AVOIDING INFECTIOUS
DISEASES
Chapter 15
Chapter 15 Objectives
Explain how the different agents of infection
spread disease.
Describe how your body protects itself from
infectious disease.
List ways to protect yourself from catching a
cold or the flu and ways to feel better if you do
catch one.
Name and describe some common infectious
diseases.
Explain pandemic and describe the levels of
alert.
Name the infectious diseases for which you are
most at risk, and list your strategies for avoiding
them.
Understanding Infection
• Pathogens: Disease-causing organisms.
• Infection: A complex process, triggered by various
pathogens and countered by the body’s own defenders.
Pathogen
For
Infection
to occur
Host
Right Conditions
Agents of Infection
•Viruses
• Tiniest pathogens, but also the toughest. Consist of a bit of RNA or
DNA within a protein coat. Take over a body cell’s reproductive
machinery to reproduce.
• Examples
• Rhinoviruses and adenoviruses
• Coronaviruses
• Influenza viruses
• Herpes viruses
• Retroviruses
Agents of Infection
•Bacteria
• Simple one-celled organisms.
• Most plentiful microorganisms as well as the
most pathogenic.
• Harm the body by releasing enzymes that
digest body cells or toxins that produce the
specific effects of specific diseases.
•Fungi
• Single-celled, microscopic animals that
release enzymes and toxins that destroy
cells or interfere with their function.
Agents of Infection
•Protozoa
• Single-celled, microscopic animals that release enzymes and toxins
that destroy cells or interfere with their function.
•Helminths
• Small parasitic worms that attack specific tissues or organs and
compete with the host for nutrients.
How Do You Catch an Infection?
Animals
and
Insects
Water
People
Food
7. Termination
The Process of
Infection
6. Recovery or
Relapse
5. Clinical Stage
4. Prodromal
Period
3. Incubation
Period
2. Infection
1. Exposure
Who Is at Highest Risk for Infection?
Children and their families.
The elderly.
The chronically ill.
Smokers and those with respiratory problems.
Those who live or work in close contact with someone
sick.
Residents or workers in poorly ventilated buildings.
How Your Body Protects Itself
Tears, sweat, skin oils, saliva, mucus, and cilia.
Lymphatic System Organs and Components:
• Spleen, thymus gland, lymph nodes, and lymph vessels.
• White blood cells (WBC)
• Polymorphonuclear Cells (bacteria)
• Lymphocytes (viruses)
• Cellular immunity- macrophages, WBC
• Humoral immunity- antibodies
The Human
Lymphatic System
and Its Functions
The Immune Response
Immune Disorders
Allergies
• Hypersensitivity to a substance in our
environment or diet.
• Symptoms
• Itching, nasal congestion, eye irritation, coughing,
wheezing, hives, vomiting, and diarrhea, and even
sudden life-threatening collapse.
• Treatments
• Non-sedating oral medications, nasal sprays, and
immunology.
Immune Disorders
Autoimmune Disorders
When the immune system declares war on the cells,
tissues, or organs it normally protects.
Types
• Graves disease, systematic lupus, scleroderma,
rheumatoid arthritis and multiple sclerosis.
Causes
• Genetics, drugs, chemicals, bacteria and viruses.
Treatments
• Medications
• New diagnostic tests and treatments are on the
horizon.
Common Infectious Diseases
• Common cold
• Influenza
• Meningitis
• Hepatitis
• Mononucleosis
• Pneumonia
• Tuberculosis
• Group A and group B strep infection
• Toxic shock syndrome
• New infectious treats
Common Cold Facts
There are 200 distinct cold viruses.
 No vaccine
Americans come down with 1 billion colds annually.
The common cold results in ~20 million lost work
days and 22 million days of absence from school.
College Students (Recent Study)
• 9 out of 10 students had at least one cold or flu-like illness
during academic year.
• Spread by contact with infectious secretions
• Coughing, sneezing, hands
Common Cold Seasons
Spring, Summer, and Early Fall
• Rhinoviruses causing symptoms above the neck
• Stuffy nose, headache, and runny nose.
Winter
• Adenoviruses, parainfluenza viruses, coronaviruses, and
influenza viruses.
