1 Nature of infection.pptx

Nature of infection
- Terminologies
- Infectious Agents
-Types of infection
-MRSA
-Stages of Infection
-Nosocomial Infection
- Factors affecting risk of infection
-Mechanism of Transmission
-Programme

1. DR.MRS .BHAVANI.A., M.Sc. (NSG), PhD NURSING TUTOR RANI MEYYAMMAI COLLEGE OF NURSING, ANNAMALAI UNIVERSITY INFECTION CONTROL Nature Of Infection 1

2. Terminology Infection: an infection is the invasion of a susceptible host by pathogens or microorganisms, resulting in disease. Pathogens: a bacterium, virus, or other microorganism that can cause disease. Dr.T.V.Rao MD 2

3. INTRODUCTION A major concern for health practioners is the danger of spreading microorganisms from person to person and from place to place. Microorganisms are naturally present in almost all environments . Some are beneficial; some are not. Some are harmless to most people, and others are harmful to many people. Still others are harmless except in certain circumstances. Prevention of infection is a major focus for nurses. As primary caregivers, nurses are involved in identifying, preventing, controlling, and teaching the patient about infection. 3

4. INFECTION The word "infection" means something different from "disease," although the two terms sometimes are confused. Disease is a general word that describes any abnormality of the human condition or something that interferes with the normal, healthy functioning of the body. 4

5. Cont… Diseases include infections and infestations, among others. Infection is a term that refers specifically to any abnormal condition caused by a microbe, such as a bacterium, virus, or parasite, that has invaded another organism (like a human) and interfered with some aspect of its function. An infestation is similar to an infection. It refers to any abnormal condition caused by an organism larger than a microbe, such as an insect, louse, or worm. 5

6. Cont… The phrase "infectious diseases" is used to refer to both infections and infestations, regardless of the severity of the condition. An infection beneath a fingernail and a serious case of hepatitis C both are considered infectious diseases. Some infectious diseases can be passed from person to person. Some are transmitted by insects or other animals. And you may get others by consuming contaminated food or water or being exposed to organisms in the environment. Signs and symptoms vary depending on the organism causing the infection, but often include fever and fatigue. Mild infections may respond to rest and home remedies, while some life-threatening infections may need hospitalization. 6

7. Contd …. Many infectious diseases, such as measles and chickenpox, can be prevented by vaccines. Frequent and thorough hand-washing also helps protect you from most infectious diseases. Its important to know the difference between infection and colonization. Colonization is presence and growth of microorganism within host but without tissue invasion or damage. Disease or infection results only if the pathogens multiply and alter normal tissue function Dr.T.V.Rao MD 7

8. Contd …. If the infectious disease can be transmitted directly from one person to another, it is termed as communicable disease . If the pathogens multiply and cause clinical signs and symptoms, the infection is symptomatic. if clinical signs and symptoms are not present, the illness is termed as asymptomatic. Ex. Hepatitis C is communicable that are asymptomatic. Dr.T.V.Rao MD 8

9. Cont… The hallmark of many infections is inflammation, which is largely a result of the immune system's response to infection, irritation, or injury. The characteristics of inflammation include redness, warmth, swelling, and pain. 9

10. Cont… Important players in the immune reaction are the white blood cells. In response to germs, white cells race to the area of infection to fight off the invader; the word "pus" refers to a thick fluid produced by the body in response to an infection that contains these white cells along with other substances resulting from the reaction. Bacteria that cause pus are called pyogenic. 10

11. Chronic infections Chronic infections are those infections that last a longer time—weeks, months, or even years. A chronic infection can develop from an acute infection that does not clear up. Some chronic infections continue to have signs and symptoms, causing discomfort and interfering with life for long periods of time. Other chronic infections may have few or no signs. People who have a chronic infection may not be aware that they still have an active infection and may still be capable of passing the infectious microbe to others. 11

12. The nature of infections Micro-organisms - bacteria, fungi, viruses, protozoa and worms Most are harmless [non-pathogenic] Pathogenic organisms can cause infection Infection exists when pathogenic organisms enter the body, reproduce and cause disease 12

13. INFECTIOUS AGENT  Some of the more prevalent agents that cause infection are bacteria, viruses, and fungi. Bacteria, the most significant and most commonly observed infection- causing agents in healthcare institutions, can be categorized in various ways. They are categorized by shape as spherical, rod shaped, or corkscrew shaped. Bacteria can be categorized as either gram positive or gram negative, based on their reaction to the Gram stain. 13

