prevention and treatment infectious diseases. misconceptions – these statements are false!...
TRANSCRIPT
PREVENTIONAND
TREATMENT
Infectious Diseases
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 DiseasesBacteria, Viruses, Fungi, and Protists that
cause Infectious DiseasesTransmission of DiseasesPrevention of DiseasesTreatment 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 treatWhy do you think this is?
Examples
How do Viruses compare to Bacteria size wise?
Virus Disease
orthomyxoviruses Influenza (flu)
rhinoviruses Common Cold
retroviruses (HIV) AIDS
flaviviruses West Nile
Paramyxoviruses Measles, mumps
varicella-zoster Chicken Pox
rhabdoviruses rabies
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 asmycoses
Most are simply bothersomeSome 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. Air2. Food3. Water4. 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
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 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 (often fluid and rest)
Reduce ability of the virus to reproduce
Fungi Fungicide Destroys or inhibits growth of fungus
Protists Deworming agents
(Specific to individual pathogen)
Paralyze or kill parasite
References
http://emedicine.medscape.com/infectious_diseases
http://www.microbiologyprocedure.com/infection-and-diseases/diseases-caused-by-bacteria.htm
http://www.ehow.com/about_5139239_diseases-do-protists-cause.html
http://science.education.nih.gov/supplements/nih1/diseases/guide/understanding1.htm
http://www.fungi4schools.org/Documentation/03World-of-Fungi/WF05_Fungi_and_Disease.pdf
http://www.phac-aspc.gc.ca/media/nr-rp/2005/2005_3bk1-eng.php