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.