How can communicable diseases be broken at a link within the communicable disease chain? Are there steps that a nurse can take to facilitate this process? Give a specific example. Use an example that is different than the postings of other students. There are six links in the Chain of Infection. Those areas include:
1. The infectious agent itself-
2. The reservoir where the infectious agent can live and multiply or lie dormant until the organism can find the opportunity to cause disease
3. The susceptible host
4. A means of Transmission
5. A portal of exit
6. A portal of re-entry Each link in this chain must be intact for a disease to be transmitted and infect another person. There is the potential to defeat a communicable disease process by disrupting the link in this chain at any point along the way thus preventing infection in another person.
An example of the simplest chain of infection is an infected patient cared for by a health care worker who doesn't wash their hands before caring for another patient. Human sources of microorganisms are healthcare workers, patients themselves and visitors, any of whom may be individuals who are in some stage of an incubation period of a disease process, may already have a disease, or may be a chronic carrier of an infectious agent. The patient may be their own source of infection. (Baldwin, 2008) The bacteria must be able to find a susceptible host. Some individuals are immune to infection or are able to resist colonization by an infectious agent while others will develop a full blown clinical disease process. Then there are those who are able to establish a symbiotic relationship with the bacteria and become asymptomatic carriers. There are contributing factors that can influence whether a person will develop an infection. Some of these factors include age, underlying diseases, treatments with antimicrobial or other immunosuppressive agents, irradiation, surgical procedures that break the patient's first line of defense (the skin), indwelling catheters etc. (Baldwin, 2008) There are many steps a nurse can take to facilitate breaking the chain of infection. For my example, since I work in the Operating Room, I will speak about our sterile technique and the way we employ contact precautions in the event that we encounter a patient with MRSA.

The prevention of infections and multidrug-resistant organisms (MDROs) is a critical national focus, as an estimated 1.7 million health care-associated infections occur annually in the United States. AORN Recommended Practices recommends perioperative team members should “participate in a variety of quality assurance and performance improvement activities to help monitor and improve the prevention of infections and MDROs.” (Conner et al., 2012) Perioperative nurses should assume responsibility to monitor and improve cleaning and disinfection practices, participate in reporting infections and exposure incidents, monitor the proper use of Personal Protective Equipment (PPE), and participate in surveillance programs for Surgical Site Infections (SSI) to help reduce and prevent transmissible infections and contribute to a greater culture of safety. (Conner et al., 2012) There are five main routes for transmission of bacteria--contact, droplet, airborne, common vehicle and vector borne. In the operating room when we have a patient who comes to us with a known diagnosis of MRSA in a wound we must follow contact precautions. AORN’s Recommended Practices addresses contact precautions. Contact precautions should be used when providing care for patients who are known or suspected to be infected or colonized with microorganisms that are transmitted by direct or indirect contact with patients, or items and surfaces in patients’ environments (ex, herpes simplex, impetigo, infectious diarrhea, smallpox, MRSA and VRE. (Conner et al., 2012)
Contact precautions include many of the same elements found in the Standard Precautions requirements- including:
*Wearing gloves when caring for patients or coming in contact with items that may contain high concentrations of microorganisms.
*Wearing gowns when it is anticipated that clothing will have contact with infectious patients or items in the patients’ environment.
*Wearing a mask when it is anticipated that aerosolized exposure to infectious microorganisms is possible.
*Face protection (goggles, face shield) when it is anticipated that splash or sneezing exposure is possible.
*Ensuring that precautions are maintained during transport.
*Adequately cleaning and disinfection patient care equipment and items before use with each patient.
*When Patient transport is necessary, barriers (gown, gloves) should be used to reduce the opportunity for transmission of microorganisms to other patients, personnel, and visitors and to reduce contamination of the environment.
*Non-critical equipment (equipment that touches intact skin) contaminated with blood, body fluids, secretions, or excretions, should be cleaned and disinfected after each use, according to the institutions’ written policy. The use of dedicated (disposable) patient equipment may be indicated in some situations (anesthesia, PACU)
*Routine cleaning of environmental surfaces (floors, and walls) is adequate for inactivation of MRSA, VISA & VRE.

In the operating room we have to be particularly careful when we are working around a patient that is diagnosed with MRSA. In the surgical setting the transmission or potential transmission of this bacteria from one surgical patient to another has the potential for devastating if not catastrophic consequences.

Surgical Site Infections (SSI) account for 20% of all skin and soft tissue infections present among patients who are admitted to hospitals. The risk of mortality increases 2-11 fold in patients with an SSI. Additionally, the duration of post-operative hospitalization can be increased by up to 7-10 days because of an SSI. This creates a burden of increased cost to the patient and health care institutions of from $3000.00 to $29,000.00 in published studies. Staphylococcus Aureus is identified as the primary pathogen in 20% of SSI cases. An important point is that hospital data reported to the CDC from 1991-2002 indicated that the rate of SSI caused by S. Aureus increased from 16.6% to 30.9%, whereas MRSA isolates increased from 9.2% to 49.3% during this time period. Resistance has become a major factor and a major concern because SSI's caused by MRSA are typically more severe and have worse outcomes than those caused by methicillin-sensitive Staphylococcus Aureus (MSSA). (Santayana & Jourjy, 2011)

The AORN Recommended Practices cites methicillin-resistant S. aureus (MSSA) and vancomycin-resistant Enterococcus (VRE), and carbapane-resistant Enterobacteriaceae as MDROs presenting significant infection prevention challenges and emerging as serious public health concerns. (Conner et al., 2012)

