Definition of Normal Flora • Population of microorganisms that inhabit the skin of mucous membranes of healthy normal persons • Also referred to as indigenous species or indigenous microbiotaActinomyces israelii, part of the normalflora of the oral cavity.
RESIDENT FLORA• Fixed types of microorganisms regularly found in a given area at a given age• If disturbed, it promptly reestablishes itself/ transient microorganisms may colonize, proliferate and produce disease• More important
TRANSIENT FLORA• Non-pathogenic or potentially pathogenic microorganisms that inhabit the skin or mucous membranes for hours, days, or weeks• Derived from the environment, does not produce disease• Does not establish itself permanently on the surface• Little significance
ROLES1. Protective host defense by maintaining conditions such as pH so other organisms may not grow2. Synthesize vitamin K and B
Where the Normal Flora Are Found • Skin • Conjunctiva • Nasopharynx • Oral cavity • Gastrointestinal tract and rectum • Urogenital tract
NORMAL FLORA- SkinSITE COMMON/ LESS COMMON BUT MEDICALLY NOTABLE IMPORTANT ORGANISMS ORGANISMSCutaneous surfaces Staphyloccocus Staphyloccocus aureus,including urethra and epidermidis Corynebacteriaouter ear (diphteroids) Streptococci, Anaerobes e.g. Peptostreptococci, Yeast (Candida sp.) Staphylococcus epidermidis, invariably found on skin and nasal membranes.
Factors that are Important in EliminatingNon-resident microorganism from the Skin1. Low pH2. Fatty acids (sebaceous secretions)3. Lysozyme Neither profuse sweating nor washing and bathing can eliminate or significantly modify the normal resident flora
Normal flora of the skin:staphylococci, corynebacteria Benefit Harm • Inhibit fungal growth Body odor (athlete’s foot) Acne • Body odor Opportunistic infections
Normal flora – UPPER RESPIRATORY TRACTSITE COMMON/ LESS COMMON BUT MEDICALLY NOTABLE IMPORTANT ORGANISMS ORGANISMSNOSE Staphyloccocus aureus Staphyloccocus epidermidis, Corynebacteria (diphteroids) Assorted Streptococci,Oropharynx Viridans streptococci Assorted streptococci, including Streptococcus nonpathogenic mutans Neisseria, nontypeable Haemophilus influenzae
Normal flora- Oropharynx• Normally sterile at birth but maybe contaminated by passage through the birth canal• Within 4-12 hours after birth, viridans stre become established as the most prominent members of the resident flora and remains so for life
Normal flora- Oropharynx• If large numbers are introduced into the bloodstream (following tooth extraction or tonsillectomy) they may settle on deformed/ prosthetic heart valves and produce endocarditis• Aspiration of saliva (containing 1012 of these organism and aerobes) ma result in necrotizing pneumonia, lung abscess, and empyema
Normal flora of the oral cavity: streptococci and lactic acid bacteria Benefit Harm• Compete with • Plaque formation pathogens for and dental disease colonization sites• Produce substances that inhibit pathogens• Stimulate local immunity
Normal FloraSITE COMMON/ LESS COMMON BUT MEDICALLY NOTABLE IMPORTANT ORGANISMS ORGANISMSGingival crevices Anaerobes, Prevotella, Fusobacterium, Streptococcus, ActinomycesStomach NONE Acidity keeps the number of microorganisms at minimum 103-105 unless obstruction at the pylorus favors the proliferation of gram-positive cocci and bacilli
Normal flora of GI tract - stomachHelicobacter pylori Harm • Causes gastric ulcers • Probable Helicbacter pylori association with duodenal ulcers
Normal Flora- COLONSITE COMMON/ LESS COMMON BUT MEDICALLY NOTABLE IMPORTANT ORGANISMS ORGANISMSColon INFANTS Lactobacillus,(microaeropjilic/ Breast-fed: Streptococci,anaerobic) Bifidobacterium Eubacterim, Bottle-fed: Fusobacterium,**sterile at birth, but mixed flora, less Lactobacillus, assortedorganisms are soon lactobacilli gram-negativeintroduced with food ADULTS Anaerobic rods, Bacteroides Enteroccocus faecalis (predominant) and other streptococcus Escherochia Bifidobacterium
Normal flora of GI tract: SMALL INTESTINEstreptococci, lactobacilli, enterococci, enterics,anaerobic rods and cocci Benefit Harm • Production of • Possible relationship with vitamins and inflammatory conditions nutrients • Transfer antibiotic • Competition with resistance to pathogens pathogens for colonization sites • Production of substances that inhibit pathogens
