Chain of infection

The development of infection can be thought of as a chain of events. Each event is a link in the chain and must occur sequentially for an infection to develop. The presence of all the following elements is necessary for an infection to occur:

Figure 20.1 The chain of infection. Infection prevention and control is directed towards breaking the links in the chain of infection

(Courtesy of Teresa Lewis)

Table 20.2 Interrupting the chain of infection

(Adapted from deWit 2009)

Contact transmission

Contact is the most common mode of transmission; it may be direct or indirect.

Direct transmission occurs when there is transfer of the infectious agent from one person to another; for example, a client’s blood entering the healthcare worker’s body through a needlestick injury.

Indirect transmission involves the transfer of infectious agent through a contaminated object or person; for example, a healthcare worker’s hands touching an infected body site on one client and the worker not performing hand hygiene before touching another client, or when a healthcare worker comes in contact with fomites (e.g. bedding of a client with scabies).

Clinical note: Some examples of infectious agents transmitted by the contact mode include multi-resistant organisms (MROs), norovirus, Clostridium difficile and highly contagious skin infections such as impetigo and scabies.

Droplet transmission

Droplet transmission occurs when the infected person coughs, talks, sneezes, laughs or during certain procedures. Droplet particles are larger than 5 microns in size. Distribution is limited by the force of expulsion from the infected person and is usually 1 metre. The droplet particles transmit infection when they travel directly from the infected person to a susceptible mucosal surface (nasal, conjunctivae or oral) of another person. However, droplets can be transmitted indirectly to mucosal surfaces (e.g. contaminated hands rubbing eyes or inserted into mouth).

Clinical note: Some examples of infectious agents that are transmitted via the droplet mode include influenza virus, pertussis and meningococcus.

Airborne transmission

Airborne dissemination may occur via tiny particle aerosols created during breathing, coughing, talking or sneezing containing infectious agents that remain infective over time and distance. Certain procedures, such as airway suctioning, endotracheal intubation, diagnostic sputum induction, positive pressure ventilation via face mask and bronchoscopy, can promote airborne transmission. The infective aerosols can be dispersed over long distances by air currents (e.g. ventilation or airconditioning systems) and inhaled by susceptible individuals who have had no contact at all with the infectious person.

Clinical note: Some infectious agents that are transmitted via the airborne mode include varicella virus (chickenpox), Mycobacterium tuberculosis and measles (rubeola).

Other modes of transmission

Transmission of infection can also occur via ingestion of contaminated food, water, medications or other common sources such as contaminated devices or equipment.

Clinical note: It is of great importance that nursing staff be aware of food being brought in to healthcare settings for clients by friends and family. If foods are not maintained at the correct temperature, the risk of food poisoning is very high. Foods of high risk include seafood, shellfish, soft cheeses and meat dishes. Facilities should have policies in place to help manage this (see Box 20.1).

Variant Creutzfeldt Jakob Disease (vCJD) is a disease that emerged in the UK in the 1990s. vCJD is linked to the consumption of meat products from cattle infected with bovine spongiform encephalopathy (BSE, or ‘mad cow disease’). Variant CJD is a separate disease to classical Creutzfeldt-Jacob disease (CJD) although some of the symptoms are similar. vCJD typically affects people at about age 30. The link between vCJD and ingestion of infected meat was discovered when 23 people living in Britain contracted CJD in the mid-1990s, about 10 years after the epidemic of bovine spongiform encephalopathy that occurred in the country from 1984 to 1986. No cases of variant CJD have been identified in Australia or New Zealand to date. Australian and New Zealand cattle remain free of BSE.

Vector-borne transmission (via mosquitoes, flies, rats and other animals) as a health concern is not as significant in Australia and New Zealand as it is in other parts of the world. However, in recent times there has been some increase in concern about transmission of Murray Valley encephalitis (MVE) and dengue fever in Victoria, western New South Wales and Far North Queensland. Examples of microorganisms spread by this mode in other parts of the world are Plasmodium falciparum (malaria) and Yersinia pestis (plague).

Resistance to infection

The body has certain natural resources that give a degree of resistance against infection. It has two main lines of resistance to infection: non-specific defences and a specific immune response. Non-specific defences are those that defend naturally against any invading organism or foreign matter. Such defence is also known as innate immunity, present at birth. It does not recognise specific microbes; it fights off all invading organisms in the same way. It provides us with rapid responses to protect against disease. These defences can be divided into two categories, external and internal. External physical barriers include intact skin, mucous membranes, normal body flora and some body secretions, for example, sweat, sebum, saliva and tears. Internal defences are the automatic protective actions of the inflammatory process, phagocytic cells, ‘natural killer’ cells and protective proteins. Inflammation is a localised and non-specific response of the tissues to an injury or infectious agent. It helps prevent further spread of injury, dilutes or destroys the injuring agent and promotes healing and repair of the injured tissues. It is characterised by five signs: pain, swelling, redness, heat and impaired function of the body part if injury is severe.

