Transcript communicable diseases - Southwest High School

COMMUNICABLE DISEASES
UNDERSTANDING INFECTIOUS
DISEASES
LEARNING TARGETS
• I can describe 6 different types of microorganisms that cause communicable diseases.
• I can describe 4/5 ways in which infectious
diseases are spread.
---------------------------------------------------------------Resource: Text: Ch. 25, pages 628 – 636
Big Idea
• Communicable diseases are transmitted in a
variety of ways.
• Steps can be taken to prevent infection.
Key Concepts:
• What are microorganisms that cause disease?
• How diseases are spread …
• Prevention strategies of communicable
diseases …
• Respiratory infections
• Treatment and drugs
• Caring for the immune system
FORMATIVE QUESTIONS YOU WILL BE ABLE
TO ANSWER AT THE END OF THIS UNIT
1. DEFINE THE WORD COMMUNICABLE
2. LIST common communicable diseases
………………………………………………………………………….
Compare and Share with your neighbor
Formative Questions … continued
Copy these questions in your note book. Leave
space to answer each question.
3. How is a virus different from bacteria?
4. How is a common cold different from the flu?
5. What are 3 ways to prevent a respiratory
infection?
6. Can hepatitis be treated successfully with
antibiotics? Explain.
What are microorganisms that cause
disease?
Bacteria: made of only a single cell … most are
harmless
• Helps digest food … good // cause disease …
bad
• Can produce harmful toxins that cause disease
• Interferes with cellular function or kills good
cells.
• Can be treated with antibiotics.
BACTERIA cell structure
You Tube
• What is the Difference between Bacteria and
Viruses?
• Microbiology Bacteria Structure
……………………………………………………………………………………………………………………………………………………………………………..
Bacteria comes in 3 basic shapes:
Coccus … round shaped
Bacillus … oblong shaped with a tail … most common … easily binds to other
cells
Spiral … ‘S’ -shaped
More Bacteria (most common)
What are microorganisms that cause
disease?
Virus: a piece of genetic material surrounded by
a protein (coated)
• Cannot reproduce on its own
• Must invade a living cell to survive / multiply
• Then the immune system begins to fight the
virus.
• Antibiotics do not work against viruses.
Virus Cell Structure
Virus
example
structure
What is a virus?
Ebola virus
What are microorganisms that cause
disease?
Fungi:
• Plant-like organism such as mold … yeast
• Cause disease of the: lungs – mucous
membranes – skin
• Athlete’s foot common example
FUNGI CELLS
RINGWORM
MYTH:
• ringworm is caused by a worm
--------------------------------------------------• What do you think … make a note in your
notebook
• Then compare and share with a neighbor.
FUNGI
FUNGAL INFECTION
FUNGAL INFECTION
Fungal Infections
Oral thrush
Ringworm
RINGWORM
ringworm
Fact:
• It is not caused by any worm
• A group of fungal cells
• It get’s it name from the ring-like pattern it
forms on the skin
What are microorganisms that cause
disease?
Protozoa: larger and more complex than
bacteria
• Made up of one cell
• Malaria example
Protozoa
• Larger and more
complex than bacteria
• Made up of one cell
• Malaria example
Malaria: mosquito is a vector
What are microorganisms that cause
disease?
Rickettsias: look very much like bacteria
• Enter the body through insect bites
• Typhus is an example
Complications from rickettsial diseases
• Complications are uncommon for most rickettsial diseases,
especially if diagnosed early and appropriate treatment initiated
promptly. Rickettsialpox is a self-limiting disease and has no
complications. Complications that may occur in some rickettsial
diseases include:
• Bronchopneumonia
• Congestive heart failure
• Multi-organ failure
• Deafness
• Disseminated intravascular coagulopathy (DIC)
• Myocarditis (inflammation of heart muscle)
• Endocarditis (inflammation of heart lining)
• Glomerulonephritis (inflammation of kidney)
Rickettsias
Prevention Strategies
make a list of ways to
avoid getting a communicable
disease.
In your notebook:
……………………………………………………………………………………………………………………………………………………………………………..
Compare and share your answer with a different neighbor.
Check your answers to the last 4
formative questions
How is a virus different from bacteria?
A virus is a piece of genetic material
surrounded by a protein coat.
While bacteria are single celled
microorganisms that live almost everywhere
on earth.
