Download File - Mrs. R`s Health for PATH

Infectious Diseases
Infectious Disease
• Aka Communicable
Diseases
• Caused by microorganisms
• Parasite – lives in/on
and feeds on host
Pathogens
• Pathogens or germ
– Micro-organisms
– Enter the body
– Multiply
– Cause disease
Bacteria
Virus
Fungi
Tiny Animals
Bacteria
• Single-cell microorganisms
• Release toxins
• Ex.
– Food poisoning –bacteria in
food
– Tetanus – bacteria on
objects/soil
Staph
Bacteria
Virus
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•
•
•
Smallest parasite
Enter cells and take over
Multiply
Cause colds/ flu
HIV
Fungi
• Not all are harmful
– Mushroom/ yeast/ mold/ fungi
• Some cause rashes
– Ringworm & athlete’s foot
Spreading Infectious Disease
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Physical contact w/ infected person
Contact w/ contaminated object
Environmental sources
Contact w/ contaminated animals
Tiny Animals
• Tape worm parasite
• Round worms
Methods of Transmission
• Droplet Contact
• Also known as the respiratory route, it is
a typical mode of transmission among
many infectious agents. If an infected
person coughs or sneezes on another
person, the microorganisms, suspended
in warm, moist droplets, may enter the
body through the nose, mouth or eye
surfaces. Diseases that are commonly
spread by coughing or sneezing include
(at least):
Droplet Transmission (cont.)
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•
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Bacterial Meningitis
Chickenpox
Common cold
Influenza
Mumps
Strep throat
Tuberculosis
Measles
Rubella
Whooping cough
Fecal – Oral Transmission
• Direct contact is rare in this route, for humans at least.
More common are the indirect routes; foodstuffs or water
become contaminated (by people not washing their
hands before preparing food, or untreated sewage being
released into a drinking water supply) and the people
who eat and drink them become infected. In developing
countries most sewage is discharged into the
environment or on cropland as of 2006; even in
developed countries there are periodic system failures
resulting in a sanitary sewer overflow. This is the typical
mode of transmission for the infectious agents of (at
least):
• Cholera
• Hepatitis A
• Polio
• Rotavirus
• Salmonella
Sexual Transmission
• This refers to any disease that can be caught during sexual
activity with another person, Transmission is either directly
between surfaces in contact during intercourse or from
secretions which carry infectious agents that get into the
partner's blood stream
• Some diseases transmissible by the sexual route include (at
least):
• HIV/AIDS
• Chlamydia
• Genital warts
• Gonorrhea
• Hepatitis B
• Syphilis
• Herpes
Transmission by Direct Contact
• Diseases that can be transmitted by direct contact are
called contagious . These diseases can also be
transmitted by sharing a towel (where the towel is rubbed
vigorously on both bodies) or items of clothing in close
contact with the body (socks, for example) if they are not
washed thoroughly between uses. For this reason,
contagious diseases often break out in schools, where
towels are shared and personal items of clothing
accidentally swapped in the changing rooms.
• Some diseases that are transmissible by direct contact
include:
• Athlete's foot
• Impetigo
• Syphilis (on rare occasions, if an uninfected person
touches a chancre)
• Warts
Vector Borne Transmission
• A vector is an organism that
does not cause disease itself
but that transmits infection by
conveying pathogens from one
host to another.
• Examples include mosquitoes,
deer ticks, animal bites, etc.
rickettsialpox
• A bacteria, rickettsia, infects a mite, the
mite then infects a human
Test Your
Knowledge!
• Is It Contagious?
Contaminated Animals
• Animal bites
• *Eating bad food*
• Rabies/ Malaria/
Bird flu
• HIV/ AIDS
Contaminated Object
• Most infections die quickly when exposed
to air
• Some can live on objects
• Lice
Contact w/ Contaminated Person
• Skin to skin contact
• Sneeze/ cough
• Cold/ STI/ flu/ chicken pox
Environmental Sources
• Food/ water/ soil
• Lead poisoning/ food
poisoning
• Fungi/ mold/ pathogens
in water
• Old food left out
• Contaminated animals
Stages of Disease
1.
2.
3.
4.
5.
6.
7.
Exposure
Incubation Period
Prodromal Period
Acute Stage
Recovery Stage
Convalescence
Immunity
Exposure & Incubation
• Exposure = contact
•Incubation = growth/ maturation
•No signs/ symptoms
•Pathogen/ parasite grows and multiplies
Prodromal Stage
• Slight signs & symptoms
• Ex: achy/ sore/ tired
• Contagious!
Acute Stage
• Severe symptoms
• Most contagious
• Most affected
Recovery Stage
• Signs/ symptoms begin to decrease
• Temperature is reduced
• Feeling better
Covalescence
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Infection is gone
Still not quite 100%
Can relapse
Need rest, sleep,
healthy diet, antibiotics
Immunity
• Feel 100%
• Body has antibodies
• Cannot catch same infection
Questions?