Normal flora of GI tract: LARGE INTESTINEBacteroids, clostridia, bifidobacteria, lactic acidbacteria, enterococci, enterics Benefit Harm • Competition with • Relationship with pathogens for inflammatory bowel colonization sites diseases • Production of • Production of substances that carcinogens and inhibit pathogens relationship with colon • Stimulate cancer development and • Methanogenesis activity of immune system
Normal flora of the VAGINA -during child-bearing years: lactobacilli and otherlactic acid bacteria Benefit Harm • Competition with • none pathogens for colonization sites • Production of lactic acid that inhibits pathogenic bacteria and yeasts
Overall benefits of the normal flora Synthesis and excretion of vitamins used by the host Competition with pathogens for nutrients and colonization sites Direct antagonism against pathogens Stimulate the development of immunological tissues Stimulate the activity of the immune system by production of natural antibodies
Overall harmful effects of the normal flora • Competition with host for nutrients • Bacterial synergism between normal flora and potential pathogens • Low grade toxemia produced in host • Endogenous disease and opportunistic infection
Defense Mechanisms • A number of defense mechanisms exist outside and in the body to break the chain, including decreasing the sources of microorganisms; preventing the transmission of microorganisms; and maximizing the host’s resistance to the microorganism
Body’s natural defenses toeliminate/kill pathogens • Cilia - in respiratory tract, catch and move pathogens out of the body • Coughing/sneezing, to propel pathogens outward • Tears - contain chemicals to kill bacteria • Hydrochloric acid in stomach • Rise in body temperature (fever) • Leukocyte (white blood cell) production increases, to destroy pathogens
Chain of infection• Model of infectious disease transmission• Six elements must be present for an infection to develop 1. The infectious agent 2. Reservoir host 3. Portal of exit from the host 4. Route of transmission 5. Port of entry 6. Susceptible host
Chain of infection Infectious agent Susceptible Reservoir host Host Portal of entry Portal of exit Route of transmission
Chain of infection 1. Infectious agent: a pathogen must be present 2. Reservoir host: the pathogen must have a place to live and grow – the human body, contaminated water or food, animals, insects, birds, dead or decaying organic material. • Humans who can transmit infection but how no signs of the disease are called carriers. Person may be unaware they are a carrier.
Chain of infection 3. Portal of exit: the pathogen must be able to escape from the reservoir host where it has been growing. • Examples of portals of exit are blood, urine, feces, breaks in the skin, wound drainage, and body secretions like saliva, mucus and reproductive fluids
Chain of infection 4. Route of transmission: When the pathogen leaves the reservoir host through the portal of exit, it must have a way of being transmitted to a new host. • Examples of routes of transmission are air, food, insects, and direct contact with an infected person
Chain of infection 5. Portal of entry: The pathogen must have a way of entering the new host. Common ports of entry are the mouth, nostrils, and breaks in the skin 6. Susceptible host: An individual who has a large number of pathogens invading the body or does not have adequate resistance to the invading pathogen will get the infectious disease
Breaking the chain of infection • Breaking at least one link stops the spread of infectious disease 1. The infectious agent • early recognition of signs of infection • Rapid, accurate identification of organisms 2. Reservoir host • Medical asepsis • Standard precautions • Good employee health • Environmental sanitation • Disinfectant/sterilization
Breaking the chain of infection 3. Portal of exit from the host • Medical asepsis • Personal protective equipment • handwashing • Control of excretions and secretions • Trash and waste disposal • Standard precautions
Breaking the chain of infection 4. Route of transmission • Standard precautions • Handwashing • Sterilization • Medical asepsis • Air flow control • Food handling • Transmission-based precautions
Breaking the chain of infection 5. Portal of entry • Wound care • Catheter care • Medical asepsis • Standard precautions 5. Susceptible Host • Treating underlying diseases • Recognizing high-risk patients
Stages of Infectious Process • Incubation period – period begins with active replication but with no symptoms • Prodromal stage – Symptoms first appear • Acute phase – proliferation and dissemination of pathogens
