox
Small Pox
Yellow Fever *
Ebola
SARS
Norwalk

4. Measles
Rabies
Hepatitis
H1N1: Swine Flu
West Nile Virus
H5N1: Avian Flu

5. Bacteriophages--Viruses that attack bacteria
0.5 m

6. Viral Structure Capsid - the protein coat that surrounds the virus
Inside the capsid is either a strand of DNA or RNA
Many viruses are surrounded by an envelope (outside of the capsid) which helps them enter cells
The envelope is made up of glycoproteins (proteins attached to a carbohydrate molecule)

7. How do viruses cause Disease
Viruses release a toxin while reproducing in a hosts cell.
Viral infections generally behave in two ways:
Viruses reproduce and cause disease immediately (active or lytic) (colds, flu).
Viruses integrate into the host cell (dormant or latent) (Herpes, HIV, Shingles).

8. How are Viruses Treated
Viruses CANNOT be treated with antibiotics the way bacteria can
Vaccines use a weakened or dead version of the virus to force the body to make antibodies. These antibodies can then kill invading viruses before they can make you sick.
ROTA
Common cause of diarrhea in small children

9. How viruses are treated
Vaccines against viruses enhance the immune response of the host
Scientists are investigating methods that use viruses for treatment of diseases such as cancer and Alzheimer's disease.
The virus’ DNA or RNA are “killed” and replaced with healthy human DNA…gene replacement therapy