infection and infectious agents causing diseases

infection infectious agents

1. INFECTION

2. Microorganisms are necessary  for normal body functions. Some organisms produce food and maintain normal planet’s ecology. The moment harmony is upset, microorganisms are capable of producing diseases. An infection occurs when a disease-causing organism enters the body and starts to multiply when they come in contact with favorable environment. An infection results when a microorganism or pathogen colonizes a host organism, using its resources to live and replicate. A disease results when there is a change or impairment of normal tissue function due to the pathogen. An infectious disease is any disease caused by the growth of pathogenic microbes in the body. It may or may not be communicable (i.e. contagious). INTRODUCTION

3. Bacteria are  present inside us, on us and around us in our environment. Resident Flora- Bacteria present inside us. Helps in digestion of food. ( Unharmful ) Transient Flora- Bacteria which we get from environment. Air, Drinking Water, food, Harmful Get Activated when meet Dust, clothes etc. favorable environment

4. Infection occurs Pathogens ( a microorganism   that causes disease Invades body Multiply Produces disease Begins Usually causing harm to the host .

5. Infection is the invasion of a host organism’s bodily tissues by disease-causing organisms, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce. Infections are caused by microorganisms such as viruses, prions, bacteria, and viroids and larger organisms like parasites and fungi. Infection is the establishment of the organisms in the tissues resulting in injury or harmful effect to the host. oInfection is the entry and development or multiplication of disease producing agents in the body of the host. DEFINITION

6. Primary infection vs. secondary infection • Primary Infection- An infection that develops in an otherwise healthy individual. Secondary Infection- An infection that develops in an individual who is already infected with a different Pathogen. Localized infection vs. systemic infection Local or Localized Infection- An infection that is restricted to a specific location or region within the body of the host. S ystemic Infection- An infection that has spread to several regions or areas in the body of the host. TYPES OF INFECTION

7. Clinical infection  vs. subclinical infection Clinical Infection- An infection with obvious observable or detectable symptoms. Subclinical Infection- An infection with few or no obvious symptoms. Opportunistic infection- An infection caused by microorganisms that are commonly found in the host’s environment. This term is often used to refer to infections caused by organisms in the normal flora. CROSS INFECTION- It is transfer of new infection from another host or external environment .

8. REINFECTION : Subsequent infection by  same organism in a host is called reinfection. FOCAL INFECTION: it is a condition where due to infection at localized sites like appendix and tonsil, general effects are produced. SUBCLINICAL INFECTION: It is one where clinical affects are not apparent .

9. Infections   may me endogenous or exogenous. ENDOGENOUS INFECTIONS • Endogenous infections are contracted from the host himself from the normal flora. • Many areas of the body have normal commensal flora. • They have many functions. • They provide barrier to the infection by competing for nutrition with pathogens. • Some produce vitamins which are useful for the host. Infections Endogenous Exogenous SOURCES OF INFECTION

10. Some produce  colicins to act against pathogens. Generally they do not cause any infections. But there are expectations. Eg .- Streptococcus mitis , Streptococcus faecalis . EXOGENOUS INFECTIONS Exogenous infections are derived from man, animals and soil. Man gets the infections from patients suffering from disease. Some person may be carries for the pathogens and they may transmit the diseases to others without getting affected .

11. ROUTES OF SPREAD  OF INFECTION There are five main routes by which a host may become infected. The respiratory route The alimentary tract The skin and mucous membrane Genital tract Placenta Routes of spread of infection Respiratory route Alimentary tract Skin and mucous membrane Genital tract Placenta

12. THE RESPIRATORY ROUTE Organisms  causing respiratory infections are as follows: Streptococcus pneumonia, Haemophilus influenzae , Mycobacterium tuberculosis, Bordetella pertusis are some of the bacterial pathogens. Common cold virus, influenza virus, adeno virus are some of the viruses producing respiratory infections. THE ALIMENTARY TRACT The intestinal diseases like cholera, bacillary dysentery, the enteric fever and bovine tuberculosis are contracted when the organisms are ingested. But in the case of entero virus infections (poliomyelitis) and Hepatitis though the organisms enter through gastro intestinal system, the effects are seen elsewhere in the body. THE SKIN AND MUCOUS MEMBRANE Organisms may be acquired from the skin as in the case of herpes virus infection or through wounds as in tetanus. Wounds may be formed from trauma or thorn pricks or needle stick injury. Organisms may also be introduced through animal bite as in the case of rabies or by insect bites as in dengue, malaria, filariasis , and yellow fever.