Stages of Infectious Process (CONT)• Convalescent stage - containment of infection and pathogens are eliminated • Resolution – total elimination of pathogens without residual manifestation Nosocomial infection – Infection acquired in a health care setting. – Typically manifest after 48 hrs. – UTI most common type
FACTORS AFFECTING RISKOF INFECTION• AGE• HEREDITY• LEVEL OF STRESS• NUTRITIONAL STATUS• CURRENT MEDICAL THERAPY• PRE-EXISTING DISEASE• IMMUNIZATION STATUS
Standard precautions• Blood• All body fluids, secretions, excretions,• Non-intact skin• Mucous membranes• Essential elements: • Use barrier protection • Prevent inadvertent percutaneous exposure, dispose of needles • Immediate and thorough hand washing
Infection control• Goal of infection control is to prevent the spread of infectious diseases• Infectious disease is any disease caused by the growth of pathogens in the body• Pathogens are disease-causing microorganisms (germs)• Infectious diseases can cause unnecessary pain, suffering and death
Maintain a safe environment • Follow specific polices and procedures designed to reduce risk of transferring infectious diseases • Prevent pathogens from being transmitted: • Patient to client, staff to client, client to staff, staff to staff • Improperly cleaned instruments and equipment
InfectionInfection can be:• Generalized or systemic (throughout the body)• Localized (affecting one part of the body)Signs and symptoms of infection:• Systemic: headaches, fever, fatigue, vomiting, diarrhea, increased pulse and respiration• Localized: redness, swelling, painful, warm to the touch
Infection Control in In-PatientHealth Care Agencies• Hand Hygiene• Patient Placement• Protective Equipment• Proper disposal of Soiled Equipment
Infection Control In Community –Based Setting• Sanitation• Proper Disposal of Waste• Food Preparation• Report CD Occurrence
Scope of the problem • Health care facilities or “sick care buildings” have higher concentration of microorganisms than a normal environment • Patients with lowered levels of resistance due to illness • Health care personnel have frequent contact with body fluids • Nosocomial infection – contracted by 5-10% of patients while receiving health care • Results in 80,000 deaths per year
Scope of the problem • Industrial illness – a disease contracted by a health care professional during work • Blood-borne pathogens such as Hepatitis B and HIV can be transmitted through needle sticks • 800,000 needle sticks occur each year • Up to 500 health care workers die each year from Hepatitis B • Follow precautions when performing procedures • Dispose of all sharps in proper containers
Regulatory Agencies • Center for Disease Control and Prevention (CDC) - Responsible for developing safe guidelines to help prevent and control the spread of infectious diseases • Occupational Safety and Health Administration (OSHA) - Responsible for maintaining minimum health and safety standards for employees
Prevention: Medical Asepsis • Medical asepsis (clean technique): procedures to decrease the number and spread of pathogens • Hand washing, good personal hygiene, cleaning rooms between patient use, proper disposal of gloves after contact with body fluids or contaminated objects
Prevention: Surgical Asepsis • Surgical asepsis (sterile technique): procedures that completely eliminate the presence of pathogens from objects and areas • Sterile caps, gowns, masks, and gloves • Sterilizing instruments • Maintaining sterile fields • Changing dressing • Disposing of contaminated materials
Breaking chain of infection • Most important concept: breaking at least one link stops the infectious disease • Chain of infection summarized into 3 components: 1. Source of infecting microorganisms (1 & 2) 2. Means of transmission for the micro- organisms (3, 4 & 5) 3. Susceptible host (6)
Breaking chain of infectionBest defenses: 1. Decrease the sources of infecting microorganisms (1 & 2) 2. Prevent means of transmission for the micro-organisms (3, 4 & 5) 3. Maximize the resistance of the host (6)
Methods to decrease the sourceof microorganisms• Perform proper hand washing• Decontaminate surfaces and equipment with antiseptics, disinfectants and sterilization procedures• Avoid contact with patients and others when harboring infectious microorganisms
Preventing transmission ofmicroorganisms• Wear PPE – personal protective equipment: caps, gloves, gowns masks, booties and eye protection• Follow isolation procedures when indicated• Take additional precautions when working with patients who have highly contagious diseases. Don’t ignore posted signs.