• These viruses are more likely to get into the bronchi and
trachea and cause more fever and bronchitis.
Caring for Your Cold
Drink plenty of fluids
Get plenty of rest
Do not take antibiotics
Do not take aspirin or acetaminophen
Influenza
Influenza—or the flu causes more severe, longer
lasting symptoms than a cold.
Fever, aches and chills
Types
• Influenza A and influenza B.
Transmission
• The flu is very contagious and is spread by coughs,
sneezes, laughs, and even normal conversation.
Vaccinations
• Annually: FluMist vs. flu shots
Anti-viral Drugs: Relenza and Tamiflu
Individuals Who Should Get Flu Shots
 Individuals aged 65 years and older.
 Residents in long term care facilities.
 Individuals aged 2 to 64 years with chronic health conditions.
 Children aged 6 to 23 months.
 Pregnant women.
 Health-care personnel.
 Household contacts and caregivers.
New recommendations:
All people should be vaccinated annually
Vaccinated children reduce spread in community
Vaccinated adults stay at work
Meningitis
An extremely serious, potentially fatal illness that attacks
the membranes around the brain and spinal cord; caused
by the bacterium Neisseria meningitis.
Can result in hearing loss, kidney failure, and permanent
brain damage.
Viral meningitis is typically less severe.
Meningitis
Symptoms
• Sudden high fever.
• Severe persistent headache.
• Neck stiffness and pain that makes it difficult to touch
the chin to the chest.
• Nausea and vomiting, sometimes diarrhea.
• Confusion and disorientation (acting “goofy”).
• Drowsiness or sluggishness.
• Pain or weakness in the muscles or joints.
• Eye pain or sensitivity to bright light.
Meningitis
Transmission
• Coughing, kissing, sharing drinks, eating utensils, or cigarettes; or
prolonged exposure to infected individuals.
Vaccinations
• Recommended for freshman living in dormitories.
• Vaccination is effective for 3-5 years against 70% of bacterial
meningitis strains.
Hepatitis
It is a an inflammation of the liver caused by at least 5
different viruses often referred to as hepatitis A, B, C,
(rarely Delta and E).
Symptoms
• Headaches, fever, fatigue, stiff or aching joints, nausea, vomiting
and diarrhea.
• Enlarged, tender liver.
• Sometimes the yellowish tinge of jaundice develops.
Hepatitis
• Transmission
• Hepatitis A: Poor sanitation. Water, food.
• Hepatitis B: Blood and other bodily fluids (sexual, tattoos)
• Can become chronic (5%)
• Hepatitis C: Exposure to infected blood, injection-drug use,
tattoos, or body piercing. Usually becomes chronic leading
to liver failure.
• Treatment
• Rest and the avoidance of alcohol and drugs that may
stress the liver.
• Alpha interferon and ribavirin, an antiviral medication. The treatment
lasts for 6 to 12 months and can be difficult to endure (only for Hep C)
• E
Before You Get a Tattoo or Piercing
Ask to see a certification that the
autoclave has been sterilized.
Make sure the artist is wearing standard
medical latex gloves.
Find out if the artist is vaccinated for
hepatitis B.
Make sure the artist uses only new
sterile needles.
Ask how the artist disposes of used
needles.
Always ask to see photos of the artist’s
finished work.
If you require prophylactic antibiotics for
dental cleanings or other procedures, do
not get a tattoo.
Epstein-Barr Virus and Infectious
Mononucleosis
Epstein-Barr virus (EBV), a member of the herpes virus
family, infects most people at some time in their lives.
Mononucleosis
• An infectious condition cased by EBV during adolescence
or young adulthood.
Transmission
• You can get mono from an infected person through kissing
or any other form of close contact.
Symptoms
• Sore throat, headache, fever, nausea, and prolonged
weakness.
• Swollen spleen, and enlarged lymph nodes and liver.
Pneumonia and Bronchitis
Pneumonia is an infection in the lungs
• Cough, fever, fatigue. May be short of breath.
• May be caused by bacteria, viruses. RX needed. Pneumococcal can be
avoided through vaccine.
• Diagnosed by listening to the lungs and taking a chest X-ray
Bronchitis is an infection in the bronchus
• Dry cough, harsh sounding, rarely fever. Chest may hurt.