13. GENITAL TRACT Syphilis, gonorrhea,  hepatitis B and AIDS are some of the sexually transmitted diseases. Treponema pallidum , Neisseria gonorrhoeae , Hepatitis B virus and Human Immunodeficiency Virus are the etiologic agents respectively. PLACENTA Bacteria like T . pallidum , Viruses like rubella, cytomegalovirus, parasite like Toxoplasma gondii are some of the organisms that enter through placenta and cause disease in the newborn.

14. Redness Swelling Tenderness Warmth Drainage Red streaks leading away from Wound Development of Infection: Clinical Signs and Symptoms Local signs Inflammation Purulent exudate if bacterial infection; serous exudate if viral Tissue necrosis Lymphadenopathy Respiratory effects Systemic signs Fever , fatigue, headache, nausea Signs & Symptoms of Infection

15. THE INFECTIOUS PROCESS Chain  of infection is a process of infection that begins when an agent leave its reservoir through portal of exit & is conveyed by mode of transmission then enters through an appropriate portal of entry to infect a susceptible host. or Chain of infection is a process in which a favorable condition is required for microorganism to spread or transfer from reservoir to a susceptible host.

16. The chain  of the infection includes six components that must be in succession for any infectious disease to evolve. If one link is eliminated from the chain, then transmission of the pathogen will not occur. Infection control strategies are based on breaking the chain of infection.

17. Development of an infection occurs in a cycle that depends on the following elements: An infection agent or pathogen. A reservoir ( source for pathogen growth). A portal of exit from the reservoir. A mode of transmission. A portal of entry to a host. A susceptible host.

18. These are  any microorganism that can cause a disease such as a bacteria, virus, parasite, or fungus. Reasons that the organism will cause an infection are virulence (ability to multiply and grow), invasiveness (ability to enter tissue), and pathogenicity (ability to cause disease). Any organism is capable of causing infection if all the links/components are present. Must be able to enter the body and invade or colonize host tissue by attaching to specific host cells then cause damage to those cells by production of toxin or destructive enzymes. The pathogen may enter the body through any body orifice or broken skin. There are five types of infectious agents: Bacteria Viruses Fungi Parasites (protozoa, helminthes) Prions PATHOGENIC MICROORGANISM

19. Pathogenicity Virulence Infectious dose Toxigenicity Adaptability Ability to produce disease Disease severity Number of organisms needed  to initiate infection. Capacity to produce injurious substances that damage the host Ability to adjust to changing conditions, i.e., resistance to antimicrob ial agents. The potential for  microorganisms or parasites to cause disease depends on the following factors: a. Sufficient number of organisms b. Virulence or ability to produce disease c. Ability to enter and survive to the host d. Susceptibility of host RESERVOIR z A reservoir is where a pathogen can survive. z It is the place where the microorganism resides, thrives, and reproduces, i.e., skin of patients, carriers, inanimate objects, insects, food, water, toilet seat, elevator buttons, human feces, respiratory secretions etc. z The environment in which a pathogenic microorganism lives and survives naturally; can be human, animal, or environmental. z A reservoir is the place in the environment where infectious agents live, multiply, and reproduce so they can be transmitted to a susceptible host. A reservoir can be animate, such as people, insects, animals, and plants, or inanimate, such as water, soil, or medical devices. CHARACTERISTICS

20. PORTAL OF EXIT  FROM RESERVOIR z It is the place where the microorganism leaves the reservoir, such as the respiratory tract (nose, mouth), intestinal tract (rectum via stool), urinary tract, or blood and other body fluids. z Microorganisms can leave the body through a variety of sites such as :-  Skin and mucous membrane  Respiratory tract  Urinary tract  Gastrointestinal tract Reproductive tract Blood a. Respiratory Tract: Microorganisms leave the body of the infected person by means of droplets exhaled as a spray in coughing, sneezing, talking, or just breathing. Microorganisms also escape in nose and throat secretions. b. Gastrointestinal tract: Microorganisms that leave the body of the infected person by means of body secretions, for example, hepatitis, the virus is shed in the stool of the infected person.

