infection control

1. Infection Control
• Introduction: Microorganisms exist everywhere: in water, in soil, and
on body surfaces such as the skin, intestinal tract, and other areas open
to the outside such as our mouth, upper respiratory tract, vagina, and
lower urinary tract. many organisms are harmless, others are lethal,
some are a normal part of our body.
• As such, the ones directly involved in providing a biologically safe
environment are none other than the nurses.

2. • Infection control addresses factors related to the spread of infections
within the healthcare setting (whether patient-to- patient, from patients
to staff and from staff to patients, or among-staff), including
prevention (via hand hygiene/hand washing,
cleaning/disinfection/sterilization, vaccination, surveillance),
monitoring/investigation of demonstrated or suspected spread of
infection within a particular health-care setting (surveillance and
outbreak investigation), and management (interruption of outbreaks).

3. Definition of infection:
1. The invasion of bodily tissue by pathogenic microorganisms that
proliferate, resulting in tissue injury that can progress to disease.
The invasion and multiplication of microorganisms such as bacteria, viruses,
and parasites, that are not normally present within the body. An infection may
cause no symptoms and be subclinical, or it may cause symptoms and be
clinically apparent.
2. Infection is the growth of microorganisms in body tissue where they are
not usually found.
• An infection may remain localized, or it may spread through the blood or
lymphatic vessels to become systemic (body wide). Microorganisms that
live naturally in the body are not considered infections. For example,
bacteria that normally live within the mouth and intestine are not
infections.)

4. • Infection prevention: Infection prevention refers to policies and
procedures used to minimize the risk of spreading infections,
especially in hospitals and human or animal health care facilities.
• Infectious diseases: Infectious diseases kill more people worldwide
than any other single cause.
• Infectious diseases are caused by germs. Germs are tiny living things
that are found everywhere - in air, soil and water. Person can get
infected by touching, eating, drinking or breathing something that
contains a germ.

5. • Germs can also spread through animal and insect bites, kissing and
sexual contact. Vaccines, proper hand washing and medicines can help
prevent infections.
• Types of Microorganisms
• Four major categories of microorganisms cause infection in humans:
bacteria, viruses, fungi, and parasites.
• Bacteria. bacteria are by far the most common infection-causing
microorganisms; several hundred species can cause disease in humans
and can live and be transported through air, water, food, soil, body
tissues and fluids, and inanimate objects.
• Viruses. Viruses consist primarily of nucleic acid and therefore must
enter living cells in order to reproduce; common virus families
include rhinoviruses (causes the common cold), hepatitis, herpes, and
human immunodeficiency virus.

6. • Fungi. Fungi includes yeast and molds; Candida albicans is a yeast
considered to be normal flora in the human vagina.
• Parasites. Parasites live on other living organisms; they include
protozoa such as the one that causes malaria, helminths (worms), and
arthropods (mites, fleas, ticks).

7. Definition of some terms
Asymptomatic: If the microorganism produces no clinical evidence of
disease, the infection is called asymptomatic or subclinical.
Disease: A detectable alteration in normal tissue function is
called disease.
Virulence: Microorganisms vary in their virulence or their ability to
produce disease, the severity of the diseases they produce, and their
degree of communicability.
Pathogenicity: Pathogenicity is the ability to produce disease; thus, a
pathogen is a microorganism that causes disease.
Asepsis: Asepsis is the freedom from disease causing microorganism;
aseptic technique is used to decrease the possibility of transferring
microorganisms from one place to another.

8. Medical asepsis: Medical asepsis includes all practices intended to
confine a specific microorganism to a specific area, limiting the number,
growth, and transmission of microorganisms.
Surgical asepsis: Surgical asepsis, or sterile technique, refers to those
practices that keep an area or an object free of all microorganisms; it
includes practices that destroys microorganisms and spores.
Sepsis: is the condition in which acute organ dysfunction occurs
secondary to infection.

9. Types of infection
Infection occurs when newly introduced or resident microorganisms
succeed in invading a part of the body where the host’s defense
mechanisms are ineffective and the pathogen causes tissue damage.
Primary infection: Initial infection with an organism to host constitutes
primary infection.
Secondary infection: When in a host whose resistance is lowered by
pre-existing infection, a new organism may set up a new infection.
Local infection: Infection that is limited to a defined area or single
organ with symptoms that resemble inflammation (redness, tenderness
and swelling.)

10. Systemic infection: Infection that spreads to whole body resulting in a
septicaemia.
Acute infection: It appears suddenly or lasts for a short time. E.g. URI
Chronic infection: May occur slowly over a long period and may last
months to years.
Iatrogenic infection: Infection resulting due to therapeutic and
diagnostic procedures.