• May be caused by bacteria, viruses
• Occasionally requires treatment with antibiotic
Tuberculosis
Tuberculosis is a bacterial infection of the lungs.
• About 30% of the world’s population is infected with the TB organism,
although not all develop active disease.
• Approximately 15 million Americans have the infection. Disease not as
common
Transmission
• Highly contagious, especially where inadequate ventilation increases
the risk of infection.
Symptoms
• Vary depending on the organs affected.
• Fever, sweating, unexplained weight loss, loss of appetite, fatigue,
persistent cough, difficulty breathing or chest pain when breathing.
Treatment
• A combination of 3 to 4 different antibiotics taken daily for at least 6 to
9 months.
How
Tuberculosis
Spreads
Group A Strep Infection
Group A streptococcal bacteria causes strep throat.
Toxic streptococcal shock syndrome is an invasive form of
the disease in which strep gains access to the blood.
Treatment
• Antibiotics (penicillin best). Rare resistance.
• If not treated promptly, strep bacteria (toxins) can travel to the
kidneys, the liver, or the heart, where they can cause rheumatic
fever.
Toxic Shock Syndrome
 Potentially deadly disease
 Associated with the use of tampons, particularly high-absorbency types or as a
result of leaving tampons in too long (Staph)
 Necrotizing fasciitis or “flesh eating disease” (Group A strep)
 Transmission
• Caused by Staphylococcus aureus and Group A Streptococcus pyogenes
bacteria.
Symptoms
• High fever; a rash that leads to peeling of the skin on the fingers,
toes, palms, and soles; dizziness; dangerously low blood pressure;
and abnormalities in several organ systems, and in the muscles
and blood.
Treatment
• Immediate hospitalization, IV administration of fluids, medications
to raise blood pressure, and powerful antibiotics.
• Without treatment, TSS can cause severe muscle weakness,
partial paralysis, amnesia, disorientation, and impaired lung and
kidney function. Death common.
“Superbug” Threat: MRSA
MRSA
• Methicillin Resistant Staphylococcus Aureus (SA)
• SA strain that is resistant to methicillin.
• Looks like “spider bite”
• Treated with oral antibiotics or draining abscesses
Risk
• MRSA infections are now community acquired rather than being
highest in hospitals and health-care facilities.
• Can develop among sports teams, child-care attendees, and prison
inmates.
• Person to person transmission by direct contact
Reproductive and Urinary Tract Infections
Vaginal Infections
Trichomoniasis
Candidiasis
Bacterial Vaginosis
Urinary Tract Infections
Urethritis
Cystitis
Pyelonephritis
H1N1 Virus and Influenza
H1N1 flu was a new influenza type A virus detected in
people in spring 2009.
 Spread rapidly around the world due to mutation that shifted the
amino acids in the coating of the virus
 Caused more deaths in healthy people
 High rates of death in children
 Now included in the annual vaccine
Spreads from person to person through coughing or
sneezing.
Symptoms similar to the symptoms of the regular flu.
Threat of a Pandemic
The World Health Organization has
developed a global influenza preparedness
plan, which defines 6 distinct phases of a
pandemic.
Concern with major mutation of Influenza
virus and rapid spread
Globalization with air travel, etc.
New Infectious Threats
• Severe Acute
Respiratory Syndrome
(SARS)
• Bioterror Threats
• Anthrax
• Smallpox
• Botulism
• Tularemia
Three Steps to Infection Protection
Immunizations
Good Health Habits
Prompt Treatment
Recommendations for Adult Immunizations
Tetanus, Diphtheria, Pertussis
Hepatitis B
Hepatitis A
Measles, Mumps and Rubella
Varicella (Chickenpox)
Meningococcal Disease
Influenza
Pneumococcal Disease
2012 ACIP Adult Immunization Schedule, AgeBased Recommendations
How to Protect your Health
• Healthy habits
• WASH YOUR HANDS!!!!
• SNEEZE INTO YOUR ELBOW
OR USE A TISSUE
• DON’T COME TO SCHOOL OR
GO TO WORK WHEN SICK
• DON’T SHARE THINGS