Intro to Health Careers

Infection Control

  1. The main goal of infection control is to prevent the spread of infectious diseases
  2. Infectious disease – any disease that is caused by the growth of pathogens (disease causing microorganisms in the body).
  3. Types of Infections
  4. Generalized (systemic) – affecting the whole body
  5. Signs and symptoms include headaches, fever, fatigue, vomiting, diarrhea, increased pulse and respirations
  6. Localized – affecting one area of the body
  7. Signs and symptoms include the area being red, swollen, warm to touch and painful. There may also be drainage.
  8. Microbiology
  9. Microorganism – very small (usually 1 celled) living thing.
  10. Microbiology – the study of microorganisms
  11. Germ Theory – specific microorganisms (called bacteria) are the cause of specific diseases in both humans and animals.
  12. In 1843 a scientist named Oliver Wendell Holms published an article that stated Communicable Diseases (a disease that may be transmitted either directly or indirectly from one individual to another) might be spread by the contaminated hands of doctors and nurses.
  1. It was observed that mortality rates were higher when patients were attended to by doctors or medical students who came from the morgue or autopsy rooms without first washing their hands
  1. Not all microorganisms are harmful; many commonly reside on or in the body. These are called normal flora.
  2. Some microorganisms are necessary to maintainnormal function.
  3. E. coli aids the digestive process in the colon, but can be a pathogen and create an infection when it invades an area of the body where it is not a part of the normal flora.
  4. Some microorganisms normally live on the body but have no beneficial role. They normally do no harm unless the individual becomes susceptible to infection.
  5. Immunosuppressant
  6. Long-term antibiotic use
  7. Opportunistic infection – an infection that occurs due to the weakened physiological state of the body


Introduction to Health Careers

Unit 10 – Infection Control

Types of Microbes

Microbes – pathogenic microorganisms

Classified as bacteria, viruses, fungi, rickettsia and protozoa

  1. Bacteria – one celled organisms that can be pathogenic or nonpathogenic
  2. Toxin – poisonous substance produced by many bacteria
  3. Colony – a group of bacteria that grow together
  4. Categorized according to shape
  5. Cocci (round or ovoid shaped) -
  6. Micrococci – appear singly
  7. Cause skin and wound infections
  8. Diplococci – appear in pairs
  9. Cause gonorrhea, meningitis and some types of pneumonia
  10. Staphylococci – appear in irregular clusters
  11. Are pus-producing and can cause abscesses, boils, wound infections, UTIs and other types of pneumonias
  12. Streptococci – form chains
  13. Cause rheumatic fever and strep throat.
  14. Bacilli (rod shaped) – the cause of diseases such as tuberculosis, tetanus, pertussis, botulism, diphtheria and typhoid fever
  15. Bacilli – appear singly
  16. Coccobacilli – somewhat oval
  17. Diplobacilli – appear in pairs
  18. Streptobacilli – attached end to end to form chains
  19. Spiral Shaped – cause diseases such as syphilis and cholera
  20. Vibrios – curved rods
  21. Spirilla – organism is rigid
  22. Spirochetes – organism is flexible
  23. Viruses – the smallest microbes. Cannot be seen under the traditional light microscope
  24. Obligate intracellular parasites – viruses can only live inside another organism and depend on other cells for food, nutrients and means of reproduction
  25. Cause diseases such as the common cold, influenza, pneumonia, chickenpox, croup, hepatitis, AIDS, measles, mumps, herpes, warts and polio
  26. Viral infections are difficult to treat because they multiply rapidly, are easily transmitted, resistant to many disinfectants and are not killed by antibiotics.
  27. Fungi – large group of simple plants. There are two groups that are potential pathogens: Yeast – one celled; Molds – multicellular