11. Nosocomial infection: Also known as Hospital-acquired infection (HAI) —
is an infection that is contracted from the environment or staff of a healthcare
facility.
It can be spread in the hospital environment, nursing home environment,
rehabilitation facility, clinic, or other clinical settings.
Infection is spread to the susceptible patient in the clinical setting by a
number of means.
Health care staff can spread infection, in addition to contaminated equipment,
bed linens, or air droplets.
The infection can originate from the outside environment, another infected
patient, staff that may be infected, or in some cases, the source of the
infection cannot be determined.

12. • Urinary tract. The most common microorganisms in the urinary tract
include Escherichia coli which occur as a result of
(improper catheterization technique),
Enterococcus species (contamination of closed drainage system),
and Pseudomonas aeruginosa (inadequate hand hygiene).
• Surgical sites. The most common microorganisms in surgical sites
include Staphylococcus aureus (inadequate hand hygiene),
• Enterococcus species including vancomycin-resistant strains
(improper dressing change technique), and Pseudomonas aeruginosa.
• Bloodstream. The most common bloodstream microorganisms include
coagulase-negative staphylococci (inadequate hand hygiene),
• Staphylococcus aureus and Enterococcus species (improper intravenous
fluid, tubing, and site care technique).

13. • Pneumonia. The most common causative microorganisms
for pneumonia include Staphylococcus aureus (inadequate hand
hygiene), Pseudomonas aeruginosa and Enterobacter species
(improper suctioning technique).

14. Chain of infection:
• The presence of a pathogen does not mean that an infection will begin.
In order for infectious disease to spread, several necessary steps must
occur. These steps are known as “chain of infection”.
• An infection will develop only if chain remains intact.
• These links are;
• Causative Agent Reservoir Portal of Exit Mode of Transmission
Portal of Entry Susceptible Host

16. • Causative Agent the microorganism (for example bacteria, virus or
fungi).

19. • Mode of Transmission - since microorganisms cannot travel on their
own; they require a vehicle to carry them to other people and places.
• Infectious diseases and even certain contagious diseases spread
through the following agencies. Their ways of spreading is also given
along with these agencies.
 Air-borne transmission
Contact transmission-direct and indirect
Vehicle transmission (Water, milk, food etc.)
 Vector-transmission
 Tran placental transmission

20. • Portal of Entry - a path for the microorganism to get into a new host,
similar to the portal of exit.
• Susceptible Host - a person susceptible to the microorganism

21. Who is at risk of infection?
• Staff: service provide are at significant risk for infection because they
are exposed to potentially infectious blood and other body fluids on
daily basis.
• Clients: they are at risk of post procedural infection when, e.g.
service providers do not wash hands between client and procedure,
when they do not adequately prepare client for procedure and when
used instruments and other items are not cleaned and processed
correctly.
• Community: it is also at risk of infection, particularly from
inappropriate disposal of medical waste.

22. Breaking chain of infection:
• As health professional, we cannot provide health care services without
some exposure to potentially infectious materials, but we can prevent
transmission in many cases.
• The only way to prevent infection is to break the chain of infection.
The nurse must follow certain principle and procedures to prevent
infection and control its spread.

23. • Breaking the chain of infection (1) :
1. Rapid and accurate identification of organism
2. Routinely send blood cultures, urine culture, skin swabs, throat
swabs, tracheal aspirate culture.
3. Send endotracheal tube tip, urinary catheter tip and central line tip
for culture after removal.
4. control or elimination of infectious agents including: Proper
cleaning by the water and mechanical action with or without
detergents.
5. Disinfection.
6. Sterilization of contaminated objects.

24. Breaking the chain of infection 2
• Measures to control or eliminate of reservoir of infection.
• Employee health:
• Immunization of health personnel’s e.g. hepatitis B vaccine
• Regular check-up for early detection of any communicable disease
• Restriction from work of patient contact when infected with
communicable disease.

25. Breaking chain of infection 2 cont…
Environmental disease:
• Cleaning with hospital approved clear disinfectant, e.g. phenol
• Thorough cleaning of bed and bedside equipment's before admitting
new patient.
• Separate mops should be used for cleaning of unit. (Twice a day).

26. Handling of linen:
• Keep bed sheets dry and clean.
• Change sheets every day.
• Do not shake blankets and linen.
• Do not throw them on floor.
• Soiled linen counting should be done in separate place.

27. Pest control:
Measures to be taken to avoid their entry into unit. E.g. proper cleaning,
sealing and draining.
Patient’s diet should be kept in covered containers.
Keep fly trappers on each bedside of patient.
Pesticide spray should be used weekly.
Visitors control:
• Traffic should be restricted except for doctor, nurse and supportive
staff.
• Allow only one attendant (3-4 hours).
• Keep the doors and windows closed.
• Mobile phones should not be allowed inside the area.

