Infection Control
Basic Principals of Infection Control • How disease is transmitted and the main ways to prevent transmission. • Microorganisms are small living organisms invisible to the naked eye • Two types of microorganisms 1. Pathogens 2. Nonpathogens
What are microorganisms? • Microorganisms are small living organisms invisible to the naked eye • There are five classes of microorganisms • Bacteria, protozoa, fungi, rickettsiae, and viruses.
Classifications of microorganisms • Bacteria – cocci round MRSA, strepthroat bacilli rods i.e. TB, pertussis, botulism spirilla spirals i.e. syphilis, cholera • Protozoa- one cell animal-like i.e. malaria • Fungi – plant-like organisms i.e. Yeasts, molds i.e. Ringworm, thrush etc.
Microorganisms (cont.) • Rickettsiae- parasitic i.e. Lice, ticks, fleas • Viruses - cannot reproduce without a cell, major risk to healthcare workers and are blood borne: • Examples of viruses, Hepatitis C, Hepatitis B, HIV.
Factors for Growth of Microorganisms • Most prefer warm, moist or wet, dark environment i.e. the human body • Oxygen needs vary anaerobic no oxygen aerobic needs oxygen
Pathogenic microorganisms • Cause diseases in different ways • produce poisons toxins • allergic reactions • attack and destroy the cells • antibiotics are effective against bacteria not against viruses
Classes of Diseases and Infections • Endogenous inside the body i.e. tumors, congenital disorders • Exogenous outside the body i.e. trauma, electric shock
Classes of Diseases and Infections (cont) • Nosocomial acquired in healthcare facilities i.e. Staph MRSA, pseudomonas • Opportunistic infections that only affect the immunosuppressed i.e. Kaposi’s sarcoma, pneumocystis carnii
ChainofInfection • Causative agent (pathogen, bacteria, virus) • Reservoir (place to live) i.e. human body. • Portal of exit (the way the pathogen escapes) i.e. urine, feces, secretions • Mode of transmission (transmitted to a reservoir or a host) Direct or Indirect
Mode of Transmissions • Direct person to person sexual contaminated hands • Indirect touching contaminated equipment breathing droplets insect bites
Chain of Infection (cont.) • Portal of Entry a way to enter a new host or new reservoir i.e. respiratory tract, breaks in the skin etc. • Susceptible Host anyone who can contract the disease weak immune systems anyone with a breakdown in defense mechanisms
Infectious Agent Susceptible Host Reservoir Portal of Exit Portal of Entry Mode of Transmission
Ending the chain • Breaking the chain Use aseptic technique asepsis Best is hand washing • Levels or types of asepsis antiseptics, disinfection, sterilization Antiseptics used in healthcare alcohol and betadine
Bacteria One celled organism Multiply rapidly Classified by shape:
Cocci Round or spherical in shape Types: Diplococci-occur in pairs-cause gonorrhea, meningitis and pneumonia
Diplococci Occur in pairs-cause gonorrhea, meningitis and pneumonia
Streptococci Occur in chains Cause-strep throat
Staphylococci Occur in clusters or groups Most common pyogenic(pus producing) Cause- boils, wound infections and toxic shock
Bacilli Rod shaped Occur singly, pairs or in chains Many have flagella which are threadlike projections that allow them to move Can form spores (thick walled capsules) when conditions for growth are poor which make them DIFFICULT to kill!!! Cause-tuberculosis, tetanus, pertussis (whopping cough)
Spirilla Spiral or corkscrew in shape Cause-syphilis and cholera
Protozoa One celled animal-like organisms Found in decayed materials and contaminated water May have flagella Cause-malaria, trichomonas
Fungi Simple plant-like organisms that live on dead organic matter Yeast and molds are common forms Cause-ringworm, athletes foot, yeast vaginitis and thrush
Rickettsiae Parasitic Microorganisms Cannot live outside the cells of another living organism Found in fleas, lice, ticks and mites Transmitted to humans by the bites of these insects Cause-Typhus Fever, Rocky Mountain Spotted Fever
Viruses Smallest microorganisms Cannot reproduce unless inside another living cell Spread from human to human by blood or other body secretions Resistant to many disinfectants and not affected by antibiotics Cause-Common cold, measles, chickenpox herpes, warts, influenza
3 Viruses of Major Concern Hepatitis B-transmitted by blood, serum and other body fluids-affects the liver-has a vaccine Hepatitis C-transmitted by blood and blood containing body fluids-no symptoms or flu like symptoms-cause liver damage-vaccine being developed Acquired Immune Deficiency Syndrome-caused by HIV virus-suppresses immune system-no cure or vaccine
