1. The World of Viruses
What do you know?

2. What is a virus?
a microscopic particle that can infect living cells (very small – nanometres long)
can only reproduce inside a host cell
very simple in structure: a protein coat and genetic information (DNA or RNA)

3. Virus Structure Helical shape found mostly in plants
Ex. Tobacco mosaic virus
HEALTHY UNHEALTHY

4. Virus Structure Icosahedral shape are symmetrical, almost spherical
Shape of many common viruses such as the cold virus, herpes and polio
Cold virus
Polio virus

5. Virus Structure Complex (Bacteriophage)
type of virus that feeds on bacteria
reproduce by attaching to the bacterial cell and injecting genetic material into the cell

6. Infamous Viruses HANTA VIRUS
Spread through rodents, mostly deer mice in urine, droppings or saliva
Most cases have been in Southwestern states, has reached Canada seen in every province except Nova Scotia and PEI
Humans can catch the illness if they breathe in particles of the droppings, saliva or urine that are in the air

7. NORMAL
HANTA VIRUS
- notice color

8. Infamous Viruses Con’t
Machupo (Bolivian hemorrhagic fever)
villagers began to experience fever, high pain, headaches, myalgia, and hemorrhaging
10-20% of cases resulted in death

10. The local people had started to cut down thick jungles to grow corn and vegetables leading to an explosion in the mouse population in 1950s
In the early 1960s the mice began to invade the villages
Field mice carried the virus and shed it in their urine which, as it dried, was swept into the air during cleaning and was inhaled

11. Marburg Virus
A rare, severe type of hemorrhagic virus that affects humans and other primates
First diagnosed in 1967 in Marburg, Germany and Belgrade, Yugoslavia
37 fell ill after working with African green monkeys or after caring for someone infected
Passed through contact with fluid droplets, contaminated blood or tissues
Depending on the outbreak the fatality rate can range from %

12. Yellow Fever
A tropical virus that is spread to humans from infected mosquitoes
Since the 17th century it has been a major and terrifying scourge across the Americas and Africa
Starts as a fever, headache, and a sense of uneasiness, progressing within hours to chills muscle pains and vomiting
After five days, internal bleeding begins and the liver malfunctions which leads to jaundice (yellowing) of skin and eyes

13. Controlled?
Was controlled by vaccinations and widespread spraying of DDT
There has been a dramatic re-emergence of Yellow fever since the 1980s, usually as a result of changes in the ecology of an area (cutting down large stands of forests)

14. Human Immunodeficiency Virus
A virus that attacks the immune system
The infection rate is now pandemic
It has killed more than 25 million people since 1981
It is estimated that 0.6% of the world’s current population is infected
Some villages have 8 of 10 people that are HIV positive. Millions of children will be orphans as a result. Some isolated cases were found in tissue samples dating as early as 1959, but think it may date back to as early as 1930s. Thought to have originated in wild chimpanzees from Cameroon

15. Other Deadly Viruses
Ebola - related to Marburg virus, 50-90% mortality
1918 influenza virus
- caused 500,000 deaths in USA
Avian flu – the next epidemic?

16. Some other common viruses:
Chicken pox, measles, mumps
Mononucleosis
Cold, influenza
Hepatitis, genital warts, genital herpes
Rabies
Influenza virus
Rabies