[John-paul]

Thinking of your current or a past practice area provide an example of the train of transmission specific to that area. Fill in all ‘links’ in the chain with an example for each link:

Infectious Agent:

Reservoirs:

Portals of Exit:

Modes of Transmission:

Portals of Entry:

Susceptible Host:

[Modupe]

Chain of Transmission Example – Long-Term Care Home

Practice Area: Long-Term Care

Infectious Agent: Influenza (the flu) virus
Reservoir: A resident or staff member who has the flu, even if they are just starting to show symptoms.
Portal of Exit: The virus leaves the body through droplets when an infected person coughs, sneezes, or even talks.
Mode of Transmission: The virus spreads through close contact with an infected person or by touching contaminated surfaces and then touching the face without cleaning your hands.
Portal of Entry: The virus enters another person’s body through their nose, mouth, or eyes.
Susceptible Host: An elderly resident, particularly someone with a weakened immune system or an existing medical condition, who is more likely to become seriously ill.

This is why following Infection Prevention and Control (IPAC) practices is so important in a long-term care home. Simple actions like washing your hands, wearing the appropriate personal protective equipment (PPE), cleaning shared equipment, and staying home when you’re sick can help stop the chain of transmission and protect vulnerable residents.

Modupe Ogedengbe

[Edna]

I agree that older adults are more vulnerable to influenza, so it is important to follow IPAC practices every day. Your example clearly shows how simple actions like hand hygiene, wearing PPE, and staying home when sick can help protect residents and prevent the spread of infection. Hand hygiene can save lives

[Oluwatoyin]

Chain of Infection Example – Long-Term Care Home (Diarrhea)

Infectious Agent: C. difficile bacteria
Reservoir: A resident with diarrhea
Portal of Exit: Stool
Mode of Transmission: Dirty hands or contaminated equipment and surfaces
Portal of Entry: Mouth
Susceptible Host: Older residents with weak immune systems

Summary:

During my placement in a long-term care home, one resident had diarrhea caused by C. difficile. The bacteria came out in the resident’s stool. If staff did not wash their hands well or clean equipment properly, it could spread to other residents. Another resident could get infected if the bacteria entered through their mouth. Older residents are more at risk because their immune systems are weaker.

[Olubusayo]

As a healthcare worker in an LTC setting, I have found that this module has reiterated the importance of infection control, as we are dealing with older adults who are immunocompromised and more vulnerable to infections. It is essential to wash our hands with soap and water and not rely on alcohol-based hand sanitizers alone after providing peri-care to prevent the transmission of bacteria such as C. difficile.

[Nicole]

Infectious agent: Norovirus
Reservoir: Infected staff, residents or any contaminated surfaces
Portal of exit: Vomit or feces from the infected person
Mode of Transportation: Contact transmission through contaminated hands, shared equipment, or high touch surfaces.
Portal of entry: The mouth, when contaminated hands touch the face or the food that is consumed
Susceptible Host: Elderly residents, especially those with weakened immune systems or chronic health conditions

[Katelyn]

Great example! Norovirus spreads very easily in healthcare settings, especially through contaminated hands and high-touch surfaces, so your chain of transmission is clear and accurate. I also like that you identified older adults with chronic health conditions as a susceptible population, since they can become dehydrated much more quickly. This really highlights why hand hygiene, environmental cleaning, and proper PPE are so important in preventing outbreaks.

[Jieni]

Week 1 Post

Infectious Agent: Methicillin resistant Staphylococcus aureus (MRSA)

Reservoirs: MRSA may live on the skin or inside the nose of a patient without causing symptoms. It can also survive on bed rails, overbed tables, blood pressure cuffs, dressing carts, or reusable medical equipment if they are not cleaned properly.

Portals of Exit: MRSA can leave the body through drainage from an infected wound, pus from a skin infection, or contact with contaminated skin. When dressings are changed, bacteria can transfer to gloves or nearby surfaces.

Modes of Transmission: MRSA is mainly spread by direct contact. For example, a nurse changes a patient’s wound dressing and forgets to clean the stethoscope before using it on another patient. The bacteria can also spread through contaminated hands, gowns, or shared medical equipment.

Portals of Entry: MRSA commonly enters through broken skin, such as a surgical incision, an intravenous catheter site, a pressure injury, or another open wound.

Susceptible Host: Patients recovering from surgery are more susceptible because they have fresh surgical wounds. Older adults, people with diabetes, patients receiving chemotherapy, or those with weakened immune systems are also at greater risk of developing a MRSA infection after exposure.

[Oluwadamilola]

chain of infection example – LTC

Infectious Agent : SARS-CoV-2 , the virus responsible for causing COVID-19

Reservoir : A symptomatic or asymptomatic resident on the unit who tests positive for COVID-19 and sheds the virus through respiratory secretions

Portal of Exit : The infected resident’s respiratory tract, via coughing, sneezing, talking, or even normal breathing, which releases infectious respiratory droplets and aerosols into the air.

Mode of Transmission : Direct contact transmission specifically, the PSW’s contaminated gloved hands (after touching the infected resident or their immediate environment) that were not sanitized before donning new gloves, thereby carrying the virus to the next resident’s personal space. Indirectly, this could also occur via contaminated surfaces or shared equipment.

Portal of Entry : The next resident’s mucous membranes, specifically, their nose, mouth, or eyes where the virus gains access when they touch their face or when the PSW performs close-contact care .

