Disease and Disease-Producing Organisms

Chapter 5

Objectives

Define disease and list seven categories of disease List 7 predisposing causes of disease Define terminology used in describing and treating disease Define complementary and alternative medicine and give examples Explain methods by which microorganisms can be transmitted List 4 types of organisms studied in microbiology and give characteristics List some diseases caused by each type Define normal flora and explain the value Describe the 3 types of bacteria by shape List several diseases in humans caused by worms Give some reasons for the emergence and spread of microorganisms Describe several public health measures Differentiate between sterilization, disinfection and antisepsis Describe techniques included as part of body substance precautions List some antimicrobial agents and how they work Describe several methods used to identify microorganisms in the lab

What is disease?- It is an illness, an abnormal

state in which part or all of the body does not function properly

CATEGORIES - Infection - Degenerative - Nutritional - Metabolic - Immune - Neoplasms - Psychiatric

Predisposing Causes of Disease

Age Gender Heredity Living conditions and habits Emotional disturbance Physical and Chemical damage Preexisting Illness

REMEMBER : A predisposing cause may not actually cause the disease, but increases the probability of a person becoming ill.

The Study of Disease

Click icon to add picture

Definitions Pathophysiology Etiology Acute Chronic Subacute Idiopathic Iatrogenic Epidemiology Incidence Prevalence Mortality Epidemic Endemic Pandemic

Treatment and

Prevention of Disease

Diagnosis – determination of the nature of the illness

Need to know symptom, sign, syndrome, prognosis, therapy and prevention

CAM is defined as methods of disease prevention and treatment used along with traditional medicine (Examples include: chiropractic, acupuncture, biofeedback)

Infectious Disease Microorganisms are the predominant

cause of disease in the human body.

Parasite – organism that liveson or within a host at host’s expense

Pathogens Pathogens are disease causing

organism and infection is an invasion of

pathogens that have adverse effects

(An infection can be local or systemic.)

Opportunistic infection Communicable infection

Modes of Transmission Disease can be spread directly or

indirectly.

Portals of entry : skin, respiratory, digestive, urinary and reproductive systems

MicrobiologyThe study of microorganisms

*** Bacteria, Viruses, Fungi, Protozoa

BacteriaSingle-cell organism whose genetic

material is not enclosed in a membrane. (No true nucleus)

Can grow with or without oxygen Resistant forms are called endospores Flagella Pili

Bacteria cont. Shape and Arrangement : Cocci,

Bacilli, Curved rods

Others : Rickettsia and Chlamydia

Diseases caused by bacteria : Pneumonia, Tuberculosis, Syphilis, Lyme disease, Typhus

VirusesObligate parasite that can only reproduce

in living cells. Contain genetic material.

Not susceptible to antibiotics.

Classified according to the type of nucleic acid they contain (DNA or RNA) and the type of disease they cause.

Named according to where they were isolated, the symptoms they cause, the host, or the vector that carries them.

Viruses cont. Prions and Viroids

Much smaller than bacteria

Diseases caused by viruses : Measles, Influenza, Chickenpox, Common Cold

FungiSimple plant-like organism.

2 types : Yeasts and Molds

Yeast – single cell

Mold – filamentous

Diseases caused by fungi : Ringworm, Thrush, Pneumonia

ProtozoaSingle-cell, animal-like microbes

Amebas Ciliates Flagellates Sporozoa What you will see: Giardia (Flagellate)

Parasitic Worms

They are parasites with human hosts

Roundworms (ascaris,pinworms, hookworms)

Flatworms (tapeworms, flukes) Infection by worms is called infestation.

Microbial ControlInfectious disease increasing due to

various factors.

Increased population & travel, disruption of animal habitats, changes in food handling

Microbes and Public Health : sewage and garbage, water purification, prevention of food contamination, milk pasteurization

Aseptic Methods : sterilization, disinfection, antisepsis

Infection Control HANDWASHING. HANDWASHING.

HANDWASHING……. Universal techniques, sharps safety,

specific “precautions” OSHA Antimicrobial Agents : antibiotics,

antiviral, antifungal, antiparasitic

ANTIBIOTICS/MRSA Antibiotic is used to kill bacteria.

Derived from fungi and soil bacteria. Usage can be harmful Antibiotic-resistance

Lab Identification of Pathogens

Blood, Spinal Fluid, Feces, Urine, and Sputum most frequently studied.

Bacterial Isolations and Tests Staining Techniques Other techniques

Freebie… What will you see clinically : - Know antibiotics - MRSA - Infection Control