Download Infectious Diseases

Infectious Diseases
Diseases caused by a virus, bacterium, protist
or fungus and are spread from an infected
organism or the environment to another
organism
Biological Vector: disease carrying organism
(rats, birds, dogs, cats, mosquitoes, fleas, flies)
People can be carriers too!
Louis Pasteur
• French Chemist
• Realized that microorganisms could
cause diseases in humans.
• Pasteurization: the process of
heating a liquid to a specific
temperature to kills most bacteria.
• Virus: a minute piece of genetic
material surrounded by a protein
coating that infects and multiplies in
host cells
• The connection between viruses
and disease transmission was not
understood until the late 1800’s and
early 1900’s
Surgery Through History
• Past: bloody aprons, dirty tools
and street clothes were
commonplace
• Present: disinfectants,
sterilized tools, antiseptics and
protective (sterile) clothing.
• Joseph Lister: one of the first
surgeons to promote keeping
things clean during surgery.
CDC
• Centers for Disease Control and Prevention
– An arm of the US Department of Health
– Monitor the spread of diseases in the US and
worldwide.
– Located in Decatur, GA (east of Atlanta near Emory
University)
– Study known pathogens for improved treatments
– Working to be prepared for emerging health threats
– Provide health and safety information to the public
– www.cdc.gov
Sexually Transmitted Diseases
STD’s
• Infectious diseases that are passed from
person to person through sexual contact
• Bacterial STD’s - treated with antibiotics
– Gonorrhea
– Chlamydia
– Syphilis
• Viral STD’s – treated with antiviral drugs
– Genital Herpes
– HIV
Bacterial STD’s
•
Gonorrhea and Chlamydia
– May be present for some time before symptoms
appear.
– Symptoms: painful urination, genital discharge and
genital sores.
– Usually respond to antibiotics
– Left untreated, they can leave patients sterile or with
permanent damage to reproductive organs
•
Syphilis: caused be a spiral shaped bacterium
– Has 3 stages:
1. Sores on mouth or genitals (10 to 14 days)
2. Involve rash, fever and swollen lymph glands (up to a year)
3. Affects cardiovascular and nervous systems
Viral STD’s
• Genital Herpes
– Lifelong viral STD
– Causes painful blisters on sex organs
– Can be transmitted through sexual contact or
from mother to child in childbirth
– Goes dormant and then flairs up suddenly
– No cure and no vaccine, but can be treated
with antiviral medicines
• Human Immunodeficiency Virus (HIV)
HIV
• Exists in blood and other body fluids
• Can hide in the body’s cell for years
• Transmitted by having unprotected sex, and
reusing infected hypodermic needles
• Early on was transmitted through blood
transfusions but now the blood supply is
screened to prevent this.
• Can be transmitted from mother to child through
the placenta.
• The virus cannot multiply outside the body
• Cannot be transmitted through casual contact
such as touching an infected person or objects
that they have touched.
Acquired Immune Deficiency
Syndrome (AIDS)
• Attacks the body’s immune system
– Enters the T-cells and multiplies
– Infected Helper T cells burst and infect more T-cells
– When T-cells are destroyed, not enough B-cells are
activated to produce antibodies
– The body can no longer fight invading antigens and is
unable to fight HIV and other pathogens
– Most AIDS patients die from other diseases such as
TB, pneumonia or cancer.
– The is no known cure but we have developed a series
of medicines that interfere with the way the virus
multiplies in the host cell (called AZT)
Fighting Disease
• Washing wounds with soap and water is the first
step to disease prevention
• Cleaning with and antiseptic and covering with a
sterile bandage are other steps
• Washing hands (and entire the body) can help
prevent the spread of disease
• Regular flossing and brushing teeth can also
prevent the spread of disease
• Healthy habits (nutrition, sleep, exercise) can
make the body less susceptible to disease