Abstract

The veterinary nurse (VN) plays an invaluable role in controlling the biosecurity protocols of the veterinary hospital. Biosecurity is a critical component of veterinary practice in order to prevent cross-infection between patients, nosocomial infections (infections acquired while in hospital) and zoonoses (diseases that can spread between animals and man). Many patients present to the hospital with infectious diseases and these patients should be identified as quickly as possible, isolated and high level biosecurity measures be put in place. There are numerous products on the market that are suitable for use in the veterinary practice and the nurse should familiarise herself with their individual properties in order to select the best product for the specific situation.

Introduction

Biosecurity is defined as a set of preventive measures designed to reduce the risk of transmission of infectious diseases. It includes general disinfection of the buildings, instruments, equipment, and cages as well as sterilization of surgical instruments, isolation protocols, and disinfection of potential fomites such as shoes and clothing.

The three most common routes for the spread of infection are on the hands of the staff, on fomites (inanimate objects such as shoes, blankets, stethoscopes, etc.), and on dust particles or aerosolized droplets from the respiratory tract. The protocols discussed in this presentation are based on those of the Onderstepoort Veterinary Academic Hospital (OPVAH).

There are three classes of products used in biosecurity:

 Detergents - remove dirt, grease, body fluids, and other organic materials

 Disinfectants - remove and destroy microorganisms in the environment

 Antiseptics - remove or destroy microorganisms on the skin

The product chosen should take a multitude of factors into account:

 Effectivity against a wide range of organisms

 Effectivity in the presence of organic and inorganic substances

 Toxic or irritant side effects

 Staining or corrosive effects

 Stability once made up

 Contact time needed

 Cost

General Disinfection of the Practice

Although there will most likely be assistants to carry out the physical cleaning, the VN should play a hands-on role in supervising the disinfection protocol. Assistants should be educated as to why they are carrying out the specific tasks and made aware of the value and importance of their work. This will decrease the human tendency to take shortcuts and thus optimize the efficacy of the disinfection team. It can be difficult for people without veterinary training to understand the concept of invisible microorganisms and the importance of repeated disinfection of areas that still appear to be macroscopically clean.

The OPVAH uses F10SCXD for surface disinfection of floors, walls, cages, etc. (areas where cleaning as well as disinfection is necessary).

Floors are cleaned daily and spot-cleans performed after any soiling by animal waste or other possibly infectious materials.

Areas that are touched often by staff (these areas include computer keyboards, lab equipment, door handles, etc.) as well as all surfaces are wiped down daily with F10SC. This product is a non-staining disinfectant without added detergent. Surfaces contacted by patients such as examination tables are wiped down between patients.

Cages are thoroughly cleaned with detergent and water and then with F10SC between patients and cages that have stood empty for more than 1 week are wiped down with F10SC. Blankets and cage furniture are also disinfected after every use.

Regularly used equipment such as thermometers, stethoscopes, probes, patella hammers, etc. can either be sprayed down or soaked in a suitable disinfectant depending on the instrument.

Sterilization

Specialised protocols are required and use may be made of an autoclave, ethylene oxide gas, or cold sterilization with glutaraldehyde. Advice on exact usage of each technique should be sought from the manufacturer. Remember that sterilized articles have a shelf life. Sterilization date must be marked on each article and they should be re-sterilized, even if unused, before expiry. Shelf lives differ depending on the sterilization technique used. Marking tapes or strips that change colour when effective sterilization has occurred are packed with each parcel to alert the VN to problems with the process.

Monitoring

Assistant staff should be trained to complete rosters with a signature to indicate that they have performed each task. Random monitoring with swabs and cultures is also recommended to pick up signs of resistant organisms or failures in the protocols. This monitoring needs not be performed more than once or twice a year unless disinfection failure is suspected with a case of nosocomial infection or a zoonosis occurring.

Patient Management

Basic personal hygiene, such as hand washing with an antimicrobial soap between patients and the use of easily disinfected outer clothing, must be maintained. Overshoes and disposable gowns as well as gloves are indicated when working with known infectious cases such as patients with parvovirus, distemper, Salmonella or Chlamydophila. Masks must be used when the patient has a zoonotic disease known to be airborne such as Chlamydophila or tuberculosis. Isolation units need special management:

 Separate room with separate air conditioning to rest of hospital, preferably HEPA filters

 Cage labels giving the animal's condition

 Protective gear worn and discarded when leaving the unit

 Separate cage furniture and equipment to rest of hospital

 Footbaths at the exit

 Preferably separate staff, alternately staff must treat infectious patients after all others

 Isolation staff may not handle neonates, geriatric or critical patients

Critical patients are immunosuppressed due to the physiological stress of their conditions. Invasive treatments such as intravenous lines and catheters penetrate the integument and provide access points for pathogens.

Strict asepsis should be adhered to while dealing with IV lines, catheters, injections, ET tubes, etc. Asepsis is defined as the state of being free of disease-causing organisms, because the skin can never be truly sterilized due to the presence of millions of bacteria resident in the skin. These bacteria rarely cause infection. Skin cleaning is aimed at removing transient microorganisms and lowering the numbers of resident or commensal organisms. Hands should be washed in antimicrobial soap and ports should be swabbed with Hibitane® in alcohol or another suitable product before injections are administered. Needles and syringes must not be reused. The skin should be properly prepped before catheter placement and gloves worn while placing it. Wound care is another area where asepsis is important. Once again, gloves should be used when changing dressings and dressings in contact with the wound must be sterile.

Conclusion

Proper biosecurity is a critically important aspect of veterinary practice and the veterinary nurse is in the ideal position to ensure that disinfection and sterilisation practices are of the highest level possible. She must train the veterinary assistants so that they understand the reasons for the biosecurity measures for which they are responsible. Constant vigilance is needed to detect possible biosecurity failures and correct them before they lead to negative consequences. As the VN is often the person that administers treatments to patients and dresses wounds, adherence to the principles of biosecurity will minimise the chances of nosocomial infections. The VN has a responsibility towards the rest of the staff in ensuring zoonotic diseases are properly managed so as not to pose a risk to the health of the team. There are excellent books available on practice biosecurity and representatives of the companies supplying the products used will always be happy to offer advice on their use. With a dedication and attention to detail, the VN will be able to make the practice a clean and safe environment for both the patients and the staff.

References

1.  Orpet H, Welsh P. Handbook of Veterinary Nursing. Oxford, UK: Blackwell Publishing; 2002: 10–17.