Susceptible Host : An elderly resident on the same unit who is immunocompromised, has underlying conditions like diabetes, heart disease, or COPD, and is either unvaccinated or has waning immunity, making them highly vulnerable to severe infection if exposed.

[Rasheeda]

Practice Area: Long-Term Care

Infectious Agent: Varicella-zoster virus (VZV)

Reservoirs: Residents who have an active shingles outbreak with fluid-filled blisters.

Portals of Exit: Fluid from the shingles rash and blisters.

Modes of Transmission: Direct contact with fluid from the rash or, in some cases, airborne transmission from a person with a widespread rash.

Portals of Entry: Mucous membranes (eyes, nose, or mouth) or broken skin when exposed to the virus.

Susceptible Host: Older adult residents, and visitors especially those with weakened immune systems or those who have not had previous exposure or vaccination against varicella-zoster virus.

[Patience]

Practice area: Medical surgical unit

Infectious Agent: Staphylococcus aureus

Reservoirs: infected patients, healthcare workers’ hands, contaminated equipment

Portals of Exit: Drainage from wounds, respiratory secretions, skin lesions

Modes of Transmission: Direct contact with an infected person or indirect contact through contaminated hands or medical equipment

Portals of Entry: Broken skin, surgical incisions, intravenous catheter sites, mucous membranes

Susceptible Host: Hospitalized patients, especially those with weakened immune systems, recent surgery, or chronic illnesses

[Catherine]

Excellent examples of infectious agents! You have all touched on a variety of common infections and identified the routes of transmission as well as who is most susceptible. Understanding the types of infections that are circulating helps us to better protect ourselves, patients, and other team members, from the risks associated with becoming infected. Keep up the excellent engagement everyone with the learning material! Please remember, if you have any questions at any time about the learning material to email me at cvanveen@werpn.com.

[Olubusayo]

Infectious Agent: methicillin-resistant Staphylococcus aureus (MRSA)

Reservoir: A blood pressure cuff contaminated after being used on a resident colonized with MRSA.

Portal of Exit: MRSA is transferred from the resident’s skin to the blood pressure cuff during blood pressure measurement.

Mode of Transmission: Indirect contact when the contaminated blood pressure cuff is used on another resident without being cleaned and disinfected.

Portal of Entry: The contaminated blood pressure cuff comes into contact with the skin tear on a 90-year-old resident’s arm, allowing MRSA to enter the body.

Susceptible Host: A 90-year-old resident with a skin tear and an age-related weakened immune system, making them more vulnerable to infection.

[Harmanjyot]

Infectious Agent: Carbapenemase-Producing Organisms (CPO), such as carbapenemase-producing Klebsiella pneumoniae or Escherichia coli, which are resistant to many antibiotics.

Reservoirs: Colonized or infected patients, particularly those with prolonged hospitalizations, indwelling urinary catheters, wounds, or gastrointestinal colonization. CPO can also survive on contaminated environmental surfaces and shared medical equipment if not properly disinfected.

Portals of Exit: Feces, urine, wound drainage, respiratory secretions (if present), and contaminated hands of healthcare workers after patient contact.

Modes of Transmission: Primarily contact transmission, including direct contact with a colonized or infected patient or indirect contact through contaminated hands of healthcare workers, shared equipment (e.g., blood pressure cuffs, commodes, lifts), or environmental surfaces.

Portals of Entry: Urinary catheter insertion sites, surgical wounds, intravenous catheter sites, mucous membranes, or the gastrointestinal tract through contaminated hands or equipment.

Susceptible Host: Older adults, immunocompromised individuals, patients with chronic illnesses, those receiving frequent antibiotics, patients with invasive devices (e.g., Foley catheters, central lines), or individuals with open wounds.

A patient was admitted to our unit after being hospitalized for six months at another healthcare facility. As part of the admission screening process, the patient tested positive for CPO colonization. Although the patient did not have signs or symptoms of infection, they were placed on Contact Precautions because CPO can spread through direct or indirect contact. Healthcare workers were required to perform hand hygiene before and after patient contact, wear a gown and gloves when entering the room, dedicate equipment whenever possible, and thoroughly disinfect reusable equipment after each use. These measures helped prevent transmission of CPO to other vulnerable patients on the unit and demonstrated the importance of breaking the chain of transmission through consistent adherence to IPAC practices.

[Edna]

Example: Gastro Outbreak in a Long-Term Care Home

Infectious Agent: Norovirus (gastro virus)
Reservoir: Infected resident or staff member
Portal of Exit: Vomit or diarrhea
Mode of Transmission: Contaminated hands, shared equipment, or contaminated surfaces
Portal of Entry: Mouth (touching the mouth after touching contaminated hands or surfaces)
Susceptible Host: Elderly residents, especially those with weakened immune systems

This is a common example in long-term care and shows why hand hygiene, proper PPE, and cleaning are essential to stop the chain of infection.

[Katelyn]

Infectious Agent:
Scabies mite (Sarcoptes scabiei)

Reservoirs:
Infested patients (and occasionally contaminated bedding, clothing, or towels)

Portals of Exit:
Skin containing mites (direct skin-to-skin contact; mites can also be present on contaminated linens or clothing for a short time)

Modes of Transmission:
Prolonged direct skin-to-skin contact; less commonly through contaminated bedding, clothing, or towels

Portals of Entry:
Skin through direct contact with an infested person or contaminated items

Susceptible Host:
Anyone exposed, especially people living or working in close-contact settings such as hospitals or long-term care homes, and individuals with weakened immune systems

[Author]

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