http://www.youtube.com/watch?v=zTWZtElv
MAU&feature=related (revolting facts)
vector borne
direct contact
antibiotic
vaccines
epidemic
carrier
indirect contact
fomite
antiviral
outbreak
pandemic
borne
1. What is the difference between indirect contact, direct
contact, and vector borne? Describe examples of each.
2. What is the difference between an outbreak, epidemic, and
pandemic? Describe an example of each.
3. What are the main differences between antibiotics and
vaccines?
4. What are the similarities between antibiotics and vaccines?
5. What is the relationship between cold weather and becoming
sick?
GUIDING QUESTIONS
TERMS
Pathogen - a micorbe that
causes disease
Transmission of a disease
– the path a pathogen
takes to get from host to
host
Host – the infected
organism
Carrier – an organism that
harbors a pathogen and
can transmit the
pathogen to others but
shows no symptoms
•
•
•
•
Direct contact
Indirect contact
Food/air-borne
Vector borne
4 MAIN TRANSMISSION
PATHS FOR PATHOGENS
•
•
•
•
Direct contact
Indirect contact
Food/air-borne
Vector borne
For each you need to know:
1.The definition
2.How the transmission occurs
3.Examples
DISEASE TRANSMISSION PATHWAYS: DIRECT CONTACT
Direct contact - transmission
requires physical contact
with an infected person
Direct contact through:
kissing, sexual contact,
oral secretions (saliva),
blood, or contact with body
lesions(sores or open
wounds).
Examples of pathogens
spread though direct
contact: Cold, flu, HIV,
Staphylococcus bacteria,
Hepatitis A
•
•
•
•
Direct contact
Indirect contact
Food/air-borne
Vector borne
DISEASE TRANSMISSION PATHWAYS: INDIRECT CONTACT
Indirect contact – a person is
infected from contact with a
contaminated surface (called a
fomite). Some microbes can
survive on surfaces for a long
period of time
Indirect contact includes: touching
contaminated surfaces then
putting contaminated hands or
fingers in mouth, eyes, nose, etc.
Examples: flu, Hepatitis B, HIV (via
contaminated needles)
Fomites
Watch the video: http://www.youtube.com/watch?v=yToii3-p-NI
•
•
•
•
Direct contact
Indirect contact
Food/air-borne
Vector borne
DISEASE TRANSMISSION PATHWAYS: FOOD BORNE PATHOGENS
Food Borne- transmission through
eating or drinking water or food
that is contaminated with feces
(poop) or eating contaminated
meat that is undercooked meat
Process – Pathogens enter the
body through ingestion and
inside the digestive system
(usually within the intestines)
these microorganisms multiply
and are then shed from the body
in feces.
•
•
•
•
Direct contact
Indirect contact
Food/air-borne
Vector borne
DISEASE TRANSMISSION PATHWAYS: AIR BORNE
Air Borne- residue from evaporated
droplets or dust particles
containing microorganisms
remain suspended in air for long
periods of time, capable of
surviving for long periods of time
outside the body and must be
resistant to drying.
transmission occurs when these
droplets enter the upper and
lower respiratory tracts of a
person
Examples: Tuberculosis ,
Chickenpox, Measles, Valley
Fever
•
•
•
•
Direct contact
Indirect contact
Food/air-borne
Vector borne
DISEASE TRANSMISSION PATHWAYS: VECTOR BORNE
Vector Borne - vectors are animals that
are capable of transmitting
diseases, transmission requires
physical contact with a vector. Or
the vector‘s feces
Vector Borne includes: Examples of
vectors are flies, mites, fleas, ticks,
rats, dogs, and mosquitoes (the
most common vector ). Mosquitoes
transfer disease through the saliva
which comes in contact with their
hosts when they are withdrawing
blood.
Examples: malaria, rabies, Lyme
disease, West Nile Virus, Giardia,
bubonic plague
•
•
•
•
Direct contact
Indirect contact
Food/air-borne
Vector borne
REDUCING
DISEASE
TRANSMISSION
http://www.who.int/csr/don/en/
http://www.cdc.gov/outbreaks/
http://www.youtube.com/watch?v=d5qovHD_kjQ
VACCINES - STIMULATE THE PRODUCTION OF
ANTIBODIES AND PROVIDE IMMUNITY TO PATHOGENS
• Vaccines are made of the actual pathogen – the bacteria or
virus
• When the vaccine is injected, your immune system goes to
work to make B-cells, antibodies, and memory cells.
• The memory cells will remember the pathogen so if you are
exposed to the full blown microbe your immune system will be
ready
VACCINES
Produced using bacteria or Examples for virual
viruses that are……..
pathogens
Examples for bacterial
pathogens
weakened (attenuated): can measles, mumps,
only reproduce <20 times.
chickenpox
Typhoid
Inactivated: cannot
reproduce
polio, hepatitis A, influenza,
rabies
plague, cholera
Broken up into proteins
taken from the surface of
the virus OR toxins
produced by the bacteria.
hepatitis B, HPV
ANTIBIOTICS – CHEMICALS MADE TO KILL BACTERA
90% of antibiotics are
made from bacteria or
fungi
Antibiotics destroy the
bacteria or prevent
bacteria from
reproducing
Produced by a process
of fermentation - the
source microorganism
is grown in large
containers (100,000–
150,000 liters or more)
containing a
liquid growth medium.
ANTIBIOTIC RESISTANCE
“Each year in the United States, at least 2 million
people become infected with bacteria that are
resistant to antibiotics and at least 23,000 people
die each year as a direct result of these infections.”
(Threat 2013)
http://www.youtube.com/watch?v=zjR6L38yReE
ANTIVIRALS
Made primarily from inactivated viruses
Antivirals do not destroy the viruses - they inhibit the
reproduction by blocking the ‘keys’ on the virus
VIRAL MUTATIONS
When a cell makes copies of a virus, they are making copies of the
DNA or RNA.
So many copies are made and not all copies will be exactly alike.
Some may have mutations that make the virus harder to make a
vaccine for, to be recognized by the memory cells, harder to
neutralize, or the mutations may make the virus weaker.
https://www.washingtonpost.com/posttv/national/health-science/how-a-virusmutates/2015/02/23/4811cf5a-bba3-11e4-9dfb-03366e719af8_video.html
ANTIFUNGAL
Destroys the cell
wall of the
fungal cells
Prevents the
fungus from
growing and
reproducing
Examples:
Aspergillosis,
ringworm,
athlete's foot
https://www.youtube.com/watch?v=RWiOhlq
EDz4 (cold facts)
• Ro is the basic
reproduction
number for
infectious diseases
• Ro is the number of
people one
infected person
infects
• For example: an Ro
value of 3 means
that each infected
person will infect 3
other people
BASIC REPRODUCTION NUMBER FOR INFECTIOUS
DISEASES, RO