[Grace]

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:

[Mildred]

Chain of Transmission – Medical–Surgical Unit

Infectious Agent:
Clostridioides difficile (C. difficile)

Reservoirs:

Gastrointestinal tract of infected or colonized patients

Contaminated surfaces (bed rails, call bells, toilets, commodes)

Contaminated healthcare workers’ hands

Portals of Exit:

Feces from an infected or colonized patient (during bowel movements or incontinence episodes)

Modes of Transmission:

Indirect contact transmission via the contaminated hands of healthcare workers

Contact with contaminated equipment or environmental surfaces (e.g., shared commodes, improperly cleaned rooms)

[Arlene]

Hi Mildred

C-Diff must be one of my most feared infections as it is so difficult to remove/treat increasing the chance of transmission.

Lack of education – Not all health care providers are aware that alcohol-based hand rub (ABHR) is not an effective way to remove C-Diff from hands therefore soap and water must be used.

Accessible facilities – Many times, the inconvenient placement of sinks within facilities prevent the accessibility of soap and water hand washing as frequently as needed.

Your document seems to have cut off “Portals of Entry” (fecal-oral) and “Susceptible Host” (immunocompromised, previous antibiotic use).

[Carla-Jane]

Chain of Transmission; Long Term Care Facility

Infectious Agent : Norovirus

Reservoirs: Infected residents, Contaminated surfaces, Contaminated food or water

Portals of exit: Vomit, Feces, Respiratory droplets. The virus exits the body primarily through gastrointestinal secretions.

Mode of Transmission: Direct contact – hands of healthcare workers or residents after toileting.
Indirect contact – touching contaminated surfaces or shared equipment.
Fecal-oral transmission – Ingestion of virus particles due to poor hand hygiene

Portal of Entry: Mucous membranes (mouth or nose), Ingestion of contaminated food or hands

Susceptible Host: Older adults with weakened immune systems, residents with chronic illness

[Jasvir]

I like your example because norovirus is really common in long-term care and spreads very fast. It shows how even small things, like missing hand hygiene after toileting residents or touching shared equipment, can quickly affect many residents. The part about older adults being more vulnerable also stood out to me. It’s a good reminder of why infection control is so vital in LTC, not just for policy, but for real people’s safety.

[Mujidat]

This is a very clear and well-organized example of the chain of transmission, and norovirus is especially relevant in long-term care settings. You accurately identified infected residents and contaminated surfaces as key reservoirs, which reflects how easily norovirus can persist and spread in shared environments.

I also like how you clearly explained the fecal-oral route and connected it to poor hand hygiene after toileting, as this is one of the most common ways norovirus outbreaks occur in LTC facilities. Your inclusion of both direct and indirect contact highlights the importance of environmental cleaning and proper hand hygiene for staff and residents

[Arlene]

Chain of Transmission – Psychiatric ICU

Infectious Agent: MRSA

Reservoirs-
High touch surfaces (shared bathrooms, door handles), Nasal passages, medical equipment, linens, skin of infected or colonized individuals, contaminated hands of healthcare workers.

Portals of Exit-
Respiratory secretions, wound drainage, Skin of colonized or infected individuals

Modes of Transmission-
Direct: Healthcare workers hands; contact with skin or respiratory secretions of an infected or colonized individual;
Indirect: Medical equipment (Vitals machines); door handles; linens; healthcare workers clothing

Portal of Entry –
Break in skin (open wounds), invasive devices (Peripheral/central lines), mucous membranes (nasal passages, mouth)

Susceptible Host-
Immunocompromised individuals; Patients with invasive medical devices; open wounds

[Aleena Mary]

Chain Of Transmission- MRSA in Hospital .

Infectious Agent: MRSA Bacteria.

Reservoirs: Patients who are colonized or infected, Healthcare workers’ hands or clothing,Contaminated medical equipment (bed rails, IV pumps).

Portals of Exit: Open wounds or surgical sites,Respiratory secretions, Skin flakes.

Modes of Transmission: Direct contact: touching the infected patient
Indirect contact: touching contaminated surfaces or instruments

Portals of Entry: Breaks in the skin, mucous membranes.

