CE Unit Viruses and Vaccines
DO NOT WRITE What is a virus? Have you ever had a virus? What is a vaccine? How is a virus different from bacteria?
What are the deadliest viruses? 10. Dengue fever 50 million infections per year 25,000 deaths per year epidemic in 100 countries spread by mosquitoes most common in South America and Asia
Symptoms: headache, fever, muscle pain, joint ache, rash Treatment: no vaccine, no treatment
9. Yellow Fever kills 30,000 people per year found in West Africa spread by mosquitoes
Symptoms: attacks heart, kidneys and liver chills, fever, headache, slowed heartbeat Treatment: no cure vaccine gives 10 year immunity
8. Rabies spread by dogs, bats, foxes, monkeys found in Asia, Africa, America, Europe kills 55,000 per year
Symptoms: starts with headache and fever virus infects brain and causes pain, depression and inability to swallow water Treatment: vaccine for humans and animals after infection, induced coma and medication
7. Hantavirus kills 70,000 per year spread by rodent waste
Symptoms: shock, bloodshot eyes, breathing problems, kidney problems Treatment: one form of infection has medication other form has no treatment
6. Measles has killed 200 million people in the past 150 years kills 197,000 each year spread person to person
Symptoms: runny nose, cough, fever, sores inside mouth Treatment: vaccine available after infection, medication is used
5. Hepatitis C 200-300 million people infected world wide kills 500,000 yearly most don t know they have it spread by blood contact
Symptoms: no symptoms for years eventually liver begins to fail Treatment: no vaccine treatment delays symptoms liver transplant possible
4. Influenza infects birds and mammals virus takes over cells and kills them 500,000 deaths per year
Symptoms: fever, body aches, fatigue can last 2-3 weeks worse in elderly people Treatment: vaccinations available (must be given yearly)
3. Hepatitis B has effected 1/3 of the world population 350 million people are chronic carriers kills 521,000 per year spread by blood
Symptoms: yellowing of skin and eyes, nausea, fatigue, pain can cause liver failure or cancer Treatment no treatment at first if hepatitis is chronic, drugs are available
2. Rotavirus kills 611,000 per year kills mostly children spread by food contaminated with feces
Symptoms: vomitting, diarrhea, dehydration, fever Treatment: keep fluids in the body, sometimes with an IV
1. HIV killed more than 25 million people since 1981 kills 3.1 million per year transmitted through bodily fluids
Symptoms: no symptoms at first generally develops into AIDS in 10-15 years AIDS symptoms include weight loss, respiratory infections, rashes Treatment: no vaccine or cure medication can decrease the amount of the virus in the body and prolong life
The Lytic Cycle A. Virus identifies cell and attaches to it. B. Virus injects its viral DNA or RNA C. viral DNA or RNA takes over the cell instructs the cell to begin making viruses D. New viruses are assembled inside the host cells
E. Host cell is destroyed new viruses are released and spread to new hosts examples: Ebola, flu, H1N1
The Lysogenic Cycle 1. Virus identifies cell and attaches to it. 2. Virus injects its viral DNA 3. Viral DNA or RNA becomes a part of the host DNA *Virus can lay dormant for a while. Once it becomes active, it enters and lytic cycle and begins to destroy cells examples: HIV, herpes, hepatitis
Ebola
What viruses have the highest fatality rate? 4. Smallpox infects only humans airborne virus vaccine is required in many countries symptoms: backache, bleeding, delirium
3. Marburg virus first noticed during epidemic in 1960 s infects primates (humans and monkeys) airborne virus symptoms: fever, vomiting, rash, bleeding 50% survive
2. Ebola do not know the source of the virus has only been found in Africa is NOT airborne causes internal organs to liquify only about 10% survive
1. HIV does not spread easily attacks the immune system 0% of infected people survive