Infection Control Cycle

Breaking the infection cycle is everyone’s responsibility. To effectively break this cycle, Medical Assistants must first have a firm understanding of what this cycle involves, and once grasped, can identify and resolve indirect and direct transmission risks within patient care and clinic environments. The infection cycle has five key points where the Medical Assistant can intervene.

The first point in the infection cycle is the source reservoir, which refers to a person, animal, or any complex organism.¹ Each source may contain bacteria, fungi, parasites, and viruses that can infect others. Understanding and recognizing this as a Medical Assistant will change how you view infection prevention. Source reservoirs can include a patient who brought their sick child with them to their annual exam, a patient who brought their dog to their appointment, a patient who just finished some yard work where they encountered poison oak and didn’t change their clothes before coming to their appointment. Naturally, patient factors are not the only potential source reservoirs. Vendors and other employees can also be included in this list of source reservoirs.

The second point in the infection cycle is how or where a pathogen leaves the host, also known as the exit from reservoir¹. Sometimes, this is obvious, like coughing or sneezing, but other times, this is more difficult to identify. Either way, the pathogen will be transmitted from a mucous membrane or an opening in the host's body. For example, conjunctivitis is transmitted from the eyes, chlamydia is transmitted from the genitals, mononucleosis is transmitted from saliva, and hepatitis is transmitted through blood. These examples are seen in healthcare in various clinics, including family medicine, OB/GYN, pediatrics, urology, and optometry. Regardless of the clinical setting, MAs will see and need to know how to prevent transmission from patient to patient and from patient to staff.

The vehicle of transmission is the third point in the infection cycle. This point includes both direct and indirect transmission. The transmission of the pathogen considers the journey pathogens take from the source reservoir, out the portal of exit, to their new host. Direct transmission describes pathogens moving directly from the source, without deviation or pit stops, to the next susceptible host. Examples of direct transmission seen in healthcare are touching a bleeding wound without a barrier, providing rescue breaths in CPR without a barrier mask, handshakes, and inhaling infected droplets after a cough or sneeze. In contrast, indirect transmission is more devious, with pathogens waiting on surfaces even after the source reservoir is gone. This includes mucous from the nose or mouth that has been sneezed or coughed up and then settles on surfaces, blood droplets on an exam table after wound care, and transient organisms from hands settling on chairs or door handles.

Similar to point two, infection cycle point four is the portal of entry to a new host. Just as a pathogen seeks an opportunity to leave the source reservoir, the opportunity to enter the new host must be available for the infection cycle to continue. For example, a Medical Assistant is collecting a nasopharyngeal swab for suspected COVID-19 or influenza. The collection of this swab often causes the patient’s eyes to water or the urge to sneeze. If the Medical Assistant has their eyes, nose, or mouth exposed, they could easily take infected droplets into their exposed portal of entry. In this scenario, the patient cannot wear a mask covering the portal of exit in order for the swab to take place, and the expelling of infected droplets into the air is the vehicle of transportation. This is an example of direct transmission if breathed in directly by another person. If the droplets settle on the armchair and another person touches the armchair and rubs their face, this would be an example of indirect transmission. 

Finally, point five of the infection cycle is the susceptible host. This brings us full circle since the susceptible host can easily become the new source reservoir in the infection cycle if the links from one point to the next are not broken. A susceptible host refers to a person who is able to become infected by a pathogen. The human immune system exists so that we are not taken ill by every pathogen that we come into contact with; the immune system prevents the pathogen from taking hold. Immunocompromised individuals are at greater risk for being susceptible hosts due to circumstances beyond their control, including the elderly, chemotherapy patients, or transplant patients¹. Even those who consider themselves generally healthy can be susceptible hosts due to immune system-compromising behaviors like increased stress and sleep deprivation¹. Simple and controllable measures for preventing or reducing the susceptibility of a host would be maintaining good hygiene, receiving routine health care, getting enough rest, finding ways to manage stress, receiving adequate nutrition, and receiving routine vaccinations recommended by healthcare providers.   

Now that we have examined the infection cycle, we must consider the MA’s role in breaking this hazardous cycle. Medical asepsis, PPE, disinfection, and sterilization are the highlights of infection control. Medical asepsis refers to a clean technique, hand hygiene, reducing or eliminating as best as possible pathogens from an environment.² PPE, or personal protective equipment, includes rescue breath pocket masks, gloves, eye protection (goggles, face shields), disposable gowns, and masks of varying levels.³ Additional PPE may consist of lead aprons or earplugs in environments with X-rays or noisy equipment.³ Disinfection of exam rooms and discarding reusable supplies between patients are the most frequent daily tasks that most Medical Assistants perform to break the infection cycle. Sterilization is the highest level of disinfection and is utilized on tools that enter sterile fields of the body⁴. Preparing sterile fields, handling sterile equipment, and understanding what needs sterilization versus what needs high or low-level disinfection are all in the purview of the Medical Assistant. Implementing these tools properly and appropriately can break the infection cycle by blocking the portal of exit from an infection source reservoir with a mask, destroying pathogens in the route of indirect transmission, and removing pathogens from hands with the implementation of hand hygiene^2,3,4.

Interested in learning more? MArenew.com covers this and other relevant topics for Medical Assistants who need to get their recertification hours and Medical Assistants who want to expand their knowledge on up-to-date topics concerning MAs in healthcare today.

 

References:

1. Kronenberger, J., & Ledbetter, J. (2016). Lippincott Williams & Wilkins’ comprehensive medical assisting. Wolters Kluwer.
2. MEDICAL ASEPSIS, HAND HYGIENE, AND PATIENT CARE PRACTICES IN HOME CARE AND HOSPICE. (2006). Statewide Program for Infection Control & Epidemiology. Retrieved December 8, 2023, from https://spice.unc.edu/wp-content/uploads/2017/05/Module-F-HHH-2014.pdf
3. Personal Protective Equipment - Overview | Occupational Safety and Health Administration. (n.d.). https://www.osha.gov/personal-protective-equipment
4. Rutala, W. A., & Weber, D. J. (2016). Disinfection and Sterilization in Health Care Facilities. Infectious Disease Clinics of North America, 30(3), 609–637. https://doi.org/10.1016/j.idc.2016.04.002