Specific defences defend against specific foreign agents or antigens, such as a specific bacterium, virus, pollen or toxins, once it has broken through the innate immunity defences. This defence is also known as adaptive immunity. Having immunity means being resistant to, or being unaffected by, a particular infectious disease. It means that a specific antibody has been produced to defend the body against a specific pathogen or the toxin it produces (the antigen). The body’s immune responses are under the control of the lymphatic system. It is a highly efficient system that responds very specifically to the threat of infection. It is made up of lymph, lymphatic vessels, lymph nodes, red bone marrow, the thymus gland, spleen and tonsils.

Lymphocytes are the most significant cells in the body’s immune responses. There are two categories of lymphocytes involved in the specific immune response: T-lymphocytes (T-cells) and B-lymphocytes (B-cells).

To function effectively in defending the body from invading organisms, these defence responses must be able to distinguish between the body’s own cells and foreign agents. Malfunction of a person’s immune system can cause a failure to recognise cells that belong to the self. This results in damage or destruction of ‘self’ cells. An attack on the body’s own cells is the basis of autoimmune disorders such as rheumatoid arthritis, juvenile-onset (type 1) diabetes mellitus, pernicious anaemia, multiple sclerosis and systemic lupus erythematosus (see Table 20.4).

Table 20.4 Types of immunity

Factors influencing susceptibility to infection

In a healthcare setting there are several factors that influence the individual’s outcome after exposure to a pathogenic organism:

Table 20.5 Factors that increase susceptibility to infection in older adults

Adapted from deWit 2009

An important component of nursing practice is assessing every client for existing infection or the potential for contracting an infection. There are some medical and drug therapies, such as corticosteroid medications or chemotherapy, which compromise immunity to infection. Nursing assessment of the client’s history to determine if there is an increased susceptibility to infection related to any medications or treatments is important. Clinical Interest Box 20.3 illustrates several questions that could be considered.

National Hand Hygiene Initiative

The Australian Commission on Safety and Quality in Health Care (ACSQHC) has instigated the National Hand Hygiene Initiative (NHHI) and assigned the responsibility of its delivery and rollout to Hand Hygiene Australia (HHA 2010). The key aim of the national initiative is to improve hand hygiene compliance among healthcare workers, and to reduce the transmission of infection in healthcare services throughout Australia. This involves a multi-faceted culture-change program to improve hand hygiene compliance through the increased use of alcohol-based hand rubs.

‘The 5 Moments for Hand Hygiene’ developed by WHO (2009) and adopted by Hand Hygiene Australia (Grayson et al 2009):

Figure 20.2 The ‘5 Moments for Hand Hygiene’ tool is based on evidence. It identifies when hand hygiene should be performed. That is, hand hygiene should be practised before every episode of client contact, including between different clients and between different care activities for the same client, and after any client activity or contact. The message for every healthcare worker is, perform hand hygiene before and after each patient contact or contact with the client environment

(© World Health Organization 2009. All rights reserved. Courtesy of Hand Hygiene Australia)

The 5 Moments for Hand Hygiene

Moment 1: Hand hygiene must be performed before touching a client

Moment 2: Hand hygiene must be performed immediately before a procedure

Moment 3: Hand hygiene must be performed following a procedure or potential body fluid exposure

Moment 4: Hand hygiene must be performed after touching a client

Moment 5: Hand hygiene must be performed after touching the client’s environment, without touching the client.

For ‘The 5 Moments for Hand Hygiene’ initiative to be effective, alcohol-based hand rub needs to be situated at point of use, for example, the end of the bed. Sustained, successful implementation of the initiative within the healthcare facility requires commitment and understanding from management, committed role models and champions throughout the facility, a team approach which should include not only the nursing sector but the medical practitioners as well and, most importantly, it requires understanding of the reason for the initiative and ownership of prevention of transmission of healthcare-associated infections by each stakeholder (Fig 20.3).

Figure 20.3 The 5 moments for hand hygiene can be applied in any healthcare setting, including the acute, day only, dental surgery, dialysis unit, nursery and clinic setting. The key emphasis is to perform hand hygiene before and after every episode of client contact, before and after any procedure and also after contact with the client’s environment. Hand hygiene must also be performed after the removal of gloves

(© World Health Organization 2009. All rights reserved. Courtesy of Hand Hygiene Australia)

Technique: is it important?

There are two recognised techniques for performing hand hygiene: hand hygiene with an alcohol-based hand rub and handwashing with soap and water (Figs 20.4 and 20.5).

Figure 20.4 How to use alcohol-based hand rub 1 Apply the amount recommended by the manufacturer onto dry hands 2 Rub hands together so that the solution comes in contact with all surfaces of the hand, paying attention to the tips of the fingers, the thumbs and the webbing between the fingers 3 Continue rubbing until the solution has evaporated and the hands are dry. Clinical note: This is of great importance when then donning gloves, because if hands are not dry, manipulation of gloves is very difficult and it may cause reactive dermatitis

(© World Health Organization 2009. All rights reserved. Courtesy of Hand Hygiene Australia)

Figure 20.5 How to handwash using soap (including antimicrobial soap) and water 1 Wet hands under running water and apply the recommended amount of liquid soap 2 Rub hands together for a minimum of 15 seconds so that the solution comes in contact with all surfaces of the hand, paying attention to the tips of the fingers, the thumbs and the webbing between the fingers (these areas are often missed during hand hygiene) 3 Rinse hands thoroughly under running water, and then pat dry with single-use towels. Moist skin becomes chapped readily

(© World Health Organization 2009. All rights reserved. Courtesy of Hand Hygiene Australia)

Clinical note: Effective hand hygiene relies on appropriate technique as much as on the selection of the correct product. If the technique is not appropriate this leads to failure of hand hygiene removing or killing microorganisms on the hands, despite the appearance of having complied with hand hygiene requirements.

