1. Infection Control Dr. Belal M. Hijji, RN, PhD February 18, 2012

2. Learning Outcomes After this lecture, students will be able to: –Define key terms –Recognise the elements of the infection chain –Identify the body’s normal defences against infection. –Explain conditions that could promote development of nosocomial infections. –Describe strategies for standard precautions. –Identify principles of surgical asepsis. –Describe nursing interventions designed to control and prevent infection. 2

3. Definition of Key Terms Infection: Is the invasion of a susceptible host by pathogens or microorganisms resulting in disease, whereby normal tissue function is altered. Colonisation: Is the presence, growth, and/ or multiplication of a microorganism in the body without causing disease or infection. Communicable disease: Refers to an infectious disease that can be transmitted directly from one person to another. 3

4. Chain of Infection Development of an infection depends on the presence of six elements (Slide 5). These are:Slide 5 –Infectious agent: In sufficient number, virulence, and ability to enter and survive in a susceptible host. –Reservoir: A place where microorganisms can survive, multiply, and await transfer to a susceptible host. –Portal of exit: Microorganisms must find a portal of exit out of a reservoir such as skin, mucous membranes, respiratory tract, GIT, reproductive tract, and blood. –Mode of transmission: The importance of this element is that it can be interrupted by practising infection prevention and control techniques. –Portal of entry: These are the same routes that microorganisms use to exit. –Susceptible host: This is an individual who has a low degree of resistance to pathogens. His natural defences against infection are weak and has certain risk factors (age, drugs, immunisation). 4

5. 5

6. Defences Against Infection Normal flora: These do not cause disease and help to maintain health. They can inhibit multiplication of microorganisms landing on the skin. Body system defences: These are: –Skin: Provides mechanical barrier to pathogens –Mouth: As above, and saliva contains microbial inhibitors and washes away particles containing microorganisms –Respiratory tract: Contains cilia lining upper airways and macrophages that trap inhaled microbes and sweep them outward to be expectorated or swallowed, and engulf and destroy microorganisms –Urinary tract: Washes away, and provides barrier to, microorganism –GIT: Destroys microorganisms incapable of surviving low pH, and prevents retention of bacterial contents –Vagina: Acidic secretions inhibit growth of many microorganisms 6

7. Inflammation: Is the body’s cellular response to injury or infection. Inflammation is a protective vascular reaction that delivers fluid, blood products, and nutrients to interstitial tissues in an area of injury. This process neutralises and removes pathogens. Signs of local inflammation include swelling, redness, heat, pain or tenderness, and loss of function of the affected part. Signs and symptoms of systemic inflammation may include fever, high WBCs, malaise, anorexia, nausea, vomiting, and lymph node enlargement Immune response: When a foreign material enters the body, a series of responses changes the body’s biological makeup. Upon next entry, the antigen is either neutralised, destroyed, or removed. 7

8. Nosocomial Infection Is an infection that was not present or incubating at the time of admission to a health care setting. Clients in these settings, who often have multiple illnesses and are poorly nourished older adults, are at a higher risk for infection than those at home. They have a lowered resistance to microorganisms because of underlying medical conditions (HIV, DM, or cancer). In addition, invasive diagnostic examinations and treatment with broad-spectrum antibiotics increase the risk for certain infections. Is exogenous: Arises from microorganisms outside the individual such as Salmonella and Clostridium tetani. Or, Endogenous: Occurs when part of the client’s flora becomes altered and an overgrowth results. This often happens when the client receives broad-spectrum antibiotics. 8

9. Standard Precautions 9

10. Principles of Surgical Asepsis Bear in mind that failure to adhere to any principle of surgical asepsis endangers clients and increases the risk for infection. Those principles are: A sterile object remains sterile only when touched by another sterile object Only sterile objects may be placed on a sterile field. A sterile object or field out of the range of vision or an object held below a person’s waist is contaminated. A sterile object or field becomes contaminated by prolonged exposure to air. A sterile object or field becomes contaminated by capillary action when a sterile surface comes in contact with a wet contaminated surface 10

11. Because fluid flows in the direction of gravity, a sterile object becomes contaminated if gravity causes a contaminated liquid to flow over the object’s surface. The edges of a sterile field or container are contaminated. 11

12. Nursing Interventions for Infection Control And Prevention As a health promotion issue, infection control begins with prevention. Review with clients and their families the following preventive measures: –Nutrition: Influences resistance to infection. Proper diet promotes optimal immune functioning and is comprised of the four food groups. –Personal hygiene: Aims at reducing the microbial load of the skin and maintaining the well-being of mucous membranes. –Immunisation: This provides immunity to clients and decreases the occurrence of many vaccine-preventable diseases like diphtheria and measles. –Rest and exercise: Physical exercise increases lung capacity, circulation, energy, and endurance. It decreases stress and improves appetite, sleeping and elimination. 12

13. Control and Elimination of Infectious Agents Cleaning: This involves the removal of foreign material from objects. Cleaning must be occur before disinfection and sterilisation procedures. Disinfection and sterilisation: Physical and chemical processes are used to disrupt the internal functioning of microorganisms. Control or Elimination of Reservoirs This is achieved through eliminating sources of body fluids, drainage, or solutions that might harbor microorganisms. 13

14. Control of Portals of Exit Avoid talking, sneezing, or coughing directly over a surgical wound or sterile dressing field. Avoid working with clients who are highly susceptible to infection if you have cold or communicable infection. Control of Transmission Hand washing: The most important and most basic technique in the prevention and control of transmission of pathogens. Isolation: Refers to using gloves, masks, eyewear, and gowns. Standard precautions: 14