14. Cont… For example, gram-positive bacteria have a thick cell wall that resists decolorization and are stained violet. However, gram-negative bacteria have chemically more complex cell walls and can be decolorized by alcohol. A virus is the smallest of all microorganisms, visible only with an electron microscope. Many infections are caused by viruses 14

15. Cont… including the common cold and the deadly disease acquired immunodeficiency syndrome. Antibiotics have no effect on viruses; however, there are some antiviral medications available that seem to be effective with some viral infections. When given in the prodromal stage of certain viruses, these medications can shorten the full stage of the illness. 15

16. Cont… Fungi, plant like organisms that also can cause infection, are present in the air, soil, and water. Some examples of infections caused by fungi include athlete’s foot, ring worm, and yeast infections. These infections are treated with antifungal medications; however, many infections due to fungi are resistant to treatment. 16

17. Cont… Not all organisms to which a person is exposed cause disease. An organism’s potential to produce disease in a person depends on a variety of factors, including: Number of organisms Virulence of the organism, or its ability to cause disease Competence of the person’s immune system. Length and intimacy of the contact between the person and the microorganism. 17

18. Microorganisms on the skin are called resident (or) Transient flora. Resident Means: Residents organisms are considered permanent resident of the skin. Resident organisms are not easily removed Transient flora: Transient Microorganisms attach to the skin when a person has content with another person Cont…

19. patient's own flora (skin microbiota ) cross infection from medical personnel cross infection from patient to patient hospital environment- inanimate objects - air - dust - IV fluids & catheters - washbowls - bedpans - endoscopes - ventilators & respiratory equipment - water, disinfectants etc Where do the microbes come from?

20. Theory of Infection Control Microorganisms Bacteria Fungi Viruses Protozoa

21. Pathogenic Disease causing Infectious agent Causes disease in healthy person Opportunistic pathogen Causes disease in susceptible person Virulence Communicable diseases

22. Non-pathogenic Resident flora Colonization Can cause disease if transmitted to other areas 22

23. Types of Infection Local Specific area of body is infected Systemic Microorganisms spread & damage other body areas Bacteremia when microbes enter blood stream Septicemia – when bacteremia spreads through all of the body systems Acute vs. chronic infection

24. Nosocomial – infections that occur as a result of health care delivery Endogenous source Exogenous sources Iatrogenic – is a type of nosocomial infection directly caused by any diagnostic or therapeutic source

25. Contd …. Drug-Resistant Pathogens MRSA VRE ( Vancomycin resistant enterococcus) MDR TB (Multi-drug resistant TB)

26. MRSA Discovered in 1981 Found on skin and in the nose of 1 in 3 healthy people - symptomless carriers Widespread in hospitals and community Resistant to most antibiotics When fatal - often due to septicaemia 26

27. STAGES OF INFECTION   An understanding of the stages in the development of an infection is necessary to intervene and disrupt the infection cycle. An infection progresses through the following phases: Incubation period Prodromal stage Full stage of illness Period of decline and Convalescent period 27

28. Incubation Period The incubation period is the interval between the pathogen’s invasion of the body and the appearance of symptoms of infection. During this stage, the organisms are growing and multiplying. The length of incubation may vary.   28

29. Prodromal Stage A person is most infectious during the prodromal stage. Early signs and symptoms of disease are present, but these are often vague and nonspecific, ranging from fatigue and malaise to a low –grade fever. This period lasts from several hours to several days. During this phase, the patient often does not realize that he or she is contagious. As a result, the infection spreads. 29

30. Full Stage of Illness The presence of specific signs and symptoms indicates the full stage of illness. The type of infection determines the length of the illness and the severity of the manifestations. Symptoms that are limited or occur in only one body area are referred to as localized symptoms, whereas symptoms manifested throughout the entire body are referred to as systemic symptoms. 30

31. Period of decline This is the stage during which the number of pathogen particles begins to decrease, and the signs and symptoms of illness begin to decline. However, during the decline period, patients may become susceptible to developing secondary infections because their immune systems have been weakened by the primary infection. Dr.T.V.Rao MD 31

32. Convalescent Period The convalescent period is the recovery period from the infection. Convalescence may vary according to the severity of the infection and the patient’s general condition. The signs and symptoms disappear, and the person returns to healthy state. However, depending on the type of infection, the person may have a temporary or permanent change to his or her previous health state even after the convalescent period. 32

33. What is Nosocomial Infection Any infection that is not present or incubating at the time the patient is admitted to the hospital 33