Which product should be used?

Existing guidelines agree that hand hygiene using alcohol-based hand rubs is more effective against the majority of common infectious agents on hands than hand hygiene using plain or antiseptic soap and water. Such rubs can also be placed at point of use, are faster to use and the evidence shows they have better skin tolerability. The alcohol-based hand rub product must have Therapeutic Goods Administration (TGA) approval for skin antisepsis and meet the requirements of EN 1500 testing standard for bactericidal effect.

Does improved hand hygiene make any difference?

Recent evidence of improved hand hygiene has been associated with:

Hand hygiene practice alone is not sufficient to prevent and control infection and needs to be part of a multifaceted model to infection control. Figure 20.6 identifies the areas of the hands most often neglected during washing.

Figure 20.6 Areas most neglected when handwashing

Other aspects of hand hygiene

As intact skin is the first line of defence against infection, cuts and abrasions are a possible source of entry for infectious agents and reduce the effectiveness of hand hygiene practices. To reduce the risk of cross-transmission of infectious agents, cuts and abrasions should be covered with waterproof dressings.

An emollient hand cream provided for use at the healthcare facility should be used regularly, such as after performing hand hygiene before a break or going off duty. This assists in maintaining skin integrity. The effectiveness of hand hygiene can be impacted by the type and length of fingernails (Boyce & Pittet 2002; Lin et al 2003). Artificial nails have been associated with higher levels of microorganisms, especially gram-negative bacilli and yeasts than natural nails (Boszczowski et al 2005; Gupta et al 2004; Moolenaar et al 2000). It is recommended, therefore, that fingernails should be kept short, that is, the length of the finger pad, and dirt free, and artificial nails should not be worn. Studies have shown that chipped nail polish may support the growth of organisms on the fingernails (Grayson et al 2009) it is therefore good practice not to wear nail polish.

Although there is less evidence involving the impact of jewellery on the effectiveness of hand hygiene, rings can interfere with the technique used to perform hand hygiene, resulting in higher total bacterial counts (Boyce & Pittet 2002). Hand contamination with infectious agents is increased with ring wearing (Trick et al 2003). The consensus is to discourage the wearing of watches, rings or other jewellery during client care.

The Australian Guidelines for the Prevention and Control of Infection in Health Care (NHMRC 2010) suggest that each healthcare facility should develop policies about the wearing of jewellery (including body piercings), artificial nails or nail polish by employees. It is recommended that policies take into account the risks of transmission of infection to clients and healthcare workers, rather than cultural preferences.

Healthcare workers must also involve the clients and the visitors to the healthcare facility in hand hygiene. It is important that the clients’ hands as well as the nurses’ hands be cleansed before eating, after using the bedpan or toilet and after the hands have come into contact with any body substances, such as sputum or drainage from a wound. Strategically placed alcohol-based hand rub will assist with this.

Aprons and gowns

International guidelines recommend that protective clothing (apron/gown) be worn by healthcare workers when:

Clean, single-use, impervious, non-sterile, sterile, disposable, long or short sleeved? The type of gown or apron needed depends on the degree of risk and must be changed between clients.

Clinical note: Aprons and gowns must be removed before leaving the client-care area to prevent contamination of the environment outside the client’s room. Uniforms should be washed daily, even if aprons and gowns have been used.

Face and eye protection

As discussed earlier, the mucous membranes of the mouth, nose and eyes are portals of entry for infectious agents. Face and eye protection reduces the risk of exposure of healthcare workers to splashes or sprays of blood and body substances and is an important part of standard precautions.

Surgical masks are loose fitting, single-use items that cover the mouth and nose. They protect the person wearing them from splashes or sprays reaching the nose and mouth. Goggles provide reliable eye protection from splashes, sprays and respiratory droplets from multiple angles. Face shields provide protection to other parts of the face as well as the eyes.

Clinical note: Personal prescription glasses and contact lenses are not considered adequate eye protection. Newer styles of goggles are now available, that fit adequately over prescription glasses with minimal gaps.

Gloves

Gloves can protect both clients and healthcare workers from exposure to infectious agents that may be carried on hands. Hand hygiene should be performed before putting on gloves and after removal of gloves. Gloves are single-use items and should not be washed, but discarded. Gloves must be changed between clients and after every episode in individual client care. They should be put on immediately before a procedure and removed as soon as the procedure is completed. When removing gloves, care should be taken not to contaminate the hands. Gloves should be worn for each invasive procedure, for contact with sterile sites and non-intact skin or mucous membrane and for any activity that has been assessed as carrying a risk of exposure to blood, body substances, secretions and excretions. Glove use does not replace hand hygiene. Hand hygiene must always be performed after removal of gloves because gloves may have tiny defects and because hand contamination may take place during removal. Hands should be dry before donning gloves as skin reactions have been known to occur if hands are not dry under gloves.