21. c . Skin: Microorganisms  that leave the body of the infected person by wound drainage or through skin lesions. d. Urine: Microorganisms leave the body of the infected person by means of urine such as salmonella typhi . e. Genital tract: Microorganisms leave the body of the infected person by means of genital tract such as gonococci, treponema pallidum , HIV, VD virus.

22. MODES OF TRANSMISSION Mode  of transmission is the means by which an organism transfers from one carrier to another by either direct transmission or indirect transmission.

23. CONTACT TRANSMISSION- DIRECT  & INDIRECT Contact transmission is the most common route of transmission of organisms in health care settings. DIRECT TRANSMISSION INDIRECT TRANSMISSION CONTAMINATED ARTICLES

24. 26.  DROPLET TRANSMISSION Droplets should  come in contact with mucus membrane directly or indirectly through sneezing, coughing , talking etc.. Examples of droplet transmission include influenza, meningitis etc.

25. 27 .  AIRBORNE TRANSMISSION There are  three common diseases that are transmitted through the airborne route; chicken pox (varicella), tuberculosis, and measles. 28.  VECTOR TRANSMISSION Vector transmission  occurs when an insect or animal transmits disease to humans. e.g. Malaria and Dengue fever etc. 29.  PORTAL OF ENTRY The  opening where an infectious disease enters the host’s body such as mucus membranes, open wounds, or tubes inserted in body cavities like urinary catheters or feeding tubes.

26. SUSCEPTIBLE HOST It is  a person who is at risk for developing an infection from the disease. Factors include young people and elderly people, chronic diseases such as diabetes or asthma, conditions that weaken the immune system like HIV, certain types of medications, invasive devices like feeding tubes, and malnutrition. BREAKING OF INFECTIOUS CYCLE

27. 33.  1. CONTROL OR  ELIMINATION OF INFECTIOUS AGENT Cleaning, disinfection & sterilization of contaminated objects significantly reduce & often eliminate microorganism. It includes 4 steps- Cleaning- It is removal of all soil from object & surface.  Asepsis- It is absence of pathogenic microorganism. It is of 2 types medical & surgical asepsis.  Disinfection- It is process of killing microorganisms, spores are not involved.  Sterilization- It is process of killing microorganisms & their spores. 34.   Clean contaminated  objects (reduces the number of organisms).  Perform disinfection and sterilization (kills or inactivates organisms).  Use antiseptics to inhibit growth.  Use antiseptic agents/ antimicrobial agents.

28. 35.  2. CONTROL OR  ELIMINATION OF RESERVOIR It includes following measures-  Eliminate sources of body fluids and drainage.  Bathe with soap and water.  Change soiled dressings.  Remove standing water on bedside tables.  Cover bottles of used solutions.  Maintain patency of surgical wound drains.  Empty and rinse suction bottles.  Empty drainage bags every shift.  Place syringes and uncapped needles in moisture- resistant, puncture proof containers.  Limit contact with persons with infection or exposed to infection.

29. 36.  CONTROL OF PORTAL  EXIT 37.  Control Of Transmission   Reduce microorganisms spread.  Wash hands.  Use personal set of care items for each client.  Avoid shaking bed linens or clothes.  Discard any item that touches the floor.

30. 38.  HAND HYGIENE MOMENT 40.  CONTROL OF PORTAL  OF ENTRY Skin and mucous membranes - Maintain skin and mucous membrane integrity. Use proper hygiene measures. Clean wound sites thoroughly. Dispose of used needles in proper receptacles.  Urinary - Keep all drainage systems closed and intact.  Discard facial tissues, wound dressings, and other body excreta without touching.

