An Invitation to Health
Prepared by: Karlyn Grimes MS RD
Chapter 14: Defending Yourself Against
Infectious Disease
Chapter 14 ObjectivesExplain how different agents of infection spread disease.
Describe how your body protects itself from infectious disease.
List and describe some common infectious diseases.
Identify sexually transmitted infections and the symptoms and treatments of each.
List the methods of STI transmission.
Define HIV infection and describe its symptoms.
Explain some practical methods for preventing HIV infection and other sexually transmitted infections.
Agents of InfectionViruses
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.
BacteriaSimple one-celled organisms. The most plentiful
microorganisms as well as the most pathogenic. Bacteria harm the body by releasing enzymes that digest body
cells or toxins that produce the specific effects of specific diseases.
FungiSingle-celled or multi-celled organisms composed of
threadlike fibers and reproductive spores. Fungi release enzymes that digest cells in hair-covered areas of the
body.
ProtozoaSingle-celled, microscopic animals that release enzymes
and toxins that destroy cells or interfere with their function.
HelminthsSmall parasitic worms that attack specific tissues or
organs and compete with the host for nutrients.
How Do You Catch An Infection?
Animals
and
Insects
PeopleWater
Food
How do infections occur?
• Pathogens • Virus• Bacteria• Fungi• Protozoa• Rickettsia
Body has normal resistance to most pathogens
4 Ways to Enter the Body
Direct
Indirect
Airborne
Vector-borne
Fluid to Fluid
Infected Surface
Water Vapor
Non-human Carrier
For Infection to Occur…
• Pathogen
• Quantity
• Vulnerability
• Entry Site/Mode
The Process of Infection
1. Exposure
2. Infection
3. Incubation Period
4. ProdormalPeriod
5. Clinical Stage
6. Recovery orRelapse
7. Termination
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.– Lymphocytes (white blood
cells)
Fig. 14-1, p. 395
Right lymphatic duct• Drains right upper portion of body
Thoracic duct• Drains most of body
Some of the lymph vessels• Return excess fluid and reclaimable solutes to the blood
Some of the lymph nodes• Filter bacteria and many other agents of disease from lymph
Tonsils• Defense against bacteria and other foreign agents
Thymus gland• Site where certain white blood cells acquire means to chemically recognize specific foreign invaders
Spleen• Site where antibodies are manufactured; disposal site for old red blood cells and foreign debris; site of red blood cell formation in the embryo
Bone marrow• Marrow in some bones are
production sites for infection-fighting blood cells (as well as red blood cells and platelets)
Lymph nodes• Store protective cells and destroy pathogens
The Human Lymphatic System
Immune DisordersAllergies
• 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 DisordersAutoimmune 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.
Recommendations for Adult Immunizations
Tetanus, Diphtheria
Hepatitis B
Hepatitis A
Measles, Mumps and Rubella
Varicella (Chickenpox)
Meningococcal Disease
Influenza
Pneumococcal Disease
Who Is At Highest Risk of Infectious Disease?
Children &Their Families
The ChronicallyIll
Residing In PoorlyVentilated Buildings
Smokers & ThoseWith Respiratory
Problems
The Elderly
IndividualsWorking With
Sick Individuals
Common Infectious Diseases
• Common Cold• Influenza• Meningitis• Hepatitis• Mononucleosis• Chronic Fatigue Syndrome (CFS)• Pneumonia• Tuberculosis• Group A and Group B Strep Infection• Toxic Shock Syndrome• Insect- and Animal-Borne Infections• New Infectious Treats
Common Cold Facts
• There are 200 distinct cold viruses.• 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.Spring, Summer and Early Fall Colds
– Rhinoviruses causing symptoms above the neck• Stuffy nose, headache and runny nose.
Winter Colds– 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.
Treatments for the Common Cold
Limit Aspirin and Acetaminophen (Tylenol)• Suppresses important antibodies and increases
symptoms.• Reye’s syndromeIbuprofenAntihistamines• Watch for drowsiness• Individuals with high blood pressure, diabetes,
heart disease, or thyroid disorders should limit products containing pseudoephedrine.
Limit Multisymptom MedicationsAlternative Remedies• ? Vitamin C, Echinacea, zinc lozenges
Influenza
Facts •The flu causes more severe, longer lasting symptoms than a cold.
•Influenza A and influenza B.
Influenza
Transmission •The flu is very contagious and is spread by coughs, sneezes, laughs, and even normal conversation.
Influenza
Vaccinations •Annually: FluMist vs. flu shots
•Not for individuals who are allergic to eggs.
Influenza
Antiviral 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.
Student Snapshot, p. 402
Rate of Flu in College Dorms
Fig 14-3, p. 402
MeningitisFacts •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.
MeningitisSymptoms •Rash, fever, severe headache,
nausea, vomiting, and lethargy.
MeningitisTransmission •Coughing, kissing, sharing drinks,
eating utensils, or cigarettes; or prolonged exposure to infected individuals.