Clinical note: Consideration of the task at hand and whether glove use is required is important, as latex sensitisation of healthcare workers is a risk. General research studies show a prevalence of 8–30% latex allergy among healthcare personnel worldwide (Manori 2010). Use of unpowdered latex gloves or latex free gloves may reduce the risk of increasing latex sensitisation. Figure 20.7 illustrates the correct method of removing contaminated gloves.

Figure 20.7 Removing contaminated gloves A: Removing the right glove. Take hold of the cuff on the glove on the right hand and slide it from the hand, folding the inside of the glove over the outside. This encloses the contaminated outside area. Avoid touching the skin of the right wrist or hand with the fingers of the contaminated glove on the left hand, as to do so would enable microorganisms to be transferred. B: Removing the left glove. Grasp the glove that has been removed from the right hand in the palm of the left gloved hand. Slip two fingers from the ungloved right hand under the band of the second glove at the wrist. Roll the glove off, turning it inside out, over the first glove. This action ensures that exposure of the contaminated surfaces on both gloves is minimal, reducing the risk of transferring microorganisms. C: Safe method of holding contaminated gloves. Ensuring that you hold and touch only the inside surface of the left-hand glove, drop the rolled up gloves into the appropriate receptacle for rubbish. The gloves should be disposed of in this way immediately after removal. This reduces the risk of spreading infection. Wash your hands promptly because there is no guarantee that gloves provide 100% protection. This also reduces the risk of developing an allergy to the latex in the gloves. Nurses who are left-handed may prefer to reverse this process.

(Courtesy of Teresa Lewis)

Hair covers

An elasticised paper cap is the most common hair covering. It is used whenever there is a risk of the hair becoming contaminated or if microorganisms from the hair might endanger the client. Nurses wear caps in the operating room environment and kitchen staff wear hair nets to prevent contamination of food.

Shoe covers

Disposable paper covers are worn over shoes whenever there is a risk of body substances splashing onto shoes during procedures. The covers are removed before leaving the room, to prevent pathogens being carried away from the area. Over-shoe cloth or paper covers are used in the operating room environment to contain any microorganisms that might be on the shoes of operating room staff.

To reduce the risk of transmission of infectious agents or contamination of self, PPE must be used appropriately. The sequence for putting on and taking off PPE is:

Figure 20.8 Sequence for removing PPE following airborne precautions. 1 Remove gloves (A & B) 2 Perform hand hygiene (C) 3 Remove eye protection (D) 4 Perform hand hygiene (E) 5 Remove long-sleeved gown, being careful not to contaminate uniform (F, G, H, I) 6 Dispose of gown (J) 7 Perform hand hygiene (K) 8 Step outside room and close door. Gently and carefully remove N95 mask (duck-bill mask) 9 Dispose of mask appropriately as in (J) 10 Perform hand hygiene (M)

(Courtesy of Teresa Lewis)

Sharps injury

If a sharps injury is sustained, how do you reduce the risk?

If a sharps injury happens to you, you can be reassured that only a small proportion of accidental exposures result in infection. Taking immediate action will lower the risks even further.

Clinical note: Client insulin pens brought into the healthcare facility pose a great risk to staff. Where possible, the client should self-administer their own insulin and remove and discard the used needle. If this is not possible, the facility should have policies in place which state the staff should administer the insulin from an insulin vial using a single-use insulin syringe instead of the insulin pen. (There are tools on the market which are designed to assist the client to remove the needle from the pen; however, they are not designed as a risk-reducing tool for staff use.) There have also been many reported incidents of injury to staff when retrieving the insulin pen from the bedside drawer, due to the insulin pen being placed back in the drawer with used exposed needle still in situ.

Disinfection

The first links in the chain of infection, the infectious agent and the reservoir, are interrupted by the use of antiseptics and disinfectants. Disinfection is not a sterilising process. It is a process intended to destroy pathogenic microorganisms (with the exception of spores) or render them inert, using either thermal (using heat and water, at temperatures that destroy infectious agents) or chemical means. Examples of disinfectants are alcohols, chlorine and chlorine compounds, formaldehyde, hydrogen peroxide, phenolics and quaternary ammonium compounds; they are used on inanimate objects. Disinfectants can be caustic and toxic to tissues. An antiseptic is a chemical preparation used on skin or tissue. Both disinfectants and antiseptics are said to have bactericidal or bacteriostatic properties. A bactericidal preparation destroys bacteria, whereas a bacteriostatic preparation prevents the growth and reproduction of bacteria. Different grades of disinfectants are used for different purposes. Spore-forming bacteria such as Clostridium difficile may be inhibited by only a few of the agents normally effective against other forms of bacteria. Each healthcare institution should have its own policy in relation to disinfection techniques.

Sterilisation

Sterilisation is a process that is intended to destroy all types of microorganisms, including bacterial spores and viruses. Four commonly used methods of sterilisation are moist heat, gas, boiling water and radiation. A sterile article is one that is totally free from all microorganisms. Sterility is an all-or-none state, because a single living cell renders an article unsterile.