31. 41.  PROTECTION OF SUSCEPTIBLE  HOST  Provide adequate nutrition.  Ensure adequate rest.  Promote body defenses against infection.  Provide immunizations.  Maintenance of hygiene.  Use of personal protective equipments like gloves, gown, Shoe cover, masks & cap.

32. 42.  COURSE OF INFECTION  BY STAGE INCUBATION PERIOD Internal between entrance of pathogen into body and appearance of first symptoms. E.g., Chickenpox 2-3 weeks. Common cold 1-2 days Mumps 18 days Course of infection by stage Incubatio n period Prodrom al stage Illness stage Convalescence

33. 43.  PRODROMAL STAGE Interval from  onset of non-specific signs and symptoms (malaise, low- grade fever, fatigue) to more specific symptoms. During this time, microorganisms grow and multiply and patient is more capable of spreading disease to others. ILLNESS STAGE Interval when patient manifests signs and symptoms specific to a particular disease. E.g., Common cold- Sore throat. Rhinitis - Sinus congestion. Mumps - earache, high fever, parotid and salivary gland swelling. The severity of patient’s illness depends on the extent of infection, the pathogenicity of the microorganisms and susceptibility of individuals. CONVALESCENCE Interval when acute symptoms of infection disappear until the individual regain his normal health. Length of recovery depends on severity of infection and patient’s general health status. Recovery may take several days to months.

34. 44.  DEFENSES AGAINST INFECTION The  body incorporates certain defenses against the invasion of pathogens causing infection. 1. SKIN : The skin is the first line of defense since most pathogens cannot enter unbroken skin. Defenses against infection Skin Phagocyte Normal body flora Immune substances Lymphatic system Factors which lesson body defenses 45.  2. PHAGOCYTE :  Another line of defense is phagocyte cells such as white blood cells. These cells engulf pathogens and absorb them. Phagocytes increase in numbers at the site of infection. 3. NORMAL BODY FLORA : Normal body flora that reside inside and outside of the body protect a person from several pathogens. 4. IMMUNE SUBSTANCES : Still another line of defense is the development by the body of antibodies and antitoxins. Because pathogens are foreign substances, the body reacts and destroys them by producing immune bodies. All patients vulnerable to cross infection or infectious diseases, particularly tetanus, should receive indicated prophylactic doses of antibiotics and immunizing agents. 5. LYMPHATIC SYSTEM : The lymphatic system also defends the body against invading pathogens. The lymph acts like a washing machine for the body. It cleanses the body tissues. Lymph flows into the tubules and glands that act as filters and strains the invaders. 6. FACTORS WHICH LESSON BODY DEFENSES : Several factors that may be present in combat casualties tend to lessen to lessen body defenses. They include wound injuries, chilling, exposure, fatigue, and malnutrition.

35. 46.  ASEPSIS Asepsis means absence  of disease producing organisms. The microorganisms of different types are present everywhere in our environment and in the human body. The purpose of medical asepsis is to prevent by all means of cross-infections from one patient to another, including communicable disease infections. The purpose of surgical asepsis is to prevent by all means of infections of the wounds of surgical patients, infection of the uterus during and after delivery, and infection that could be introduced by invasive procedures such as catheterization, injections and infusions. Asepsis Medical asepsis Surgical asepsis

36. 47.  MEDICAL ASEPSIS This includes  : 1. General cleanliness. 2. Isolation of infected persons. 3. Disinfection of all articles that may be contaminated, or used for more than one patient. 4. Correct and frequent hand-washing by all those caring for patients. SURGICAL ASEPSIS This means keeping objects and areas ‘sterile’ free from all organisms. Surgical asepsis (Sterile technique) is used in the operating room, delivery room, in doing surgical dressings and many other invasive procedures. The nurse must thoroughly understand the principle of surgical asepsis. She must be reliable in always keeping to these principles. She must know about the use and care of the masks, gloves, and gowns, the proper technique of hand washing for surgical procedures and the sterilizing and handling of sterile equipments .