34. FACTORS AFFECTING THE RISK FOR INFECTION Integrity of skin and mucous membranes, which protect the body against microbial invasion. pH levels of the gastrointestinal and genitourinary tracts, as well as the skin, which help to ward off microbial invasion. Integrity and number of the body’s white blood cells, which provide resistance to certain pathogens. Age, sex, race, and hereditary factors, which influence susceptibility. Neonates and older adults appear to be more vulnerable to infection. 34

35. Cont… Immunizations, natural or acquired, which act to resist infection. Level of fatigue, nutritional and general health status, the presence of preexisting illnesses, previous or current treatments, and certain medications, which play a part in the susceptibility of a potential host. Stress level; stress may adversely affect the body’s normal defense mechanisms. Use of invasive or indwelling medical devices, which provide exposure to and entry for more potential sources of disease producing organisms, particularly in a patient whose defenses are already weakened by disease. 35

36. Florence Nightingale, 1820 - 1907

37. The very first requirement in a hospital is that it should do the sick no harm

38. MECHANISMS OF TRANSMISSION Contact : direct (person-person), indirect (transmission through an intermediate object-- contaminated instruments Cross transmission Airborne : organisms that have a true airborne phase as pattern of dissemination (TB, Varicella ) Common-vehicle : common animate vehicle as agent of transmission (ingested food or water, blood products, IV fluids) Droplet : brief passage through the air when the source and patient are in close proximity

39. Modes of spread Two sources of infection: Endogenous or self-infection - organisms which are harmless in one site can be pathogenic when transferred to another site e.g., E. coli Exogenous or cross-infection - organisms transmitted from another source e.g., nurse, doctor, other patient, environment (Peto, 1998) 39

40. Spread - entry and exit routes 40 Natural orifices - mouth, nose, ear, eye, urethra, vagina, rectum Artificial orifices - such as tracheostomy, ileostomy, colostomy Mucous membranes - which line most natural and artificial orifices Skin breaks - either as a result of accidental damage or deliberate inoculation/incision

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42. Components of Infection Control Programme The important components of the infection control programme are: Basic measures for infection control, i.e. standard and additional precautions; · education and training of health care workers; · protection of health care workers, e.g. immunization; identification of hazards and minimizing risks; · routine practices essential to infection control such as aseptic techniques, use of single use devices, reprocessing of instruments and equipment, antibiotic usage, management of blood/body fluid exposure, handling and use of blood and blood products, sound management of medical waste; 42

43. Need For Control programme? Effective work practices and procedures, such as environmental management practices including management of hospital/clinical waste, support services (e.g., food, linen), use of therapeutic devices; surveillance; · incident monitoring; outbreak investigation; infection control in specific situations; and research . 43

44. Developing Infection Control Programme Every infection control program should develop a well-defined written plan outlining the organizational philosophy regarding infection prevention and control. The plan should take into account the goals, mission statement, and an assessment of the infection control program. It should include a statement of authority, and should review patient demographics including geographic locations of patients served by the healthcare system 44

45. Aims of Infection Control To review and approve a yearly programme of activity for surveillance and prevention; to review epidemiological surveillance data and identify areas for intervention; to assess and promote improved practice at all levels of the health facility; to ensure appropriate staff training in infection control and safety management, provision of safety materials such as personal protective equipment and products; and training of health workers. 45

46. GUIDELINES for Effective Control of Infections Hand washing and Hospital Environmental Control * Immunization * Infectious Diseases Control * Intravascular Device-Related Infections and its control * Isolation Precautions * Long-Term Care Facilities 46

47. GUIDELINES for Effective Control of Infections Guidelines for Infection Control in Health Care Personnel Surgical Site Infections Control Urinary Tract and Respiratory Tract Infections Control Ordering and Preparing Guidelines appropriately Home care Hospital Construction Sterilization / Disinfection 47

48. Responsibilities of the Infection Control Program Surveillance of nosocomial infections Outbreak investigation Develop written policies for isolation of patients Develop written policies to reduce risk from patient care practices Cooperation with occupational health Education of hospital staff on infection control Ongoing review of all aseptic, isolation and sanitation techniques Eliminate wasteful or unnecessary practices 48

49. Organizing for Infection Control Requires cooperation, understanding and support of hospital administration and medical/surgical/nursing leadership There is no simple formula: Every facility is different Every facility’s problems are different Every facility’s personnel are different The facility must develop its own unique program 49

50. Questions?

51. Thank You