Infection-control case
Wed, Nov 18, 2026 · Week 13 · Principles of Biomedical Technology (Principles of Biomedical Science)
Today's goal: Students analyze a practice hospital scenario to identify breaks in the chain of infection and prescribe controls.
This is a model of the work you should turn in today. Use it to check your own: match the structure and the level of detail, do not copy it. Your data and wording should be your own.
Parallel case, not today's scenario: on a respiratory unit, two patients on nebulizer treatments develop the same lung infection with a water-loving bacterium. The nebulizer cups were refilled from a tap and reused across a shift.
SOP I recorded for hand hygiene and PPE:
- Wash or sanitize hands before and after every patient contact.
- Don gloves and gown before touching a wound or a device that enters the body, doff them before leaving the bedside, then sanitize again.
Risk variables I identified:
- Patient status: damaged lungs, which raises susceptibility.
- Staff behavior: cups refilled from a tap and reused, which creates a source.
- Environment: one reusable cup serving several patients, which links them.
Chain trace for the second patient:
- Agent: the water-loving bacterium.
- Reservoir: standing tap water in the reused nebulizer cup.
- Portal of exit: the mist leaving the cup.
- Mode of transmission: the aerosol carried into the airway (indirect, through a vehicle).
- Portal of entry: the airway.
- Susceptible host: a patient with damaged lungs.
Weakest link: the reservoir. Every other link in this chain depends on water standing in a reused cup; remove that and there is nothing to carry.
Recommended intervention: sterile water only, one cup per patient, replaced on the schedule the SOP sets, with the change logged. This closes the reservoir before an aerosol forms.
Limitation: I assumed the cups were the shared source. A culture of the water would confirm it; if the two infections came from separate sources, the fix still helps but is not the answer to this outbreak.
How to use this: today's scenario is not this one. Trace the surgical patient's chain the same way, and let the link with the most risk factors on it be the one you name.
This model shows the level of evidence and organization needed to complete: Completes the infection-control case prep: a written analysis that traces the chain of infection for one patient, names the weakest link, prescribes one aseptic intervention, and states a limitation.
- Identify the purpose, hazards, and required controls.
- Write the procedure in a usable order.
- Confirm materials, measurements, and waste handling before starting.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Also due today: Submit your written case analysis in Schoology.
Turn in: Written analysis identifying the weakest chain-of-infection link in the scenario, naming the aseptic intervention, and stating one limitation.
Go to Schoology to turn this in.
Submit one PDF. Schoology attaches your name to your upload; on the page itself, write your period and code. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf.
Open Schoology PDF upload helpIf you cannot get in, see Mr. Mendoza. Do not skip the work.
Claim ceiling: Today's evidence supports a classroom claim about infection-control case. It cannot prove causation, diagnose a real patient, or justify action outside this room.
One exam-style question that uses exactly what you practiced today. Try it before you reveal the answer, then read why each choice is right or wrong.
Tap an answer to see the full explanation. Nothing is recorded or graded.
It builds this reusable test skill: Identifying the weakest chain-of-infection link in a clinical scenario.
- Name the concept or data pattern being tested.
- Cross out choices that violate that rule or the evidence.
- Justify the best remaining choice before checking the answer.