37. 48.  HOSPITAL INFECTION OR  NOSOCOMIAL INFECTION Nosocomial infections are infections that are acquired by a patient due to delivery of health care services. The majority of HAI (human acquired infection) become evident 48 hours or more following admission. However, it may not become clinically evident until after discharge. There are various reasons why patients in hospital acquire infection. Patient with infectious diseases are frequently admitted to hospital. Some of these patients are able to spread their organisms to other patients and they provide one source of infection in hospital patients admitted for other causes. EXAMPLES of such infections spreading in hospital include : Salmonellosis, group A streptococcal infections, tuberculosis, viral hepatitis and other infections. When such patients require admission to hospital, the risk has to be assessed for other patients and appropriate measures taken to contain the infection with isolation procedures of varying degrees of strictness depending on the infection.

38. 49.  The commonest forms  of hospital-acquired infection are due to invasive procedures carried out on patients such as surgical operations intravenous therapy, intubation and catheterization. A variety of measures is needed to control such infections. Most nosocomial infections are transmitted by health care workers. IATROGENIC INFECTIONS Iatrogenic infections are a type of nosocomial infection resulting from a diagnostic or therapeutic procedure. (e.g.) urinary tract infection that develops after catheter insertion. Nosocomial infections may be exogenous infection or endogenous infection.

39. 50.  SITES AND CAUSES  FOR NOSOCOMIAL INFECTION URINARY TRACT 1. Insertion of urinary catheter. 2. Improper hand washing technique. 3. Contaminated catheter, tube and bag. 4. Failure to use aseptic techniques. 5. Reflux of urine from bag to bladder. Sites for nosocomial infection Urinary tract Respiratory tract Alimentary tract Surgical wounds Blood stream

40. 51.  RESPIRATORY TRACT 1. Aspiration  in unconscious patient. 2. Contaminated ET tubes. 3. Contaminated instruments. 4. Contaminated catheters. 5. Failure to use aseptic techniques. ALIMENTARY TRACT 1. Improper hand washing technique in food handlers. 2. Improper hand washing technique during tube feeding. 3. Contaminated food. 4. Contaminated water. 5. Contaminated milk. 6. Contaminated NG tubes. 7. Carriers of infection. SURGICAL WOUNDS 1. Improper hand washing technique. 2. Improper skin preparation. 3. Improper sterilization of instruments and dressing materials. 4. Failure to use aseptic techniques.

41. 52.  BLOOD STREAM 1. Contaminated  intravenous fluids, tubing or needles. 2. Improper care of needles, insertion site. 3. Improper hand washing technique. RISK FACTORS FOR HOSPITAL INFECTION 1. Broken skin or mucous membrane. 2. Obstructed urine outflow. 3. Decreased mobility. 4. Reduce haemoglobin level. 5. Neonates. 6. Aged patients. 7. Impaired defense mechanism. 8. Major invasive procedures. 9. Obesity. 10. Malnutrition. 11. Steroid therapy. 12. Immunocompromised individual. 13. Presence of remote infection 14. Use of unsterile instruments.