Records of sterilisation must be kept to verify that an appropriate reprocessing system is in place according to state and federal legislation. Details of documentation required can be found in Australia Standards AS/NZ 4187 and AS/NZ 4815.

Storage and maintenance of sterile items

All sterile or high-level disinfected items must be stored in a way that maintains their level of reprocessing. Dry, sterile, packaged instruments and equipment should be stored in a clean, dry environment and protected from sharp objects that may damage the packaging. It is the nurse’s responsibility to check that the packaging of the sterile item about to be used has not been compromised.

Asepsis and infection prevention and control

Terminology historically has generated an inaccurate and confusing paradigm based on the terms sterile, aseptic and clean techniques.

Sterile: ‘Free from micro-organisms’ (Weller 1997).

Due to the large number of organisms in the atmosphere it is not possible to achieve a sterile technique in a typical healthcare setting. Near-sterile techniques can only be achieved in controlled environments such as laminar air flow cabinets or theatres. The commonly used term ‘sterile technique’, the instruction to maintain sterility of equipment exposed to air, is not possible and is often applied incorrectly.

Asepsis: ‘Freedom from infection or infectious (pathogenic) material’ (Weller 1997). It is defined as the absence of infectious agents that may produce disease.

Aseptic technique refers to practices used by healthcare workers to reduce the number of infectious agents; prevent or reduce the likelihood of transmission of infectious agents from one person or place to another; and render and maintain objects and areas as free as possible from infectious agents. It protects clients during invasive clinical procedures.

Clean: ‘Free from dirt, marks or stains’ (McLeod 1991).

Techniques used to maintain asepsis can be categorised into clean (medical asepsis) and sterile techniques (surgical asepsis).

Aseptic techniques are measures to lower the risk of infection by minimising the number of infection-producing microorganisms. The practices are classified as follows:

A clean/standard aseptic non-touch technique refers to routine work practices that reduce the numbers of infectious agents. Routine practices include hand hygiene, the use of barriers and environmental controls (no bed making or clients using commodes in the near vicinity) to reduce transmission of infectious agents, and the reprocessing of equipment between client use. Procedures requiring standard aseptic non-touch technique will characteristically be technically simple and short in duration (usually less than 20 minutes). They require a general aseptic field and non-sterile gloves. Examples are a simple wound dressing, insertion of a peripheral line and removing an endotracheal tube, sutures or drains (Fig 20.9).

Figure 20.9 Standard aseptic technique. To be used for a simple dressing. Review and carry out the standard steps for all nursing procedures/interventions. 1 Using neutral detergent: wipe down the dressing trolley/flat surface used to set up the aseptic dressing field (A & B) 2 Perform hand hygiene (C) 3 Open up commercially packaged sterile dressing pack (D) 4 Open the outer flap of the sterile package away from you (E) 5 Open the side flaps, one at a time, followed by the flap closest to you. Using this last flap gently manipulate the sterile tray and empty contents onto the field (F, G) 6 Open a commercially prepared sterile package (e.g. gauze). Hold the outer wrapping tightly, empty contents onto the sterile field. Take care not to contaminate the contents or aseptic field. (I, J) 7 Add sterile solutions to the aseptic field. Lean across the field over the shortest distance. Hold the container at a height to prevent splashing. Pour/squeeze from a single patient use container; discard any unused solution to prevent cross infection 8 Perform procedural hand hygiene (K) 9 Don PPE as per standard precautions 10 Using sterile tongs premoisten and squeeze out excess fluid from gauze (L, M) 11 Using tongs clean wound. Clean from inside out if possible, to prevent cross infection (N) 12 Have a waste receptacle at point of use (O) 13 Upon completion of dressing remove PPE and perform hand hygiene (P) 14 Dispose of PPE in waste receptacle (Q) 15 Wipe down the dressing trolley or surface that the sterile field has been set up on (R) 16 Perform hand hygiene (K)

(Courtesy of Teresa Lewis)

A sterile/surgical aseptic non-touch technique involves practices designed to eliminate the introduction of microorganisms into surgical incisions, tissues or wounds (e.g. use of sterile instruments, dressing materials and gloves, skin antisepsis and creation of a sterile field within which to operate). Procedures requiring surgical aseptic non-touch technique are technically complex, and involve extended periods of time. They are most often practised in the operating room, obstetric areas and major diagnostic or special treatment areas such as a burns unit or an intensive care unit. In the operating room, nurses follow a process to ensure that asepsis is maintained. A surgical aseptic technique may also be used by the nurse in a general medical or surgical unit or in a client’s home; for example, when performing a urinary catheterisation or redressing wounds. On these occasions it is not always necessary for the nurse to follow the above process in full, depending on the level of expertise and experience; for example, often only sterile gloves, a mask and a sterile field are needed, provided that the principles of surgical asepsis are maintained. To reduce the risk of microorganisms being transmitted via the respiratory route, talking by the nurse conducting any sterile procedure is kept to the absolute minimum.