How is a common cold different from
the flu?
The symptoms of the flu, which
include high fever & fatigue, are
more serious than the symptoms of
the common cold.
What are 3 ways to prevent a
respiratory infection?
• Avoid close contact with sick people.
• Wash your hands often.
• Avoid touching your mouth – eyes – nose.
Can hepatitis be treated successfully
with antibiotics? Explain?
• Hepatitis cannot be treated with
antibiotics.
• Because it is caused by a virus.
PART 2
TRANSMISSION OF DISEASE
LEARNING TARGETS
• I can describe the ways in which
microorganisms are spread / transmitted
---------------------------------------------------------------Key concepts: Germs / pathogens are so small
and cannot be seen unless a microscope is used.
Disease may be spread and passed on to others
without knowing it.
Essential Question:
Why is it important to understand
how the immune system works?
-------------------------------------------------Write this question in your notebook
& answer it.
------------------------------------------------------------------------------------------------------------------------
… then … compare / share
REVIEW
• Communicable diseases start with germs.
• PATHOGEN: is the scientific name for a germ.
• A pathogen us a microscopic organism that
causes communicable diseases.
---------------------------------------------------------------Name the 5 pathogens we studied … list them in
your notebook.
Check your list:
•
•
•
•
•
Bacteria
Virus
Fungi
Protozoa
Rickettsias
Vocabulary
INFECTION: is a condition that occurs
when pathogens enter the body –
multiply – damage body cells.
……………………………………………………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………………………………………………….
If the body is not able to fight off infection,
DISEASE DEVELOPS.
Vocabulary:
TOXIN: a substance that kills cells or interferes
with cellular functions.
………………………………………………………………………….
** Like most micro-organisms that enter the
body of a healthy individual, bacteria /
pathogens are destroyed by the same immune
system.
Vocabulary:
ANTIBODY: Proteins that
act against specific bacteria
that produce disease(s).
Quick Question
In your notebook … CAN YOU … ??
List 5 ways communicable diseases
are spread.
………………………………………………………………………………………………………………………………………
Compare / share
How Diseases Are Spread: Check your
answer
• Direct contact
• Indirect contact
• Vectors
• (Impure) Water / food
• Airborne transmission
• Also, droplet contact
DIRECT CONTACT
• When you touch another:
– person
– animal
– object
• Kissing … biting … cough
… sneezing … sexual
activities … placenta to
unborn baby
<> all have saliva / mucus
• Puncture wounds (rusty
nail)
What is transmission by DROPLET
CONTACT?
• Infected droplets that come in contact with
the eyes – nose – mouth
• Can be generated by an infected person who
coughs / sneezes
• Droplets to large to stay airborne … quickly
settle out of the air
• Generated by certain medical procedures …
scopes … must wear protective equipment
Droplet transmission
Disgusting

* Measles – SARS are
examples, capable of
droplet transmission
What is transmission by INDIRECT
CONTACT?
Gets infected from a contaminated surface.
• Door knobs
• Tables – beds – chairs
• Computer keyboards– mice – electronic
device buttons
• Pens – pencils – phones
• Children’s toys
{Without being close to an infected person}
Sharing electronics / ear buds
What is AIRBORNE TRANSMISSION?
• Evaporated droplet particles
• Dust particles containing microorganisms that
can be suspended in the air for long periods of
time.
• Must be capable of surviving outside of the
body for long periods of time.
• Must be resistant to drying,
Airborne disease examples:
•
•
•
•
•
Chicken pox
Tuberculosis
Measles
Influenza
Anthrax (from soil)
………………………………………………………………………………………………………………………………………
• All do not settle quickly on surfaces
• All travel through the air over long distances
Airborne diseases
Chicken pox blisters
Measles … rash
What is VECTOR (borne) transmission?
• Animals capable of transmitting a disease
• Flies – mites – ticks – fleas – rats – other wild
or tame animals
• Most common is the mosquito
• Vectors add another dimension … they are
mobile … to increase range of disease
Tick-borne diseases
Bartonella rash
Lyme disease
more on vectors …
• Biting is NOT the only way to transmit a
disease.
• Disease may be spread through the feces of a
vector.
• Microorganisms may be located on the
outside of a vector … legs on a fly … and
spread through physical contact with food
What is fecal – oral transmission?