42. 53.  PREVENTION OF HOSPITAL  INFECTION 1. Proper hand washing technique. 2. Proper sterilization of instruments and dressing materials. 3. Proper care of needle, insertion site. 4. Isolation of patients having communicable diseases. 5. Careful and appropriate use of instruments. 6. Proper disinfection of excreta and infected material. 7. Proper and regular surveillance of infection. 8. Good housekeeping. 9. General hygiene. 10.Exclusion of carriers. 11. Use of vaccines. 54.  Infection Prevention Guidelines The  CDC guidelines for infection control and isolation precautions are used in hospital and health-care agency policies. CDC and agency guidelines are continuously updated and should be followed for your protection, as well as your patients’. Current CDC guidelines for isolation precautions in hospitals include two tiers of precautions: standard precautions and transmission-based precautions (Table 7.2). Standard Precautions Standard precautions are used in the care of all patients. These precautions require you to assume that all patients are infectious regardless of their diagnosis. Standard precautions apply to blood, secretions, excretions, open skin, mucous membranes, and all body fluids, excluding sweat. All patients with draining wounds or secretions of body fluids are considered infectious until an infection is confirmed or ruled out. Using gloves, gowns, masks, goggles, face shields, and, most important, hand washing helps prevent the spread of infection to health-care workers and other patients. Transmission-Based Precautions Transmission-based precautions are used for patients with specific communicable diseases that can be transmitted to others. Transmission-based precautions are an additional layer of protection used in addition to standard precautions. 55.  Prevention of Respiratory  Tract Infections Nosocomial pneumonia has been linked with the highest infection mortality rate in hospitalized patients. Patients who are at highest risk for pneumonia are those with endotracheal, nasotracheal , or tracheostomy tubes because these invasive tubes bypass the normal defenses of the upper respiratory tract. Strategies to prevent infections such as ventilator- associated pneumonia (VAP) are being “bundled” together to get health-care workers to remember to use these strategies. Prevention of Genitourinary Tract Infections The most common hospital-acquired infection is a urinary tract infection. Patients with urinary catheters are at the greatest risk. The urinary tract is normally a sterile tract, but insertion of a catheter into the bladder may allow organisms to enter. Institutional policy on appropriate use of urinary catheters differs, and you should follow the policy of your particular institution. Appropriate uses of catheters include use in patients with urinary obstructions, neurogenic bladder conditions, and in those in shock.

43. 56.  Indwelling urinary catheters  should be removed as soon as possible. For patients requiring long-term use of urinary catheters, intermittent catheterization is preferred because it has been shown to significantly reduce the risk of infection. Using strict aseptic technique while inserting and caring for the catheter in the health-care agency is imperative. The catheter tubing must be securely anchored to the patient’s leg, according to agency protocol, so it does not move in and out of the urethra. Movement can encourage organisms to enter the urinary tract. The closed urinary drainage system seal should never be opened. If intermittent irrigation is ordered, sterile technique must be used to protect both ends from contamination. The drainage bag should be positioned so that it is never higher than the level of the bladder to prevent backflow of urine into the bladder, which could contaminate the sterile urinary tract. If an indwelling urinary catheter and drainage system is used long term, the catheter and the entire system should be changed regularly using sterile technique. Standards in home care differ from institutional care because patients are generally at lower risk of infection within their own environment. 57.  All long-term indwelling  urinary catheters are considered colonized, but only a few will cause infection in the patient. Remember that the most crucial point at which bacteria may enter the patient is during the insertion of the catheter, so excellent technique is required. Another point to remember is that the urinary tract is highly vascular (many blood vessels close to the surface), so that an infection in this tract can easily result in bacteremia (bacteria in the blood), which can then progress to septicemia (infection in the blood), a potentially life- threatening condition. Prevention of Surgical Wound Infections The initial dressing for surgical wounds is applied in the operating room using sterile aseptic technique. Postoperative orders indicate when to change the dressing. Sterile technique should be used. The wound is monitored with every dressing change for signs of infection. 58.  Protection from Septicemia  (Sepsis) Septicemia (commonly called blood poisoning) is a blood infection with a variety of causes, including infection in another body site and contamination of invasive catheters and solutions (central lines, arterial lines, pulmonary artery catheters, urinary catheters). Insertion and care of these catheters require sterile technique and careful observation for infection signs. All solutions should be examined for expiration date, signs of contamination, cloudiness, particles, or discoloration before use. Indications of sepsis such as fever, tachypnea, tachycardia, hypotension, and elevated white blood cell count should be reported promptly to the physician for immediate treatment. Blood cultures may be ordered. Antibiotics are used to treat sepsis. An intravenous (IV) drug, drotrecogin alfa (activated) ( Xigris ), is available to treat severe sepsis when death is likely. Drotrecogin alfa (activated) is given for 96 hours. It is associated with a risk of bleeding. Drotrecogin alfa (activated) has reduced mortality in patients, which may be due to its anti inflammatory effects.