28. Breaking the chain of infection3;Portal of exit:
• Practice aseptic precaution.
• Avoid talking directly into the client’s mouth to prevent the droplet
infection.
• Wearing of mask is compulsory if the nurse is infected or she is
dealing with the patients who are infected.
• Careful handling of waste like urine, faeces, emesis and blood is
important.
• Disposable gloves should be worn to prevent direct contact with
wastes or infected materials.

29. Breaking the chain of infection 4: Mode of
transmission:
• Its called Contact Precautions
• Single patient room.
• Staff to perform hand hygiene, put on gown/apron and gloves prior to
entering patient room and when anticipating contact with the patient or
their surroundings is.
• Remove gown/apron and gloves and perform hand hygiene after
leaving room.
• Clean and disinfect non-disposable equipment and items when
removed from patient room.

30. Droplet Precautions;
Single patient room.
Staff to put on surgical mask when entering room and remove and
dispose of mask after leaving room and perform hand hygiene.
Instruct patient about respiratory hygiene and cough etiquette.
Limit patient movement outside the room to medically-necessary
purposes.
Patient to put on a surgical mask when leaving room.

31. Airborne Precautions
Single negatively pressured room.
Door to remain closed.
Staff to put on N95/P2 mask when entering patient room and remove
and dispose of mask and perform hand hygiene after leaving room.
Instruct patient about respiratory hygiene and cough etiquette.
Patient to put on surgical mask when leaving room.

32. Breaking the chain of infection 5: Portal of
entry:
• Maintain integrity of skin and mucous membrane.
• Prepare position of tubing, etc. may prevent injuries and skin
breakdown.
• Turning and positioning of debilitated clients.
• Ensure the personal hygiene of client regularly.
• Proper disposal of contaminated syringe and needles.
• Proper handling of catheters and drainage set etc. care should be taken
while collecting and handling specimen.

33. Breaking the chain of infection 6 : Protecting
susceptible host:
Protecting the normal defence mechanism by;
• Regular oral hygiene.
• Encouraging deep breathing exercise.
• Encouraging proper immunization of children and adult client.
Maintaining healing process:
Promotion of intake of well-balanced diet containing essential protein,
vitamins, fats and carbohydrates.
Institution measures to improve appetite of patient.
Helping the client to identify methods to relieve stress.

34. Defenses Against Infection
• Individuals have defenses that protect the body from infection;
• they are categorized as specific and non specific defenses.
Nonspecific Defenses
• Nonspecific defenses protect the person against all microorganisms,
regardless of prior exposure; they include anatomic and physiologic
barriers and the inflammatory response.

35. • Anatomic and Physiologic Barriers
• Intact skin and the mucous membranes are the body’s first line of defense
against microorganisms.
• The nasal passages have a defensive function: moist mucous membranes
and cilia trap microorganisms, dust, and foreign materials.
• The lungs have alveolar macrophages (large phagocytes); phagocytes are
cells that ingest microorganisms, dead cells, and foreign particles.
• The oral cavity regularly sheds mucosal epithelium to rid the mouth of
colonizers.
• The flow of saliva and its partial buffering action help prevent infections;
saliva contains microbial inhibitors, such as lactoferrin, lysozyme.

36. Anat and phys barr cont…
• The eye is protected from infection by tears, which continually wash
microorganisms away and contain inhibiting lysozyme.
• The high acidity of the stomach normally prevents microbial growth.
• The resident flora of the large intestine help prevent the establishment of disease-
producing microorganisms.
• Peristalsis also tends to move microbes out of the body.
• When a girl reaches puberty, lactobacilli ferment sugars in the vaginal secretions,
creating a vaginal pH of 3.5 to 4.5; this low pH inhibits the growth of many disease-
producing microorganisms.
• The entrance to the urethra normally harbors many microorganisms; urine flow has
a flushing and bacteriostatic action that keeps the bacteria from ascending the
urethra; an intact mucosal surface also acts as a barrier.

37. Inflammatory Response
• Inflammation is a local and nonspecific defensive response of the tissue to an
injurious or infectious agent; it is an adaptive mechanism that destroys or
dilutes the injurious agent, prevents further spread of the injury, and promotes
the repair of damaged tissue.
• First stage: Vascular and cellular responses. There is constriction of blood
vessels, dilatation of small vessels, increased vessel permeability, increased
leukocytes, swelling, and pain; leukocytes begin to engulf the infection.
• Second stage: Exudate production. This stage is characterized by exudation
with fluids and dead cells; serous (clear, part of the blood), purulent (thick,
pus with leukocytes), and sanguineous (bloody).
• Third stage: Reparative phase. The repair of tissues; examples are
regeneration (same tissues), stroma (connective tissues), parenchyma
(functional part), and fibrous (scar).