Principles of surgical asepsis

Principles of surgical asepsis are applied when nurses create a sterile field, add supplies or liquids to a sterile field or don sterile gloves. The principles of surgical asepsis are that:

Creating a sterile field for a standard or surgical aseptic non-touch technique

The nurse creates a sterile field by using the inner surface of the cloth or wrapper that contains the sterile items as a work surface. This area is where the nurse places sterile equipment. The nurse must not contaminate the inner area. Before undertaking a procedure that needs a sterile field the nurse should:

Sterile items that have been packaged commercially are generally designed so that the outer paper or plastic wrapper can be torn away simply without contaminating the inner contents. The outer wrapper should be removed by tearing away from the body. Items sterilised within the facility may have an outer wrapper of thick strong paper or cloth. To open these items the nurse follows this procedure:

Adding sterile items to a sterile field

Sterile items can be added directly from their packaging onto the sterile field or by transferring them with sterile forceps. A packet containing a sterile item must be opened in such a way that the sterilised item does not come in contact with the non-sterile outer wrapper. The item may be gently allowed to fall onto a sterile field, with care taken not to contaminate the sterile field with the wrapper, or it may be retrieved directly from its packaging by a person holding sterile forceps or wearing sterile gloves (Fig 20.9).

Adding sterile solutions to a sterile field

Use of ‘once only’ solutions is best practice. Pour required amount onto the aseptic field in a manner that prevents splashing. Discard unused solution to prevent cross-infection. The basic principles employed in preventing the spread of infection are the same in all situations, regardless of whether clients are cared for in the community, in aged-care facilities, in day clinics or in hospitals. Standard and surgical aseptic techniques and all infection prevention and control activities are directed towards breaking the chain of infection. Figure 20.10 illustrates the procedure for open gloving. Closed gloving is the method used when sterile gloves are worn in conjunction with sterile gowns.

Figure 20.10 Donning sterile gloves. Review and carry out the standard steps for all nursing procedures/interventions. 1 Perform hand hygiene (A) 2 Remove outer glove bag by peeling sides away. Slide correct-size gloves, covered by inner paper wrapper, onto a clean dry flat surface above waist level 3 Perform procedural hand hygiene 4 Carefully move inner wrapper away to expose sterile gloves. Keep gloves on inside surface of the inner wrapper. Position gloves with wrist opening nearest to the body (B) 5 Identify the right and left gloves. Prepare to glove dominant hand first 6 Use thumb and first two fingers of non-dominant hand to pick up first glove. Lift at least 12 cm off wrapper (C) 7 Grasp the folded-over part of the cuff (each glove has a cuff about 5 cm wide that is folded back to reveal inside of glove). Take care to touch only the inside surface of the glove 8 Insert fingers of other hand into the held glove and pull the glove up over the dominant hand without touching the outer surface of the glove (D) 9 With gloved hand slide fingers underneath the cuff of the second glove (E) 10 Ease second glove up over non-dominant hand. Be careful not to touch outside of glove or other gloved hand with bare skin. Keep thumb of dominant hand abducted back. Once hand is settled in glove, slide cuff carefully up over the wrist, being careful to touch only the sterile sides (F) 11 Adjust fingers in gloves by pulling glove fingers out with the opposite hand to straighten and adjust until fitted neatly. Hands can be interlocked to help ease gloves into correct position (G)

(Courtesy of Teresa Lewis)

Specimen collection and transport

Standard precautions should be followed when handling laboratory specimens. If additional precautions are needed, for example, if the specimen is from a client diagnosed with a particularly virulent, unusual or epidemiologically important pathogen, such as Creutzfeldt-Jakob disease (CJD), advice should be sought from an expert in the pathology laboratory. The nurse should wear gloves when collecting specimens. Enrolled nurses (ENs) may be required to obtain specimens such as a midstream specimen of urine (MSU), wound swab or a stool (faecal) specimen. Other specimens that may be requested include swabs from wounds or body orifices such as the nose, throat or vagina. Personnel from a pathology department often obtain these or blood specimens from clients. ENs are advised to check their code of practice and the policies of the employing agency or healthcare facility with regard to collecting pathology specimens from clients. All specimen containers should be sealed tightly to prevent spillage and contamination of the outside of the container. Details should be written on the container label. The container should be placed in a sealed plastic bag, also clearly labelled, and taken as soon as possible to the pathology department. Hand hygiene must be performed upon removing PPE (Fig 20.11).

Figure 20.11 Collecting wound swab. Review and carry out the standard steps for all nursing procedures/interventions. 1 Perform hand hygiene (A) 2 Don PPE (B, C) 3 Open commercially packaged bacterial swabs (D) 4 Remove cap of transport medium container (E) 5 Carefully insert bacterial swab into the transport medium to premoisten swab (taking care not to contaminate swab) (F, G) 6 Remove swab from transport medium and gently roll over wound to be swabbed (H, I) 7 Gently insert the swab stick back into the transport medium (J, K) 8 Remove PPE (L, M, N) 9 Perform hand hygiene (O) 10 Write on outside of transport medium container (P) 11 Place inside pathology specimen bag (Q, R) 12 Perform hand hygiene (S)

(Courtesy of Teresa Lewis)

When are transmission-based precautions applied?

Transmission-based precautions are applied to clients in the presence of known or suspected infectious agents that are spread by direct or indirect contact, droplet or airborne routes. Whether used singly or in combination, transmission-based precautions are always applied in addition to standard precautions.