44. 61.  Guidelines to Prevent  Spread of Infection to the Patient, Self, and Family • Bathe daily and wear a clean uniform/clothing every day. • Keep your fingernails short and do not wear acrylic nails. Both long nails and acrylic nails have been associated with spread of infection to patients and they can be colonized with harmful bacteria. Multiple studies have demonstrated that long fingernails and artificial nails harbor bacteria and have caused infections in patients that sometimes have resulted in death. • Avoid wearing rings and bracelets that harbor organisms. • Cleanse your stethoscope at least daily and in between patient use with alcohol. VRE bacteria have been cultured from stethoscopes in a hospital setting.

45. 62.  • Wash your  hands between each patient contact. Hand washing is recognized as the single most important action to take to prevent spread of infection. If you are unable to use soap and water, use a nondrying alcohol hand gel, which has been shown to be effective in cleansing hands and preventing drying of the skin. • Follow prescribed isolation precautions for your protection, as well as that of the patient. • Remove your uniform and bathe/shower when you come home from work. This will decrease the spread of antibiotic-resistant bacteria to your home and your family. Keep your nursing shoes clean and put away from the rest of the family.

46. 63.  Prevention of infection  in healthcare settings " The Centers for Disease Control and Prevention (CDC) recommends two tiers in the prevention of infection within healthcare settings. The first tier includes universal precautions and other standard precautions. Both are intended to reduce the risk of transmission of bloodborne viruses and other common organisms found within healthcare settings, and therefore should be utilized at all times. The second tier is the use of isolation, or transmission-based precautions, which will be described later. These are implemented only when more pathogenic organisms are of concern. (Examples of organisms and the precautions that should be taken are found in Appendix 1.)

47. 64.  Universal precautions The CDC  adopted the term universal precautions and devised the recommendations in 1987, largely in response to the HIV epidemic. The recommendations state that blood and body fluid precautions should be implemented consistently for all patients regardless of their blood borne infection status, as this would not always be known. All healthcare workers, staff, patients, and visitors are encouraged to undertake universal precautions at all times. In addition, these measures can also help to minimize cross infection of other organisms. (A list of body fluids to which universal precautions apply can be found in Appendix 2.)

48. 65.  Precautions Universal precautions measures  include the following: 1. Gloves, which should be well-fitting and available for use wherever contact with blood or body fluids is anticipated. Although gloves cannot prevent penetrating injuries from sharp instruments and equipment, they can reduce the incidence of hand contamination from blood and body fluids. In addition, any broken skin on the hands of health staff – for example, cuts – should be covered, ideally with an effective barrier that is both waterproof and breathable. Gloves should be changed immediately if contamination with blood or body fluids occurs, or if they are no longer intact. They should also be changed between patients. If gloves are not changed under these circumstances the risk of exposure to blood borne viruses is greatly increased, as is the risk of cross infection. Gloves should ideally be single use and be made of latex or vinyl, depending on the task (latex substitutes such as nitrile may be used if latex allergies are of concern). Sterile surgical gloves, which fit more tightly than ordinary latex gloves, should also be available for procedures involving sterile areas of the body.

49. 66.  Ideally these gloves  should not be washed or disinfected as these can cause deterioration or disintegration, causing holes which may not be visible. (Disinfecting used gloves in circumstances where single use is not feasible will be discussed later under decontamination). 2.Mucous membranes of healthcare workers (for example, eyes and mouth) should be protected from blood or body fluid splashes. Glasses, visors or shields can be used for the eyes and should be available for use, especially during procedures with increased risk of splashes, for example, surgical procedures, intravenous line insertions, irrigation, airway suctioning or bronchoscopy. Masks should also be worn during any procedures with an increased risk of splashes. Masks must be changed if they become contaminated or if they are not intact. Decontamination of reusable visors should be carried out frequently. 3. Protective clothing (for example, impermeable plastic aprons or gowns) should be worn where there is a risk of blood or other body fluids splashing onto clothing or bare skin.