• Organisms that infect the digestive system
• Enter body: ingestion of contaminated food or
water
• Microorganisms multiply & shed from the
body in the feces … contaminates water
• Fish & shellfish that live in these water may be
used as a food source … or under cooked food
• Or inadequate hand washing  food handling
REVIEW for QUIZ
• When you have symptoms … runny nose –
fever … you are contagious
• Spread by direct or indirect contact
• Your body’s first line of defense …
- skin – tears – saliva – mucous membranes
- tissues that line the mouth – throat – nose - eyes
INFECTION: PATHOGENS MULTIPLY …
BODY DEVELOPS A FEVER TO MAKE IT HARD FOR
GERMS TO LIVE.
Part 3
STRATEGIES FOR PREVENTING
COMMUNICABLE DISEASES
Learning Targets
• I can examine ways the body protects itself
against invading pathogens.
• I can develop strategies for caring for the immune
system and preventing disease.
---------------------------------------------------------------Key concepts: Physical & chemical barriers
– How the immune system is active & passive
– First & second line of defenses
– Prevention strategies
PREVENTION
1. Washing hands … most effective strategy
- after handling / cleaning animals
- when someone is ill
2. Handle food properly … wash hands first
- chill food / leftovers quickly
- separate raw meat from other foods
- cook food to proper temperatures
- use paper towels … not dishcloths / sponges
Quick Question…
What are other ways the body protects itself
against invading pathogens?
Put your answer in your notebook.
---------------------------------------------------------------Compare / share
… next slide … check your answer
Vocabulary words / terms
PHYSICAL & CHEMICAL BARRIERS … examples:
- physical barriers … skin … outside the body
- mucous membrane linings … inside the body
[trap invaders … bronchial tubes]
THESE ARE THE 1ST LINE OF DEFENSE
2 Lines of Defense:
• First line of defense … review
- skin
- mucus
- sweat
- tears
• Second line of defense
- inflammatory response
- fever
Vocabulary: physical / chemical
barriers
FIRST LINE OF DEFENSE, continued
• Chemical barriers …
- enzymes in tears – saliva destroy / disable
- cilia … sweep mucus & pathogens to
cough out or swallow
- gastric juice … destroys pathogens that
enter through nose / mouth
vocabulary
IMMUNE SYSTEM:
is a network of cells – tissues – organs –
glands – chemicals that fight off pathogens
---------------------------------------------------------------Words & terms continue through the
presentation.
Immune System
Inflammatory Response: 2nd Line of
Defense
Is a reaction to tissue damage caused by infection /
injury.
Purpose: is to prevent further injury & stop
invading pathogens.
= swelling … fluid & cells leak into the area
= red … vessels expand for extra blood flow
= gastric juices … destroys pathogens that enter
through the nose & mouth
= pain … due to pressure on nerve endings
Infected sore / wound
PHAGOCYTES
Are white blood cells that attack invading
pathogens.
= pus … a collection of dead white blood cells
& damaged tissue at site … as a response to
bacteria
= tissue repair can begin to prevent reoccurring infection
ANTIGEN
Is a substance that is capable of triggering an
immune response.
= found on the surface of pathogens & in
toxins
= becomes recognized by white blood
cells
(It triggers your immune system to get to work.)
IMMUNITY
Is the state of being protected against a
particular disease.
= coded
in the white blood cells
LYMPHOCYTE
Is a specialized white blood cell that coordinates
& performs many of the functions specific to
immunity … 2 types: T cells and B cells
= helper T cells trigger the production of ‘B’
cells and killer T cells
= killer T cells attack the pathogens only in
infected cells
= ‘B’ cells produce / release antibodies
Review Lymphocytes:
1. T CELL RECOGNIZES A VIRUS
- divide making more T cells to recognize a virus
2. KILLER T CELLS ATTACK – DESTROY damaged
/ infected cells that contain the viruses
3. B CELLS MAKE ANTIBODIES…called Helper T cells
- they signal B cells to make antibodies against viruses
4. ANTIBODIES DESTROY VIRUSES … destroyed
by phagocytes
ANTIBODY
Is a protein that acts against a specific antigen
= attach to foreign antigens to mark them for
destruction
= some destroy invading pathogens
= others block viruses from entering body cells
LYMPHOCYTE
B cells
• Provide immunity against
ANTIGENS & PATHOGENS …
… in body fluids …
• ANTIBODIES are produced
to attack the pathogen.