38. • Specific Defenses
• Specific defenses of the body involve the immune system; the immunes
response has two components: antibody-mediated defenses and cellular-
mediated defenses.
• Antibody-Mediated Defenses
• Another name for the antibody-mediated defenses is humoral (or circulating)
immunity because these defenses reside ultimately in the B lymphocytes and
are mediated by antibodies produced by B cells.
• Active immunity. In active immunity, the host produces antibodies in response
to natural antigens (e.g. infectious agents) or artificial antigens (e.g. vaccines);
B cells are activated when they recognize the antigen; they the differentiate into
plasma cells; the B cell may produce antibody molecules of five classes of
immunoglobulins: IgM, IgG, IgA, IgD, and IgE.
• Passive immunity. With passive (or acquired) immunity, the host receives
natural (e.g. from a nursing mother) or artificial (e.g. from an injection of
immune serum) antibodies produced by another source.

39. • Cell-Mediated Defenses
• The cell-mediated defenses, or cellular immunity, occur through the T-
cell system.
• On exposure to an antigen, the lymphoid tissues release large numbers
of activated T-cells into the lymph system.
• These T-cells pass into the general circulation.
• There are three main groups of T-cells: helper T cells, cytotoxic T
cells, and suppressor T cells.
• Helper T cells help in the function of the immune system.
• Cytotoxic T cells attack and kill microorganisms and sometimes the
body’s own cells.
• Suppressor T cells suppress the functions of the helper T cells and
cytotoxic T cells.

40. STANDARDSAFETY MEASURES
Also known as Standard precaution or Personal Protective Equipment
Introduction:
Universal precautions refers to the practice, in medicine of avoiding contact with
patients' bodily fluids, by means of the wearing of nonporous articles such as
medical gloves, goggles, and face shields. The practice was introduced in 1985–
88.
In 1987, the practice of universal precautions was adjusted by a set of rules
known as body substance isolation.
In 1996, both practices were replaced by the latest approach known as standard
precautions.

41. Definition:
Standard precaution is defined as, “a set of precautionary measures including good
hand hygiene practices and use of protective barriers during routine patient care
carried out by health care workers (HCW)”.
Under universal precautions all patients were considered to be possible carriers of
blood-borne pathogens.
Pathogens fall into two broad categories, blood borne (carried in the body fluids)
and airborne.
 Standard precaution contains following things;
Hand washing
Gloving
Gowning
Mask/ protective eye wear/ cap
Shoe cover

61. • Disinfecting. The first links in the chain of infection, the etiologic
agent and the reservoir, are interrupted with the use
of antiseptics (agents that inhibit the growth of some microorganisms)
• and disinfectants (agents that destroy pathogens other than spores) and
by sterilization; both antiseptics and disinfectants are said to have
bactericidal or bacteriostatic properties;
• A bactericidal preparation destroys bacteria, whereas a bacteriostatic
preparation prevents the growth and reproduction of some bacteria.

62. • Sterilization. Sterilization is a process that destroys all microorganisms,
including spores and viruses;
Four commonly used methods of sterilization are:
1. Moist heat: (to sterilize with moist heat, steam under pressure is used because
it attains temperatures higher than the boiling point)
2. Gas: (ethylene oxide gas destroys microorganisms by interfering with their
metabolic processes)
3. Boiling water: (this is the most practical and inexpensive method for
sterilizing in the home)
4. Radiation: (both ionizing and non-ionizing are used for disinfection and
sterilization.

63. Sterile Technique
• An object is sterile only when it is free of all microorganisms.
• It is well known that sterile technique is practiced in operating rooms and
special diagnostic areas.
• Sterile technique is also employed for many procedures in general care areas
such as when administering injections, changing wound dressings,
performing urinary catheterization, and administering intravenous therapies.
• In these situations, all principles of the surgical asepsis are applied as in the
operating or delivery room; however, not all of the sterile techniques that
follow are always required.

64. Principles of Surgical Asepsis
• All objects used in a sterile field must be sterile.
• Sterile objects become unsterile when touched by unsterile objects.
• Sterile objects that are out of sight or below the waist or table level
are considered unsterile.
• Sterile objects may become unsterile by prolonged exposure to
airborne microorganisms.
• Fluids flow in the direction of gravity.
• Moisture that passes through a sterile object draws microorganisms
from unsterile surfaces above or below to the sterile surface by
capillary action.
• The edges of a sterile field are considered unsterile.
• The skin cannot be sterilized and is unsterile.
• Conscientiousness, alertness, and honesty are essential qualities in
maintaining surgical asepsis.

65. Assignment 2
Briefly explain the concept of biomedical waste 5 Marks