Following aseptic technique is especially critical when caring for patients with hardy organisms such as MRSA.
The basic principles of Aseptic Technique during a surgical procedure include:
*All items used within the sterile field must be sterile.
*Sterile Persons may touch only sterile items or areas of the field. Unsterile persons may touch only unsterile items or areas of the field.
*Movement within or around the sterile field must not contaminate the field.
*Sterile gowns are considered sterile in the front, from the shoulder to the tabletop level of the sterile field, and at the sleeves, from the cuff to 2 inches above the elbow.
*Tables are sterile only at tabletop level
*Edges of a sterile container are considered unsterile once the container has been opened.
* A sterile barrier that has been permeated is considered unsterile (strike through)
* All items or areas of doubtful sterility are considered contaminated and unsterile. (Conner et al., 2012)

One of the other principles of the Operating Room that is key to our breaking the chains of the infection cycle include keeping the OR doors closed. The quality of the OR ventilation system can affect the risk of SSIs. The doors of the OR must remained closed as much as possible to promote the desired positive pressure within the room and limit personnel traffic. (Conner et al., 2012)

It is also very important for OR nurses to keep the patient normothermic during the operative procedure as much as possible. Mild hypothermia can cause vasoconstriction, decreased delivery of oxygen to the incision site, and impaired function of phagocytic leukocytes, increasing the risk of an SSI. We employ the use of warming devices and monitor the patient’s temperature to ensure that the patient’s temperature remains above 96.8F during the entire peri-operative experience. (Conner et al., 2012)

Another area that we focus on very closely during the patient’s peri-operative stay is glucose monitoring. Physiologic stress caused by surgery can increase blood glucose levels. If our patient has diabetes, their blood glucose levels will need to be monitored during the operative procedure and corrective insulin doses given PRN. (Conner et al., 2012)

As Operating Room Nurses we can break the chain in the following way:
INFECTIOUS AGENT: MRSA

RESERVOIR: Patient with MRSA in an open wound.

PORTAL OF EXIT: Drainage from the open wound or direct contact with the open wound during patient care.
Break in the chain!
OR Nurse uses proper handwashing techniques, wears protective gloves/PPE and handles bed linens properly.

MODE OF TRANSMISSION: MRSA bacteria left on surfaces in OR suite and/or on clothing/skin of OR personnel. Transferred onto hands by direct or indirect contact:
Break the chain!
OR Nurse wears proper PPE, performs proper handwashing, gloving and linen handling.
At the completion of the surgical procedure OR personnel engages in proper terminal cleaning of the OR suite and equipment between surgical cases. At Salem Hospital we change our scrubs after caring for a patient with diagnosed MRSA.

PORTAL OF ENTRY:
Break the Chain! Organisms isolated with the use of Surgical Asepsis (sterile technique), terminal cleaning of OR suite and surgical instruments, and body substance isolation. Surgical instruments are resterilized before use on subsequent patients.

SUSCEPTIBLE HOST: Break the Chain! Pre-operative prophylactic antibiotics given within 1 hour of the start of every surgical procedure for every patient per SCIP guidelines. Studies indicate that prophylactic antibiotic administration is most effective when given within one hour prior to the initial incision or within 2 hours if vancomycin is the required medication. This allows time for the medication to reach the tissue and establish proper serum levels before the skin incision thus reducing the incidence of infection. In a study at LDS Hospital in Salt Lake City 2,847 surgical patients were given prophylactic antibiotic therapy pre-operatively. It was found that the lowest incidence of post-op infection was associated with administration within one hour prior to skin incision. The risk of infection increased progressively with greater time intervals before or after the one hour time frame of the skin incision. Patients who received the antibiotics too soon (more than two hours prior to incision) had an infection rate of 3.8%. The patients who received antibiotics three hours after skin incisions had an infection rate of 3.3%. www.jointcommission.org
Keep patients warm during procedures. Monitor blood glucose if indicated. OR Personnel have not transferred MRSA bacteria from the prior patient to the next patient by paying careful attention to the details of Contact Precautions and Surgical Aseptic Technique.

The OR Nurse must never move from one patient to the next without washing hands. If caring for a known MRSA patient she must practice Contact Precautions, don the proper PPE equipment, dispose of it properly after use, engage in proper handwashing and change her scrubs. Ensure the OR suite is properly terminally cleaned before caring for the next surgical patient.

The goal: All patients protected due to chain of infection being broken.

References:
Baldwin, K. M. (2008, July/August). FAQs about SSIs [Magazine]. Nursing Made Incredibly Easy, 36-43. (Baldwin, 2008)
Santayana, E. M., & Jourjy, J. (2011, March). Treatment of Methicillin-Resistant Staphylococcus aureus Surgical Site Infections [Magazine]. AACN Advanced Critical Care,22(1), 5-12. Retrieved from www.nursingcenter.com (Santayana & Jourjy, 2011)
Conner, R.,Blanchard, J., Burlingham, B., Denholm, B., Giarrizzo-Wilson, S., Ogg, M., & VanWicklin, S. A. (2012) Perioperative Standards and Recommended Practices 2012 Edition. K. Retlaff (ED.), Perioperative Standards and Recommended Practices-For Inpatient & Ambulatory Settings (2012, pp. 341-351). Denver, CO: AORN (Conner et al., 2012) www.cdc.gov www.jointcommission.org

Author: Candace Tiley CRNFA for RN-BSN education GCU