**Cannot produce their own nutrients so they live on other organic materials.

**Cause diseases such as athlete’s foot, ringworm, skin and scalp infections.

  1. Rickettsia – much smaller than bacteria and have rod or spherical shapes.
  2. Must live inside the cell of another organism
  3. Passed through the bite of fleas, lice, ticks and mites
  4. Typhus is the only infection transmitted by humans
  5. Protozoa – the only microorganism classified as an animal
  6. Found throughout the human body on the skin, intestines and the mucous membranes of the nose and throat
  7. Also found in decayed material, water contaminated with sewage waste, food washed in contaminated water or handled by unwashed hands.
  8. Cause diseases such as: dysentery (gastrointestinal), trichomoniasis (STD), Toxoplasmosis, pneumocystic pneumonia (common cause of death in AIDS patients) and malaria


Intro to Health Careers

Chapter 10 – Infection Control

The Chain of Infection

The chain of infection is a useful model for explaining how infectious diseases occur and are transmitted. It consists of 6 elements that must be present for an infection to develop

  1. Infectious Agent – a pathogen must be present
  2. Reservoir Host – the pathogen must have a place to live and grow
  3. Ex. Human body, contaminated water or food, animals, insects…
  4. Portal of Exit – the pathogen must be able to escape from the reservoir
  5. Ex. Blood, urine, feces, broken skin, wound
  6. Means of Transmission – the pathogen must have a way of traveling to the new host
  7. Ex. Air, food, direct contact with infected person
  8. Portal of entry – the pathogen must have a way of entering the new host
  9. Ex. Nostrils, mouth, breaks in skin
  10. Susceptible host – an individual who has a large number of pathogens invading the body or someone that does not have adequate resistance to the invading pathogen.

The Body’s Defense Mechanisms – if the body’s mechanisms are intact, along with a strong immune system, an individual can resist the microorganism and not become ill. Examples of the body’s natural defense systems:

  1. Cilia in the Respiratory Tract – catch and move pathogens out of the body
  2. Coughing and sneezing to propel pathogens outward
  3. Tears which contain chemicals to kill bacteria
  4. Hydrochloric Acid in the stomach which destroys pathogens
  5. Mucous membranes which trap pathogens
  6. Fever to kill microorganisms
  7. Production of White Blood Cells to destroy pathogens

Prevention through Asepsis – The practice of asepsis, or aseptic technique, involves methods used to make the patient, the worker and the environment pathogen free.

  1. Medical Asepsis (clean technique) – includes procedures to decrease the number and spread of pathogens in the environment
  2. Ex. Hand washing, good personal hygiene, cleaning of rooms between patient use, disposal of gloves and other contaminated equipment.
  3. Surgical Asepsis (sterile technique) – includes procedures to completely eliminate the presence of pathogens from objects and areas
  4. Ex. Wearing sterile caps, gloves, masks and gowns during surgery, sterilizing equipment, changing dressings and disposing of contaminated materials

Breaking the Chain of Infection – if you break just one link in the chain of infection, the spread of infection will be stopped. The best ways to do this are:

  1. Decrease the source of microorganisms
  2. Proper hand washing, decontaminate surfaces and equipment, avoid contact with patients when you are ill.
  3. Prevent the transmission of microorganisms
  4. Wear Personal Protective Equipment (PPE), follow isolation procedures
  5. Maximize resistance of the host
  6. Provide good hygiene

  1. e, ensure proper nutrition, decrease stressors that weaken the immune system

Intro to Health Careers

Chapter 10 – Infection Control

Standard Precautions

Standard Precautions – specific procedures developed by the CDC to help prevent contact with potentially hazardous body fluids

These fluids include:

  • Blood
  • All body fluids and secretions (except sweat)
  • Broken Skin
  • Mucous Membranes
  • Unidentified Fluids

These precautions include:

  • Handwashing
  • When coming on duty
  • When taking a break or leaving work
  • Between patient contact
  • Before and after wearing gloves
  • Before and after touching face
  • After contact with suspected contaminated item
  • Before and after eating, drinking or using the bathroom
  • Personal Protective Equipment (PPE)
  • Gloves
  • Mask/Eye Protection/Face Shield
  • Gown
  • Proper Disposal of Materials
  • Waste
  • Patient Materials
  • Linens
  • Sharps