Maintaining resistance • Provide and practice good hygiene • Ensure proper nutrition and fluid intake • Get enough rest • Decrease stressors – physical and psychosocial - that weaken the immune response • What can you do in your life to increase resistance to disease- causing pathogens?
Standard Precautions • Developed by the CDC • Follow at all times and apply to every patient • To prevent contact with potentially infectious body fluids: blood, secretions, excretions, non-intact skin and mucous membranes
Handwashing • Perform proper handwashing techniques: • when coming on the clinical site • when taking a break or leaving work • between client contacts • before gloving and after ungloving • before and after touching your face • after contact with any contaminants • before touching items considered clean
Handwashing Procedure – step-by-step how to do it • Explain why is it important to know (1) the procedure – what to do (2) the rationale – the reason you do it that way, why each step is important
Personal Protective Equipment • Abbreviated PPE • Includes gloves, masks, protective eyewear, gowns, caps and shoes • Use appropriate PPE in situations that could cause infection to you or your client • Use clean, non-sterile gloves when handling blood, body fluids, secretions, excretions, contaminated items, mucous membranes and non-intact skin
Gloves • Change gloves between tasks/procedures on the same client if there is contact with material that may contain a high concentration of microorganisms (ex: feces) • Remove gloves promptly after use, before touching non-contaminated items and environmental surfaces and before taking care of another patient • After removing gloves, wash your hands
Face Protection • Face protection: Mask, Eye Protection and Face Shield • Hospital workers wear a mask and eye protection or a face shield to protect mucous membranes of the eyes, nose and mouth during procedures that could involve splashes or sprays of blood, body fluids, secretions or excretions.
Gowns • Gowns may be cloth or paper • Cloth gowns are reusable • Paper gowns are disposable • Some clinical sites provide gowns to clients for physical exams • A clean, non-sterile gown protects skin and prevents soiling clothing during procedures that could involve splashes or sprays of blood, body fluids, secretions or excretions. • Follow the procedures on your clinical site(s)
Removing a Gown • Remove a soiled gown as promptly as possible • Fold front of gown into itself, outside in • Place cloth gowns in a closed receptacle marked with the biohazard symbol to be picked up, laundered and re-used • Place paper gowns in a closed waste can in a red plastic bag marked with the biohazard symbol • Wash hands promptly to avoid transferring microorganisms
Client care equipment • Handle used/soiled client care equipment to prevent skin, mucous membranes and clothing from exposure to blood, body fluids, secretions and excretions which could be transferred to other patients and environments • Reusable equipment must be properly cleaned and reprocessed before being used on another client • Discard single-use items appropriately
Environmental Control • Follow procedures for the routine care, cleaning and disinfection of environmental surfaces, beds, bedside equipment, and other frequently touched surfaces • For used linen that is soiled with blood, body fluids, secretions and excretions – fold with soiled surface in, handle to prevent exposing skin, mucous membranes and clothing which could transfer microorganisms to other environments, and place in designated biohazardous medical waste receptacle
Occupational Health andBlood-Borne Pathogens • Take care to prevent injuries when using and cleaning/disposing of “sharps” - needles, scalpels, and other sharp instruments • Place used disposable syringes, needles and scalpel blades in appropriate puncture-resistant containers • Containers should be located close by for convenient disposal • Placer reusable syringes and needles in a puncture resistant container for transport to be reprocessed (sterilized)
Occupational Health andBlood-Borne Pathogens • Never recap used needles • Follow facility policies on how to handle contaminated needles • If the facility allows recapping (for example, drawing up from a multi-dose vial), use either a one-handed “scoop” technique or a mechanical device to hold the needle sheath • Do not remove used needles from disposable syringes by hand • Do not bend, break or manipulate used needles
