20.3 Bacterial & Viral Diseases
pg 586-592
Pathogen- microorganisms that cause disease
2 ways:
1. destroy living cells; tuberculosisdestroys lung tissue
2. releases a chemical that upsets
homeostasis; diphtheria, botulism
Louis Pasteur
Germ Theory of
Disease
1800’s
Bacterial Diseases:
1.
2.
3.
4.
5.
6.
TB
Diptheria
Lyme Disease
Tetanus
Strep Throat
(Bacterial) Meningitis
TB
Strep Throat
Lyme Disease
Vector?
Risk Map
Type of Bacteria?
Tetanus
Control Disease
5 ways to control1. physical removal
2. disinfectants
3. proper food storage
4. proper food processing
5. sterilization by heat
Vaccines weakened or
killed pathogen or
inactivated toxin (usually
for viral diseases)
(prevention)
Antibiotics attack bacterial
infection (treatment)
Viruses
-attack and destroy certain cells or cause
infected cells to change patterns of growth
and development
Prevention of viral diseases
-vaccines
-personal hygiene
-Cannot be treated with antibiotics, they only
kill bacteria (few antiviral drugs)
Viral Diseases:
Common Cold
Chicken Pox
Influenza
• Emerging diseases= unknown disease that
appears in a population for the first time or a
well known disease that suddenly becomes
harder to control
Little or no resistance to them, no methods of
control yet. People travel much more, so easily
spread.
MRSA, West Nile, Ebola, SARS ……..
Emerging Diseases
– This map shows locations worldwide where specific
emerging diseases have broken out in recent years.
– In recent years, new diseases, such as severe acute
respiratory syndrome (SARS) in Asia, have appeared.
At the same time, some diseases thought to be under
control have come back.
• Antibiotics kill off the bacteria with no
resistance, leaving the resistant ones behind.
These resistant bacteria reproduce.
• = “Super Bugs”
• Ex: MRSA
“Superbugs”
– An especially dangerous form of
multiple drug resistance has
recently appeared in a common
bacterium. Methicillin-resistant
Staphylococcus aureus, known as
MRSA, can cause infections that
are especially difficult to control.
–
MRSA skin infections can be
spread by close contact, including
the sharing of personal items such
as athletic gear, and are especially
dangerous in hospitals, where
MRSA bacteria can infect surgical
wounds and spread from patient to
patient.
Mad Cow Disease
Mad Cow Disease
• Prions—
– Protein infectious particles: brain problem.
Misfolded prion proteins cause normal prion
proteins to misfold; they accumulate, cells are
damaged and cease to function