MeningitisVaccinations •Recommended for freshman living
in dormitories.• Vaccination is effective for 3 years against 70% of bacterial meningitis strains.
Hepatitis
Facts •Five different viruses (hepatitis A, B, C, Delta and E) that can cause inflammation of the liver.
Hepatitis
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•Hepatitis B: Blood and other bodily fluids
•Hepatitis C: Exposure to infected blood, injection-drug use, tattoos, or body piercing.
Hepatitis
Treatments •Rest, a high-protein diet, and the avoidance of alcohol and drugs that may stress the liver.
•Alpha interferon.
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.
Mononucleosis
Facts •A viral disease that targets people 15-24 years old.
•You can get mono through kissing or any other form of close contact.
Mononucleosis
Transmission •You can get mono through kissing or any other form of close contact.
Mononucleosis
Symptoms •Sore throat, headache, fever, nausea, and prolonged weakness.
•Swollen spleen, and enlarged lymph nodes and liver.
Mononucleosis
Treatment •Rest
Chronic Fatigue Syndrome
Facts •As many as 500,000 Americans have an array of symptoms known as chronic fatigue syndrome (CFS).
Chronic Fatigue Syndrome
Common Characteristics
•Immune abnormalities, such as high levels of certain immune cells (B lymphocytes and cytokines) that act as if they were constantly battling a viral infection.
Chronic Fatigue Syndrome
Diagnosis •Unavailable at this time.
Pneumonia
Facts •An inflammation of the lungs caused by bacteria, viruses (including flu), or foreign material in the lungs (such as smoke).
•The 5th leading killer of Americans.
Pneumonia
Signs •Cough, a fever of more than 101ºF, difficulty breathing, chills, and excessive yellow-green phlegm.
Pneumonia
Symptoms •Bacterial Pneumonia: fever, shortness of breath, and general weakness.
Pneumonia
Treatment •Antibiotics and occasionally hospitalization.
Pneumonia
Vaccination •Recommended for those who’ve had pneumonia in the past, those with impaired immune function, and those over age 65.
Tuberculosis
Facts •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 disease.
Tuberculosis
Transmission •Highly contagious, especially where inadequate ventilation increases the risk of infection.
Tuberculosis
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.
Tuberculosis
Treatment •A combination of three to four different antibiotics taken daily for at least 6 to 9 months.
Fig. 14-4, p. 405
When someone withactive tuberculosisexhales, coughs, orsneezes, tuberculosisis expelled in tinyairborne droplets thatothers may inhale.
The TB bacterialodge mainlyin the lungs,where theyslowly multiply,creating patches,then cavities, inthe lungs.
Other parts ofthe lung areaffected, includingbronchi and thelining of the lung.
If untreated, TB can eventually spread to anddamage the brain, bone, eyes, liver and kidneys,spine, and skin.
How Tuberculosis
Spreads
Group A and Group B Strep Infection
Facts •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.
•Group B streptococcus (GBS) is the leading cause of life-threatening perinatal infections in the United States.
Group A and Group B Strep Infection
Treatment •Group A: Antibiotics (penicillin or Omnicef)
– If not treated promptly, strep bacteria can travel to the kidneys, the liver, or the heart, where they can cause rheumatic fever.
•Group B: Antibiotics during and prior to childbirth.
Toxic Shock SyndromeFacts •A potentially deadly disease associated with the use of
tampons, particularly high-absorbency types, and women who have given birth within the preceding six to eight weeks.
•Caused by Staphylococcus aureus and Group A Streptococcus pyogenes bacteria.
Toxic Shock SyndromeSymptoms •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.
Toxic Shock SyndromeTreatment •Immediate hospitalization, IV
administration of fluids, medications to raise blood pressure, and powerful antibiotics.
•Without treatment, TSS can cause severe and permanent damage, including muscle weakness, partial paralysis, amnesia, disorientation, an inability to concentrate, and impaired lung and kidney function.
Insect and Animal Borne Infections
Infection CharacteristicsLyme Disease
• A bacterial infection spread by ticks carrying the a bacterium called Borrelia burgdorferi.
• Symptoms include joint inflammation, heart arrhythmias, blinding headaches, and memory lapses.
Insect and Animal Borne Infections
Infection Characteristics
West Nile Virus
• A virus transmitted by a mosquito that feeds on an infected bird and then bites a human.
• MNV interferes with normal central nervous system functioning and causes inflammation of brain tissue.
• No treatment is available.
Insect and Animal Borne Infections
Infection Characteristics
Monkeypox Virus
• A rare viral disease common to Africa.
• Signs and symptoms are similar to those of small pox.
• There is no specific treatment.
The Best Defense
• Eat a balanced diet.• Avoid fatty foods.• Get enough sleep.• Exercise regularly.• Don’t smoke.• Control your alcohol intake.• Wash your hands frequently.• Don’t share food, drinks,
silverware or glasses.• Spend as little time as possible in
crowds.• Use tissues rather than
handkerchiefs.• Avoid irritating air pollutants.• Get tested immediately if you think
you have an STI.