Download Infectious Diseases

Infectious Diseases
Viruses
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Virus- a tiny, disease-causing particle that invades a healthy cell
and instructs that cell to make more viruses.
Viruses are a non-living thing.
Some viruses can be spread through direct person-to-person
contact. Ex. Shaking hands or kissing.
Other viruses are spread through indirect contact. Ex. Sneezing or
sharing a drink.
Vaccine- Medicine that contains killed or weakened pathogens and
is given to protect your against a particular disease. Vaccines
stimulate your immune system to produce antibodies.
Antibody- Chemical that your body produces to fight invading
pathogens.
www.brainpop.com viruses
Bacteria
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Bacteria are living things and are more complex than viruses.
Bacteria- extremely small, single-celled organisms that do not
have a nucleus.
Most bacteria can live on their own and they live everywhere.
Bacteria can be spread through direct or indirect contact.
Most bacteria is harmless to humans, some bacteria can also
be helpful.
Examples of disease caused by bacteria include whooping
cough, anthrax, tooth decay, and some forms of food
poisoning and ulcers.
www.brainpop.com Bacteria
Controlling Bacteria
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Washing your hands.
Keeping your kitchen clean.
Most bacterial diseases can be treated with
antibiotics.
Antibiotic- a medicine used to stop the growth of
or to kill bacteria and other microorganisms.
*Antibiotics are not used for any noninfectious
disease.
Protozoa and Parasites
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Protozoa- small, single-celled organisms
that have a nucleus. They are more
complex than bacteria.
Parasite- organism that gets its food from
another organism, called the host, without
killing the host. Example: Mosquitoes,
Leeches.
Protozoa and Parasites
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Most protozoa are harmless to humans but few can cause
illness.
Giardia is protozoa that can be found in contaminated water
supplies. Giardia can cause stomach upset, cramps, and
diarrhea in humans. They are relatively rare in the United
States.
Plasmodium- is a parasite that causes malaria in humans.
Plasmodium is carried by certain kinds of mosquitoes.
Malaria is usually found in tropical countries and is rare in the
United States.
Antibiotics and other drugs are used to treat most diseases
caused by protozoa and other parasites.
Fungi
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Fungi- complex organisms that cannot make their own food.
Fungi break down other substances and absorb the nutrients
from them.
There are over 100,000 species of fungi.
Most fungi is harmless to humans and some fungi such as
yeast and edible mushrooms are useful.
The most common fungal diseases are athletes foot and
yeast infections.
Fungal infections can be spread by person-to-person contact.
Others can be spread by fungal spores in the air, water, or
soil.
Most fungal medicines can be treated with medicines applied
to the skin, others can be treated by oral medications.