Susceptible Host: Patients with weakened immunity, Elderly, infants, or those recovering from surgery, Anyone with chronic illnesses or open wounds

[Jasvir]

Chain of Transmission -Community Care

Simple things like hand hygiene, cleaning equipment, and using PPE properly really matter because, in my experience, respiratory infections such as the flu or COVID-19 are common in home care. Here is an example of the chain of transmission in this setting:

Infectious Agent: Influenza or COVID 19 virus
Reservoirs: Client or family members in the home
Portals of Exit: Coughing, sneezing, talking
Modes of Transmission: Droplets, hands, shared surfaces/equipment
Portals of Entry: Nose, mouth, eyes
Susceptible Host: Older adults, clients with chronic illness or immunocompromised, and caregivers

[Mujidat]

Practice Area: Long-Term Care Facility

Infectious Agent:
Respiratory Syncytial Virus (RSV)

Reservoirs:
Infected residents, staff, or visitors carrying RSV; contaminated surfaces such as bed rails, call bells, wheelchairs, and shared equipment

Portals of Exit:
Respiratory secretions are released through coughing, sneezing, talking, or nasal drainage
Modes of Transmission:

Direct contact with infected respiratory secretions
Droplet transmission during close contact
Indirect contact via contaminated hands, clothing, or environmental surfaces

Portals of Entry:
Mucous membranes of the nose, mouth, or eyes

Susceptible Host:
Older adults, residents with chronic lung or heart disease, immunocompromised individuals, and those living in close-contact environments

[Mebo]

Hello Mujidat
Thank you for sharing RSV in Long term Care, and I agree is huge significant concern in Long term care setting from experiencing
working in LTC for over 5 years, and from infection- control perspective, rapid implementation of Droplet and conta precautions is
very essential once an outbreak is declared. Most Importantly hand hygiene remain one of the most effective intervention, environment
cleaning espeacially high touch areas.

[Mebo]

Hospital Acute Care- CPO (Carbapenemase- producing Organisms
Infectious Agent: Escherichia coli, Enterobacter spp
Reservoirs: colonized or infected patients – GI tract, wounds, respiratory tract
Portals of Exit: feces (most common), wound drainage, urine
Modes of Transmission: direct or indirect contact- health care workers hands touching infected patients body fluids, shared patient rooms or bathrooms
Portals of Entry: Hands touching mucous membranes (eyes, nose, mouth)
Susceptible Host: Elderly or immunocompromised patients, ICU patients, Patients on broad – spectrum antibiotics

[James]

Chain of transmission: Long-term Care
Infectious Agent: Covid-19
Reservoirs:
Human respiratory tract, contaminated surfaces, health care workers
Portals of Exit:
Respiratory secretions from the nose and mouth whether it be from coughing, sneezing or talking.
Modes of Transmission:
Respiratory droplets
Indirect contact via contaminated surfaces
Portals of Entry:
Mucous membranes of the eyes, nose and mouth, respiratory tract
Susceptible Hosts:
Individuals not naturally immune to the virus, the elderly, people with autoimmune disorders and chronic illnesses, as well as people who haven’t been vaccinated.

[Adetola]

Great example of the chain of transmission in a long-term care setting. You clearly identified COVID-19 as the infectious agent and accurately linked the human respiratory tract and contaminated surfaces as key reservoirs. I also like how you highlighted multiple portals of exit and entry, which reflects how easily COVID-19 can spread in shared living environments. Identifying elderly residents and those with chronic or autoimmune conditions as susceptible hosts is especially relevant in long-term care, where residents are at higher risk for severe illness. Overall, your examples clearly show why strict infection-prevention measures are essential in this setting.

[Adetola]

Chain of Transmission – Long-Term Care (C. difficile)

Infectious Agent:
Clostridioides difficile

Reservoirs:
Infected or colonized residents; contaminated surfaces such as toilets, bed rails, commodes, and shared equipment

Portals of Exit:
Feces from residents experiencing diarrhea

Modes of Transmission:
Indirect contact through contaminated hands of staff or contaminated surfaces and equipment

Portals of Entry:
Mouth (ingestion of spores via hands or objects)

Susceptible Hosts:
Older adults in long-term care, residents on antibiotics, and those with weakened immune systems

[Author]

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