Occupational Health andBlood-Borne Pathogens • Use mouthpieces, resuscitation bags, or other ventilation devices as an alternative to mouth-to- mouth resuscitation methods. • Keep these devices available in areas where clients may need to be resuscitated (ie, birth rooms)
Using a flow inflatingresuscitation bag on a baby
Environmental control • Follow facility infection control procedures for cleaning the environment, jacuzzi tubs, etc. • Use Transmission-Based Precautions: • Airborne precautions • Droplet precautions • Contact precautions
Airborne Precautions • Airborne droplets or dust particles containing infectious agents can remain suspended in the air for long periods of time • Air currents can blow them long distances • Can be emitted during talking, sneezing, coughing and whispering • Examples: Mycobaterium tuberculosis, Rubeola (measles) and Varicella (chicken pox)
Droplet Precautions • Propelled short distances through the air • Deposited on host’s conjunctiva, nasal mucosa or mouth • Can be emitted during talking, sneezing, coughing and during procedures like suctioning and bronchoscopy • Examples: streptococcal pharyngitis, mumps, influenza, rubella, some some pneumonias, meningitis and sepsis
Contact Precautions • Most important and frequent mode of transmission for nosocomial infections • Nosocomial = originates/takes place in hospital or other health care facility • Nosocomial infection = the client gets it as a result of being in the health care facility • Example: herpes (HSV), impetigo, scabies, some gastrointestinal, respiratory, skin and wound infections • Direct-contact & Indirect-contact transmission
Direct Contact Indirect contact Transmission transmission• Occurs when touching • Occurs when a the infected client’s dry contaminated object skin during client care is touched. activities like giving a • For example, massage coming in contact• Can occur between two with needles, clients: a source of the instruments, infecting micro-organism environmental and a susceptible host surfaces or client care items.
Double-bagging technique • Used when disposing of medical waste from clients with infections (ex HIV) • Health care worker “A”, wearing proper PPE, takes the contaminated bag from the area • “A” slips it into another bag held by co- worker “B” • “B” does not touch the contaminated bag • “A” does not touch the clean bag • The bags are labeled according to the facility policy with hazardous waste or linen markers to alert to the need for special handling
Sterilization • Chemical agents and physical methods used to destroy or inhibit growth of pathogens • Bacteriostatic – inhibits growth • Bacteriocidal/germicidal – kills microorganisms • Antiseptics – bacteriostatic chemical agents, mild enough to use on skin: 70% isopropyl alcohol • Disinfectants – destroy most bacteria and viruses. Used for instruments that do not penetrate the skin and for cleaning the environment – floors, bathrooms, equipment
Disinfectants • Chemical disinfectants can be harmful to the skin. When using chemical disinfectants follow manufacturer’s directions for dilution and for antidoting any exposure • 10% household bleach in water meets OSHA requirements, kills HBV, HIV and TB • Soaking for 20-30 minutes in 70% isopropyl alcohol acts as a disinfectant: used for some instruments, glass thermometers • Boiling instruments in water: cover and boil in “rolling water” for 20 mins. Rarely used today.
Sterilization • Agents/methods that totally destroy all microorganisms including viruses and spores • Include chemical agents, gas, radiation, dry or moist heat under pressure • Most common method used is the autoclave, which sterilizes by steam created by a pressurized heating system • Small units used in a medical office; large units used in hospitals
Surgical Asepsis – Sterile Technique • Aseptic: free from pathogenic microorganisms • Sterile Technique: refers to a group pf principles and procedures designed to eliminate pathogens • Sterile field: an area designated as free from microorganisms • Example: a sterile towel placed on a clean, dry surface – the towel becomes the sterile field • Consider the field as a 3-dimensional area
Maintaining a sterile field • Field should be above the waist height • Do not bring contaminants into the field • Actions that contaminate the field: touching it, allowing it to become wet, reaching across it, talking or coughing directly over the surface • Work to the side of the field • Sterile gloves come in sealed packages that must be opened at the edge of the sterile field and placed onto the field.
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