Download Infectious Diseases PPT

We are surrounded by millions of…
MICROBES
Tiny organisms,
such as bacteria and viruses,
that are too small to be seen with
the naked eye.
Microbes AKA
MICROORGANISMS
oFound on all surfaces of
things you touch
oIn the air you breathe
oAll surfaces of your body
MICROBES
Microbes can be
POSITIVE:
o Decompose waste
o Make nutrients
Most microbes
are harmless!
Others…
develop
infectious
diseases
WHAT IS AN INFECTIOUS DISEASE?
Diseases caused and
transmitted from person to
person by microorganisms or
their toxins
Also referred to as:
o Communicable/Contagious diseases
o Infections
PATHOGENS
Microbes that cause disease
1. Bacteria
2. Virus
Microscopic single
celled organism
capable of causing
disease.
Organisms that contain
only genetic material
and protein coats,
and that are totally
dependent
on the cells they infect.
BACTERIA
o Bacteria thrives in warm, dark, moist
environments
o Example: Deep puncture wounds
o A weakened immune system
will result in illness if bacteria is present
Beneficial Bacteria!
o Digestive tract
Tetanus Shot
BACTERIA VS. VIRUSES:
WHAT’S THE DIFFERENCE
Bacteria
Independent single cell
organisms
Viruses
Completely dependent
on cells within the
human host
GENETIC MATERIAL
VIRUSES
Using the human host cells,
viruses tap into the genetic code
of the cells, and use the cell to
reproduce more of the virus
New viruses will continue to
circulate throughout the
human host and infect other
healthy cells
Parasitic
Relationship
VIRUSES
o It is typical for people to suffer through one cold, or
upper respiratory tract infection in a year – once
symptoms subside, the virus is usually gone from the
body
o Some viruses can remain in the body long after
symptoms diminish – these viruses are still
communicable
DORMANCY
OTHER HARMFUL PATHOGENS
1) Fungi – living things that absorb and use
nutrients of organisms they invade
2) Protozoa – tiny, animal like cells, some of which
can cause illness
3) Worms – visible parasites that burrow into the
blood supplies of victims
4) Parasites – living things that depend on the
bodies of others that they inhabit
HOW CAN WE DEFEND AGAINST
INFECTIOUS DISEASES
Our immune system is our bodies natural defense against
illness and disease…as we age our immune system
adapts
HOW ARE DISEASES SPREAD?
Example:
o Someone who has a cold may sneeze into the air,
bacteria will circulate and land on various surfaces
o Another person breathes in the bacteria, touches an
object that was infected and catches the cold
o The cycle repeats – continually spreading and
contracting of illness
1)
HOW ARE PATHOGENS
CONTROLLED?
Disinfectants –
chemicals that kill
pathogens on surfaces
2) Washing hands with
soap and warm water,
regularly
3) Treating open
wounds with antiseptic
ointment and properly
covering the wound
4) Public sanitation –
water treatment plants
CONTROLLING INFECTIOUS
DISEASES
Vaccines : drugs made from alter microbes or their poisons injected or given by mouth to produce immunity
Public health organizations control diseases
but cannot eliminate them!
THE BODY’S DEFENSE
Natural barrier against infectious diseases:
Skin,
Membranes
Immune system
can block most infectious diseases
IMMUNE SYSTEM
Bone marrow produces lymphocytes (white blood cells) –
imperative in immunity!
Thymus gland
transforms lymphocytes
-> T cells
Other lymphocytes
become B cells =
antibodies
Protein molecules that
fight infectious invaders
IMMUNE SYSTEM
Antigens
Foreign substances in the body
(bacteria/viruses) that stimulate the
immune system and produce antibodies.
IMMUNE SYSTEM
During periods of infection:
o Lymphocytes draw
back into the lymph
nodes – causes
swelling
o Travel through body
fluids when adequately
prepared to fight
o Histamine inflammation of tissue
o Inflames site of
attack and draws
defenders to aid in
that location
o Antihistamines are
taken to reverse the
effects and relieve
unwanted symptoms
IMMUNE SYSTEM
T and B cells work as a unit
T cells detect an
enemy and send
out chemical
messages
B cells respond to
the message by
making antibodies
that destroy the
pathogen
Remaining lymphocytes “remember” the
invader so that in the future, the illness will
not occur or be nearly as detrimental
COURSE OF AN ILLNESS
Bacterial Infection:
o Antibiotics can be utilized
o Specific antibiotics must be
used for specific pathogens
Viruses are not cells!
Viral Infections:
o Antibiotics CANNOT be utilized
o Why? – antibiotics prevent
cell growth
o Viruses must run its course –
basic medicines can be used to
relieve symptoms
COURSE OF AN ILLNESS
o Body’s natural reaction to
infection = FEVER
o Assist the body in fighting an
infection by increasing
temperature and making the
environment unsuitable for the
infection to thrive in
o Activates the immune system
TAKING ACTION
o
o
o
o
o
Keep immunizations current
Eat a healthy diet
Reduce or eliminate alcohol intake
Reduce and manage stress
Get regular exercise
AIRBORNE INFECTION
o
o
o
o
Cover your face when you sneeze and cough
Avoid touching contaminated surfaces
Bathe regularly
Always wash your hands with soap and water –
especially when handling food
FOOD SAFETY
Bacteria in foods can
cause infection/poison in
the digestive tract –
prepare food correctly