Transcript - Catalyst

HSERV100
Wednesday May 9, 2012
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Infectious disease:
 Describe components of the “chain of infection”
 Describe basic categories of infectious organisms
 Identify personal ways to reduce risk of infectious
disease
 Describe three components of antibiotic
resistance
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Warning- next photo gross!
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Thought process??
 What is the organism?
 Is it causing symptoms?
 Is this peak of disease or will he get worse?
 How do we treat?
 Public health:
 Will it spread to the other horses?
 Who else needs treatment?
 Can we prevent other horses from getting?
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What is an Infection?
 A disease or condition caused by a
micro-organism
 Micro-organisms are the tiniest living
organisms on earth that eat, reproduce,
and die.
 An infection is considered an illness or
disease if it interferes with your usual
lifestyle or shortens your life.
See Stages of Infection, Figure 14.1
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Incubation, Prodomal, Invasive, Acme, Decline, Covalescent, Sequelae
Pneumonic: In Portland, Infections And Diseases Can Sicken
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Koch’s postulates
Organisms must be present in every case
of disease
Organism must be isolated and grown
Test animals must develop the disease
when injected with isolate
Organism must be isolated from newly
infected animals
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Types of
Pathogens
Know the 7 types
of pathogens.
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The Chain of Infection
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The Body’s Defenses
External Barriers
 Skin (the body’s first line of defense)
 Nasal passages and ear canals protected by hair
 Lungs protected cough reflex and cilia
 Saliva contains special proteins that break down bacteria
 Stomach acids make it difficult for most organisms to survive
 Small intestines contain bile and enzymes that break down
pathogens
 Vagina is slightly acidic, discourages the growth of abnormal
bacteria
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Physical and Chemical
Barriers to Infection
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Normal Flora
Refers to the bacterial that live on or in the
body - usually with no harmful effects
On skin: staph aureus, staph epidermis,
streptococci, diptheroids, candida
Stomach/small intestine/genital:
lactobacillus
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The Body’s Defenses
Immune system: complex set of cells,
chemicals, and processes that
protects the body against pathogens
when they succeed in entering the
body
 Innate immune system (rapid response)
 Acquired immune system (recognizes
specific targets)
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Immune System
Innate system
Acquired system
acute inflammatory response
Phagocytes
B cells
T cells
Natural killer cells
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Innate Immune Response
Acute Inflammatory Response
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Acquired immune response
 Lymphocytes (white blood cells) develop a memory of
antigens
 When see again – they rapidly turn on and produce
antibodies
 Antibodies circulate in blood and bind to specific antigens
triggering immune reaction to destroy and remove
(We’ll talk more about antigens and antibodies next lecture)
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Acquired immune response
 Can develop in response to natural infection
 Can develop from immunization
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Top 10 Global infectious diseases
in mortality
Condition
Deaths
Pneumonia
4.4 million
Diarrhea
3.1 million
Tuberculosis
3.1 million
Malaria
2.1 million
AIDS
1.5 million
Hepatitis B
1.1 million
Measles
1 million
Neonatal tetanus
0.46 million
Pertussis
0.35 million
Worms
0.135 million
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New diseases arise:
 HIV
 SARS
 MDR-TB
 H1N1 influenza
 Resistant bacteria
Adults and Children Estimated to be
Living with HIV in 2008
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HIV
 RNA retrovirus
 Target CD4-T lymphocytes
 Disables the immune system
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Antibiotic Resistance
Antibiotic: drug that works by killing or
preventing the growth of bacteria
Antibiotic resistance: lessened
sensitivity to the effects of an antibiotic
 Two factors are believed to account for
resistance
 Frequency with which resistant genes arise
naturally among bacteria through mutation
 Extent of antibiotic use
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MDR-TB
 Tuberculosis – spread by aerosol
 Increase in incidence since 1985 –
people with HIV more susceptible
 Strains that are resistant to standard
antibiotics
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Methicillin resistant Staph
aureus
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Influenza
 RNA virus
 Different strains: influenza A and B cause disease in
humans
 Influenza A subtypes: H and N
 Genetic Drift: Frequent minor genetic changes
 Genetic Shift: Infrequent abrupt major genetic changes
 Influenza subtypes can infect birds, pigs, horses, dogs
and other animals
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Influenza virus
Pandemics
1918:
H1N1
1947:
H1N1
1957:
H2N2
1968:
H3N2
1978:
H1N1
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Infectious Diseases on
Campus
Illnesses on campus can be impediments to
academic performance.
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Pertussis (whooping cough)
Mumps
Staphylococcus aureus skin infections
Urinary tract infections
Common cold
Flu
Strep throat
Acute sinus infection
Mononucleosis
Bronchitis
Meningitis
Cellulitis MRSA
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Preventing illness:
 Wash your hands
 Stay in good health- eat well, sleep regularly,
manage stress, exercise
 Avoid touching potentially contaminated surfaces
 Cover your nose or mouth when you sneeze or
cough
 Avoid touching your eyes, nose or mouth
 Stay home if sick
 Avoid contact with others if sick except to seek
medical care!!!
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How to CORRECTLY cover your cough
 WRONG!
Lindsay Lohan does it
(and a lot of things)
wrong.
 RIGHT!
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Preventing illness:
Receive recommended vaccinations
Talk with partners about infectious
disease history
Travel precautions – visit CDC travel
web site (www.cdc.gov/travel )
Prevention: public health
measures to mitigate potential
flu pandemic
 Local, national and international public
health programs
 Reporting and assessment
 Treatment and monitoring of treatment
compliance
 Stockpiling medications- CDC deploying 25%
of national stockpiles of antiviral
 Education
 Social distancing
 Closing schools, business, public gatherings
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Questions?
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