50. 67.  4. Proper handling  of contaminated instruments • Needles, blades, scalpels, intravenous devices, and other sharp instruments should be handled with care in order to avoid inoculation injuries or contamination onto mucous membranes. • Care should be taken during the use, cleaning and on disposal of sharp instruments. • Needles should never be recapped with their covers, never be removed from the syringes, and never be bent or broken by hand. If needles have to be recapped, recapping should be done using a one handed scoop technique or by using a mechanical device. • The number of sharp instruments should be kept to a minimum during procedures, and should always be kept in sight. • After use, all single use sharps should be placed in puncture resistant containers such as sharps boxes. These containers should be marked as sharps boxes, be made of a puncture-proof material, and have a lid that cannot be removed and which can be sealed tightly. Containers should be kept close to where sharps are used, ensuring minimal handling of contaminated objects and safe and quick disposal of them. Hands should never be put inside a container, nor should any items in the container be retrieved from it.

51. 68.  The containers should  be changed whenever they become two thirds full, or if they become contaminated on the outside, to avoid potential inoculation injuries or contamination on disposal. • Disposal of all sharp instruments should be by incineration. The above measures will help to limit the potential exposures of healthcare workers to blood borne pathogens. 5. Handling and disposal of linen Linen contaminated with blood or body fluids should be handled carefully. The use of protective clothing is advised. Contaminated linen (for example, bed sheets, pajamas, and towels) is usually described as infected or soiled. Such linen should be disposed of immediately, normally into a watersoluble bag, and clearly identified as contaminated. Identification of contaminated linen can be made by using a bag of an agreed-upon colour , or labelling the bag clearly. If no bags are available and a non-disposable bucket is used, the bucket must also be clearly marked and must be disinfected frequently. Clear identification will inform all other staff that precautions should be taken when handling the bag or the linen inside it. If the soiled objects are not to be decontaminated immediately, the bags should be stored safely where they can be easily recognized.

52. 69.  To decontaminate linen,  it should be washed at a high temperature (at least 70° C), or on a heat disinfection cycle. Water-soluble bags are useful, as they allow staff to avoid handling the contaminated linen. A temperature of 70° C will kill most common organisms and will also facilitate the dilution of the particles in the water. If a temperature of 70° C is not possible, thorough washing, rinsing and drying, at lower temperatures (preferably using a disinfectant) should be carried out. Minimal handling of body fluids or moist body substances while washing is essential. Disinfectants will be discussed under decontamination. 6. Proper handling of clinical wastes Clinical waste includes any materials generated from patient care. This includes waste that could potentially transmit microorganisms. Such clinical waste can include soiled dressings, cotton swabs, and catheter bags. Disposal of clinical waste, including waste contaminated with blood or body fluids, should be carried out immediately, with the wastes put into clearly marked bags. Gloves and protective clothing should always be used when handling clinical waste. If bags are not available and non-disposable buckets are used, the buckets must be disinfected frequently, as they could be a source of infectious material. Bags or buckets should have a covering lid, and should be kept close to where contaminated waste will be generated.

53. 70.  Bags and buckets  should never be overfilled and should be closed securely as soon as they are full. They should be sent for incineration, and stored until they are out of the healthcare setting. If incineration is not possible, burial should be in deep holes to avoid animal scavenging or exposure to the public. 7. Cleaning of spillages of blood and body fluids Spillages of blood and potentially infected body fluids onto the floor, on equipment, or other surfaces must be cleaned as soon as they occur, in order to prevent further unnecessary exposure. It is important for health staff to wear gloves and other protective clothing during cleanup. Spillage kits are often available in healthcare settings; if not, the preferred method for cleaning spillages is disinfection granules (for example, hypochlorite) sprinkled onto the spillage and left for a few minutes, before being cleaned up with disposal cloths and disposed of into a clinical waste bag. The area should then be cleaned. Cleaning and disinfectants will be discussed later. If no disinfection granules are available, disposable paper towels or rags should be placed on the spillage to absorb it, to prevent its spreading, and to make it easier to remove. Again, hands must be gloved when cleaning up spills of infected waste.