Download Infectious Diseases - Biology-Resource-Package-11C

Infectious Diseases
PREVENTION
AND
TREATMENT
Misconceptions – These statements are False!
 Antibiotics can cure all types of infectious diseases
 Antibiotics can be taken to prevent infections
 Colds and Flu are caused by bacteria (or general confusion
over which illnesses are caused by viruses vs. bacteria)
 You can get the flu from the flu shot
 Viruses are living organisms
Overview
 Infectious Diseases
 Bacteria, Viruses, Fungi, and Protists that cause
Infectious Diseases
 Transmission of Diseases
 Prevention of Diseases
 Treatment of Diseases
Infectious disease
 Defined as:
- A disease caused by a microscopic pathogen such as
bacteria, viruses, fungi, and parasites
- These diseases can be transmitted from person to
person
Bacteria and Disease
 Bacteria cause disease when they build up in large
numbers in an affected area of the body.
 The toxins from the bacteria “overload” a person’s
immune system and it’s ability to remove these
poisons
 This can have varying effects on the host (depending
on bacteria/disease)


decrease function of cells and tissues
destroying cells and tissues
Examples
Bacteria
Disease
Clostridium
Botulism, tetanus, gangrene
Streptococcus
Strep throat, scarlet fever, pneumonia
Staphylococcus
Boils, food poisoning, skin infections,
pneumonia
Neisseria meningitidis
Meningococcal Meningitis
Vibrio cholerae
Cholera
Adapted from Nelson Biology 11 College Preparation
Viruses and Disease
 Viruses depend on host cells to survive and
reproduce
 Through the process of reproduction, viruses attack
host cells

This is what causes the symptoms of the disease
 Viral Infections are often difficult to treat
Why do you think this is?
Examples
Virus
Disease
orthomyxoviruses
Influenza (flu)
rhinoviruses
Common Cold
retroviruses (HIV)
AIDS
flaviviruses
West Nile
Paramyxoviruses
Measles, mumps
varicella-zoster
Chicken Pox
rhabdoviruses
rabies
 How do Viruses compare to Bacteria size wise?
Protists and Disease
 Protists which are single celled eukaryotes (examples
include amoeba, paramecium)
 Protists can be parasitic, causing harm to the host
organism

What is meant by parasitic?
Examples
Protist
Disease
Plasmodium
Malaria
Trypanosoma
African Sleeping Sickness
Giardia lamblia
Giardiasis
Fungi and Disease
 Fungi are responsible for many human diseases.
 These diseases are referred to as
mycoses
 Most are simply bothersome
 Some can be life threatening
Examples
Fungus
Disease
Microsporum
Ringworm
Epidermophyton floccosum
Athlete’s foot
Blastomyces dermatidis
Blastomycosis
• Amanita phalloides (a.k.a Dead cap) world’s most
dangerous mushroom. Eating one or two can be fatal
Disease Transmission
 Infectious diseases can spread easily from person to
person in five different ways
 1._______________________________
 2._______________________________
 3._______________________________
 4._______________________________
 5._______________________________
Disease Transmission
 Infectious diseases can spread easily from person to
person in five different ways
 1. Air
 2. Food
 3. Water
 4. Person to Person contact (direct or indirect)
 5. Animal bites
Examples of Transmission Methods
Disease
Pathogen
Transmission Method
AIDS
HIV
Person to Person (e.g.
sexual intercourse)
Common Cold
rhinovirus
Air, person to person
Malaria
Plasmodium (protist)
Mosquito bites
Measles
paramyxovirus
Air, person to person
Botulism
Clostridium botulinum
(bacteria)
Food
Adapted from Modern Biology (2002)
Prevention
 Vaccinations
 Immune System
 Specific
 Non-Specific – Body’s “first line of defense” for preventing
pathogens from entering the body
Non-Specific Immunity





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Skin – keratin shield acts as a barrier
Sweat, oils, and waxes released by skin – toxic to many bacteria
and fungi
Mucus membranes – Barrier secretes mucus which traps
pathogens
Stomach Acid – destroys most swallowed pathogens
Inflammatory Response – Injured cells send a chemical signal
as pathogens enter (through a cut for example). Chemical signal
attracts phagocytes to destroy foreign pathogen
Fever – Body’s response to infection
Specific Immunity – The Immune System
 Include several organs within the body working
together to identify pathogens and kill them

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Bone marrow
Thymus
Lymph Nodes
Tonsils
Adenoids
Spleen
A great animated video to describe the immune system
Vaccinations
 Vaccines contain pathogens or toxins that have been
modified so they can no longer cause disease
 They contain antigens that stimulate an immune
response  this produces memory cells
 Some diseases that have been controlled through
vaccines:

Polio, Measles, Mumps, Tetanus, Diphtheria,
Treatment
 Different depending on the pathogen causing the
disease
Pathogen causing
Disease
Treatment
How it works
Bacteria
Antibiotics
Kill or inhibit
growth of Bacteria.
Virus
Some Antivirals
Reduce ability of the
(often fluid and rest) virus to reproduce
Fungi
Fungicide
Protists
Deworming agents
Destroys or inhibits
growth of fungus
(Specific to
Paralyze or kill
individual pathogen) parasite
References
 http://emedicine.medscape.com/infectious_diseases
 http://www.microbiologyprocedure.com/infection-and
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
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diseases/diseases-caused-by-bacteria.htm
http://www.ehow.com/about_5139239_diseases-doprotists-cause.html
http://science.education.nih.gov/supplements/nih1/disea
ses/guide/understanding1.htm
http://www.fungi4schools.org/Documentation/03Worldof-Fungi/WF05_Fungi_and_Disease.pdf
http://www.phac-aspc.gc.ca/media/nrrp/2005/2005_3bk1-eng.php