Indirect or direct contact transmission occurs when healthcare worker hands or clothing become contaminated, client-care devices are shared between clients, infectious clients have contact with other clients or environmental surfaces are not regularly decontaminated.

Droplet transmission occurs when healthcare workers’ hands become contaminated with respiratory droplets and are transferred to susceptible mucosal surfaces such as the eyes, when infectious respiratory droplets are expelled by coughing, sneezing or talking, and come into contact with another’s mucosa (eyes, nose or mouth), either directly into or via contaminated hands.

Airborne transmission occurs when healthcare workers or others inhale small particles that contain infectious agents.

Extra precautions are implemented to interrupt transmission of highly contagious or epidemiologically important pathogens that are transmitted via the respiratory droplet or airborne mode, direct or indirect contact mode or via any combination of these routes. For example, a client with influenza, active pulmonary TB, measles, Creutzfeldt-Jakob disease, vancomycin-resistant Enterococci or methicillin-resistant Staphylococcus aureus would be in this category.

Transmission-based precautions are also used in the event of an outbreak (e.g. gastroenteritis, whooping cough) to assist in containing the outbreak and preventing further infection. Transmission-based precautions are tailored to the specific infectious agent concerned and its mode of transmission and may include any combination of the following practices:

Contact precautions

Contact precautions consist of:

Droplet precautions

Droplet precautions consist of:

Airborne precautions

Airborne precautions consist of:

The aim of implementing transmission-based precautions early is to reduce further transmission opportunities that may arise due to the specific route of transmission of a particular pathogen. While it is not possible to identify all clients needing transmission-based precautions on admission, at times when an increased risk is recognised their use is warranted while confirmation is pending. When implementing transmission-based precautions the nurse must recognise there is potential for adverse effects such as anxiety, mood disturbances and perceptions of stigma and reduced contact with clinical staff. Clearly explaining to clients why these precautions are necessary may help to alleviate these effects. Clients and their carers should be offered clear, consistent information and advice through all stages of their care.

Isolation precautions

A client requiring transmission-based precautions is usually nursed using isolation precautions. Although healthcare facilities develop and implement their own isolation policies, isolation precautions are based on the following general principles:

Protective isolation

In some isolated cases, extremely immunocompromised clients may need to be protected from contracting infections and, therefore, must be protected from microorganisms carried into the room by those who enter. No one with an active infection such as a common cold is allowed in the room. Anyone who does enter is required to wear gown, mask, gloves and disposable coverings on the head and feet. When possible the client is nursed in a room with its own ventilation system. This would be implemented with the advice and attention of the infection control practitioner, as well as the medical officer caring for the client.

Preparation of client and family for isolation

Before isolation precautions are implemented, the client and significant others require thorough explanations about the precautions and the reasons for them. The information provided must be clear and comprehensive to prevent spread of infection through ignorance or carelessness. The information should be provided sensitively to reduce any feelings of embarrassment, resentment or apprehension that the client may experience. Clients should be given the opportunity to ask questions and have them answered in a clear and sensitive manner. Clients nursed in isolation may feel that they are a nuisance, are unclean or are afflicted with some disease that makes them unacceptable to others. Such clients may also be anxious that no one will come into their room to care for or visit them.

Because isolation may lead to withdrawal or sensory deprivation, the individual is reassured that measures will be implemented to provide adequate stimulation. The client should be provided with any means of diversion or intellectual stimulation that they need, such as a television set, telephone, books and magazines, craft projects or other forms of activity that may be of interest. Ideally the room should have an outside view as a means of reducing the client’s feeling of being isolated.

The client’s room should be set up with equipment that will remain in that room; for example, there should be a thermometer, stethoscope and sphygmomanometer that will be used only for that client. These items must remain in the room, and used only with the client being nursed in that room. Lined rubbish containers with lids and a soiled linen receiver are also placed in the room. Signage of transmission-based precautions must also be displayed.

Transporting clients requiring transmission-based precautions

It may be necessary to transport clients with infections to surgery or centres for diagnostic tests. Clients infected with microorganisms transmitted by the airborne route should only leave their rooms if it is essential to do so. Respiratory secretions should be contained by asking the client to wear a mask. The client should also be provided with tissues and a bag in which to seal them if necessary. The person transporting any client who is infectious should wear appropriate barrier protection. The nurse needs to take precautions to prevent and contain, or be ready to clean or cover, any leakage of body excreta (e.g. faeces, vomitus, sputum and urine), blood and other body fluids and exudates from infected wounds or skin lesions. The nurse provides the client with a clean (non-colonised) gown to wear as a robe en route and explains as sensitively as possible how the client can assist with preventing transmission of infection during the transfer and throughout any procedure. The client may be transported in a wheelchair or on a stretcher or hospital trolley. These may be protected with extra layers of linen or disposable protectors. Any person in another area who is to be in contact with the infectious client, such as ambulance officers and surgical staff, should be informed of the precautions necessary before the transfer. Information concerning the isolation precautions should also be clearly documented on the client’s chart. Equipment used should be cleaned according to infection control guidelines after use. While it is necessary to inform other care givers of the transmission-based precautions that are required, it is to be done with client confidentiality in mind.