T cells
• Provide a defense against
abnormal cells and
pathogens INSIDE LIVING
CELLS
• It can cause organ
transplant rejection.
LYMPHOCYTE
Lymphocytes are produced by LYMPH NODES
• HEAD
• NECK
• ARMPITS
• CHEST
• ABDOMEN
• GROIN
CARING FOR YOUR IMMUNE SYSTEM
•
•
•
•
Eat nutrient rich foods
Drink at least 8 glasses of water daily
Get plenty of rest … ave. 9 + hours of sleep
Get at least 1 hour of physical activity daily …
helps relieve stress
• Avoid sharing personal items … toothbrushes
• Avoid tobacco – alcohol – drugs
• Avoid sexual contact … some STDs (HIV) destroy
immunity
VACCINE
Dead or weakened pathogens that are
introduced into the body to stimulate an
IMMUNE RESPONSE
• Artificially acquired ACTIVE IMMUNITY
• Causes body to produce antibodies … without
getting the disease
• Some last a lifetime: polio
• Others need to be repeated: flu
2 Kinds of Immunity
Passive immunity
• Injections of antibodies
from another person /
animal who is immune to
the disease … short lived …
examples:
• Chicken pox
• Tetanus
Natural passive immunity
• Antibodies pass from
mother to child … while
pregnant or nursing
CAN YOU ANSWER THESE ???
1. Name a physical barrier that work against
pathogens.
2. WHAT IS A REACTION TO TISSUE DAMAGE
CAUSED BY INJURY OR INFECTION?
•
•
•
•
Immune response
Specific defenses
Immune system
Inflammatory response
CAN YOU ANSWER THESE ???
3. IN THE IMMUNE RESPONSE …
* lymphocytes invade the body
* helper T cells divide to produce plasma
* pathogens engulf macrophages
* antibodies bind to antigens
CAN YOU ANSWER THESE ???
4. PART OF THE IMMUNE SYSTEM’S JOB IS TO
“REMEMBER”…
a. the lymph sent through the lymphatic sys.
b. the B cells produced by antibodies
c. the coordinated actions of T cells
d. the antigens it has dealt with in the past
CAN YOU ANSWER ???
5. WHICH IS AN EXAMPLE OF ACTIVE
IMMUNITY?
a. immunity produced in a baby by a nursing
mother
b. immunity produced by a vaccine.
c. immunity produced in a baby during
pregnancy
d. Immunity produced by injection of animal
antibodies
LET’S DOUBLE CHECK:
• WHAT IS A LYMPHOCYTE?
ANSWER:
A LYMPHOCYTE IS A SPECIALIZED
WHITE BLOOD CELL THAT
COORDINATES MANY OF THE
FUNCTIONS OF SPECIFIC
IMMUNITY.
???
• WHAT IS A PHAGOCYTE?
ANSWER:
• A PHAGOCYTE is a white blood
cells that surrounds and destroys
a pathogen.
OK … last ???
• WHICH PROTEIN ACTS AGAINST A
SPECIFIC ANTIGEN?
ANSWER:
• A protein that acts against a specific
antigen is a ANTIBODY.
PART 4
Emerging Diseases & Pandemics
What are emerging infections?
• Some communicable diseases that are
increasing
• They may rise in the near future
• Examples that will spread to humans:
– Avian influenza … virus lives in the intestines
– Spread through chickens – ducks – turkeys
– H1N1 virus … combination of human, pig, bird flu
viruses … now being spread from human to human
Other emerging infections:
Salmonella & E. coli
• Bacteria that can live in the
intestines of animals
• Food must be well cooked
• Food must be stored at
proper temperatures
Recreational water illness
• E. coli or giardia
• Infect digestive system
• Spread by swallowing or
having contact with
untreated water
• Or water contaminated with
sewage from humans or
animals
• On the rise throughout the
world
Other emerging infections:
•
•
•
•
HIV/AIDS
LYME DISEASE
WEST NILE VIRUS
SEVERE ACUTE RESPIRATORY SYMDROME
(SARS)
• MAD COW DISEASE
How diseases affect the world:
• PANDEMIC
- diseases can spread faster due to trade and
travel
- global outbreak of an infectious disease