Transmission-based precautions and multi-resistant organisms in outbreak situations

The application of transmission-based precautions is particularly important in containing MROs such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE) and multi-resistant gram-negative bacteria (MRGN) and is also an integral part of outbreak management.

An outbreak may be identified by a healthcare worker, by laboratory personnel or by health authorities conducting routine surveillance. An outbreak may be defined as an occurrence of more cases of disease than expected in a given area, among a specific group of people, over a particular period of time, or two or more linked cases of the same illness. Commonly detected outbreaks are: diarrhoeal pathogens (norovirus, Salmonella), respiratory pathogens (influenza), MRSA, Legionnaires’ disease, Clostridium difficile, chickenpox (varicella) and measles (rubeola).

Upon suspicion of an outbreak a quick infection control response is directly related to minimising cross-infection. Infection control strategies may differ according to the nature of the disease, the virulence of the organism and the vulnerability of the clients concerned.

Clinical note: Communication with the clients and their family or carers will alleviate anxiety and uncertainty. Clear and concise information highlighting the specific transmission-based precautions required to minimise cross-infection will allay fears. All facilities must have policies or guidelines in place for management of an outbreak.

Clinical Scenario Box 20.1 illustrates an example of the spread of infection due to inadequate adoption of standard precautions.

Preparation for discharge to the home environment

When clients are discharged from a healthcare setting the nurse has a responsibility to ensure that the client and family members have the knowledge and ability to control and prevent the onset or the spread of infection at home. Several social, demographic and cultural factors influence this knowledge and ability.

Factors affecting knowledge and ability to prevent and control infection

Factors that influence the ability of clients to absorb and retain information imparted to them include their age, educational level, language and cognitive abilities. Factors that influence a client’s ability to perform the infection prevention and control measures include their physical abilities, financial status and living conditions. Additionally a client’s cultural beliefs may impact on perceptions concerning the cause of infection and the need to comply with the recommended control measures. Assessing all these factors is essential when the nurse prepares a client for discharge home.

Living conditions and financial situation

Clients live in a range of different environments: some live in poverty—being homeless, or living in extremely poor conditions. Some of the most disadvantaged clients the nurse will encounter are Indigenous people, many of whom live in rural and remote areas where housing is inadequate and there is a lack of clean water because there is no mains water supply. Some live in overcrowded and unsanitary conditions where leakages of sewage are common (Human Rights and Equal Opportunities Commission Report 2006).

The lack of water and the lack of money impact on the ability of these people to:

See Chapter 9 for more information on issues that impact on health risks for Indigenous people.

Cultural beliefs

One of the most significant issues in infection control is an understanding of bacteria and viruses, how they spread and how they cause illness. This understanding of the cause of illness is widely accepted and understood in western cultures, but other cultures may have quite different perceptions. According to a person’s cultural beliefs, illness may be perceived as being a natural punishment for wrongdoing, caused by God’s will or by magical, mystical or spiritual intervention. Without the belief and understanding that illness is the result of bacterial or viral invasion there is little incentive for compliance with infection control measures dictated by western understandings. The nurse who tries to explain western perceptions to clients from other cultures may find language and cultural barriers difficult to overcome, and the help of an interpreter familiar with the culture and language of the client is strongly recommended.

Going home with an infection

The advantage of the home environment is usually that there is less exposure to the organisms that cause healthcare-associated infections and therefore, when poverty and clean water are not primary issues, the home usually presents less risk of infection than a hospital and it provides a healing environment. Before being discharged home, the client should be provided with the necessary education verbally and in written form. Some general points for client education in relation to preventing infection are identified in Clinical Interest Box 20.4.

If a client goes home with an infection, education appropriate to the specific type of microorganism and mode of transmission of the infection is essential. Education might need to include advising the client to:

Nurses frequently visit clients in their own home and often need to perform aseptic procedures such as wound dressing and catheterisation. Nurses may find it challenging in some homes to conduct such procedures without the advantages that the hospital provides, but the principles of asepsis must always be followed.

Responsibilities

Many healthcare facilities employ one or more members of staff to be responsible for the area of infection prevention and control. In a hospital a committee is often responsible. Individual nurses may be members of the committee, as may be representatives from the laboratory, housekeeping, maintenance, food services and laundry (if applicable). An important member of this committee is the infection control and prevention nurse. This nurse is specially trained to be knowledgeable about the latest research and practices in preventing, detecting and treating infections. In Australia the nurse should be a member of the Australian Infection Control Association (AICA). AICA is the peak national body representing the interests of the specialist practice of infection control within Australia. AICA represents the collaboration between the state and territory infection control associations throughout Australia. There is a move to have all Australian infection control and prevention practitioners credentialled (with AICA or the Certification Board of Infection Control and Epidemiology (CBIC)). In New Zealand the nurse should be a member of the New Zealand Nurses Organisation National Division of Infection Control Nurses (NDICN). The role of the infection prevention and control committee is to maintain surveillance of healthcare-associated infections throughout the hospital. All infections are reported to the infection control and prevention nurse in a manner that allows for recording and analysing statistics that can assist in improving infection control practices at the healthcare facility. The facility may have an infection control surveillance form in use, which will allow all nurses to highlight any possible infections to the infection control nurse (see Box 20.3).