Infection-control case
Safety gate · before any work
- Wear the required PPE, keep the bench clear, handle equipment only as directed, and know where the eyewash, sink, and spill kit are before you start.
- Human samples and data stay private: label with a code, never a name, and dispose of materials in the correct waste container, then wash your hands.
Do now
Students analyze a hospital scenario to identify breaks in the chain of infection and prescribe controls.
- Hand in
- Written analysis identifying the weakest chain-of-infection link in the scenario, naming the aseptic intervention, and stating one limitation.
- Where
- Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
You get two school days for every day you were absent, so this deadline moves with you.
Given one patient's immune status, the staff's habits, and the room's conditions, which one of those details is the weakest link letting infection through?
Students analyze a hospital scenario to identify breaks in the chain of infection and prescribe controls.
- • Identify a specific break in the chain of infection from the scenario.
- • Recommend a control measure and state one limitation.
- Name the correct order for hand hygiene and PPE: do you wash before gloving up, or after taking gloves off, or both?
- In a hospital scenario, name one detail about the patient and one detail about the staff that could each raise infection risk.
- 1Record the SOP for hand hygiene and PPE donning and doffing.
- 2Identify the variables in the scenario that raise or lower risk.
- 3Trace the chain of infection for one patient and locate the weakest link.
- 4Recommend a specific intervention that breaks that link.
- 5Document one limitation in your data or assumptions.
What did this day actually feel like?
Infection-control case
We analyzed a hospital scenario, traced the chain of infection for one patient, and found the weakest link.
The weakest link in my scenario was not the dramatic one. It was hand hygiene compliance between two routine tasks, not a procedure or a piece of equipment. The boring failure was the one that mattered, which I gather is usually true.
Turned in: written analysis → recorded in Class Records
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
The same day, drawn.
The weakest link in my scenario was not the dramatic one. It was hand hygiene between two routine tasks.
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
🛠 Get unstuck · pick your level
Lab day: Tier 1 is the whole class at the bench. No extension today.
🔑 Today's words · 5
Tap a word in the lesson for a plain meaning and one example. Recycled into next week's Do-Now.
Do the work · 80-minute blockfirst 5 min = hook▸
💡 Big idea: You must locate the single weakest link in a specific case before prescribing a control, because a targeted fix aimed at the real weak point works while a general hygiene tip cannot be tested or aimed.
- 0-8 minRecord the hand hygiene and PPE donning/doffing SOP in your notebook.
- 8-18 minRead the hospital scenario; identify variables that raise or lower risk.
- 18-40 minTrace the chain of infection for the case patient; mark the weakest link.
- 40-58 minWrite a specific intervention that breaks the weakest link, with chain-based reasoning.
- 58-70 minDocument one data limitation or assumption that could change the recommendation.
- 70-80 minShare chain finding with a partner; confirm you agree on which link is weakest.
- • You traced the chain of infection in notes yesterday; today you apply it to a real hospital scenario.
- • The SOP for PPE donning and doffing is a handling and preparation skill tested on WebXam 072110 strand 5.
- • Your recommendation must name the specific chain link it breaks, not just say 'wash hands more.'
- • One limitation is required: every control has a failure mode, and naming it is intellectual honesty.
- • Each variable in a hospital scenario (patient immune status, staff behavior, environment) maps to a specific chain link.
- • An effective infection-control recommendation names the exact link it targets, not just a general hygiene tip.
- • Data limitations reveal where the recommendation could fail if assumptions are wrong.
Unit 3.1 Nosocomial Nightmare: Hospital-acquired infections, chain of infection, pathogens, immune response, infection control. · Infection-control case
Day 3 of this lesson. Open this exact section in myPLTW (find it in Clever, Microsoft sign-in), then do the work below.
Do this: Open myPLTW and locate the Lesson 3.1 Nosocomial Nightmare infection-control case or scenario activity. Use the platform scenario to supplement or verify your scenario analysis.
Submit any platform prompts for this Lesson 3.1 activity before end of the period.
Platform prompts should be done by mid-period; the written recommendation is today's primary product.
Written recommendation with chain-link citation plus platform submission.
The official PLTW activity stays inside myPLTW. If myPLTW will not open, use F1 and E1-E3 on this page to complete today's local evidence decision, then make up the official activity when access returns. Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Check things off as you work, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible through the submission route shown below.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
Unit 3.1 Nosocomial Nightmare: Hospital-acquired infections, chain of infection, pathogens, immune response, infection control. · Infection-control case
Open myPLTW and locate the Lesson 3.1 Nosocomial Nightmare infection-control case or scenario activity. Use the platform scenario to supplement or verify your scenario analysis.
Platform prompts should be done by mid-period; the written recommendation is today's primary product.
This is how Mr. Mendoza sees the class keeping pace with PLTW. Be honest, it only helps if it is accurate.
🎯 Students analyze a hospital scenario to identify breaks in the chain of infection and prescribe controls.
- Record the SOP for hand hygiene and PPE donning and doffing.
- Identify the variables in the scenario that raise or lower risk.
- Trace the chain of infection for one patient and locate the weakest link.
- Recommend a specific intervention that breaks that link.
- Document one limitation in your data or assumptions.
Pre-lab: Written analysis identifying the weakest chain-of-infection link in the scenario, naming the intervention, and stating one limitation.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Use the checklist just below and upload by 11:29 PM for full credit. Absent with an excused absence? You get two school days for every day you were absent, so this deadline moves with you.
| Task | Who |
|---|---|
| Record the SOP for hand hygiene and PPE donning and doffing. | _______ |
| Identify the variables in the scenario that raise or lower risk. | _______ |
| Trace the chain of infection for one patient and locate the weakest link. | _______ |
| Recommend a specific intervention that breaks that link. | _______ |
| Document one limitation in your data or assumptions. | _______ |
Working solo? Put your own name in "Who" for every row.
- Identify a specific break in the chain of infection from the scenario.
- Recommend a control measure and state one limitation.
- 1Do thisStudents analyze a hospital scenario to identify breaks in the chain of infection and prescribe controls.
- 2Use this resource
- 3Submit thisPre-lab: Written analysis identifying the weakest chain-of-infection link in the scenario, naming the aseptic intervention, and stating one limitation.
- 4Submit it here
- 1Open the drop folder.
- 2Sign in with your district Microsoft account, not a personal one.
- 3Upload the file, named Lastname_Firstname__Assignment Title.
- 4Your own upload panel says Uploaded with a green check: that is your receipt.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Principles of Biomedical Technology (Principles of Biomedical Science) › Unit 3.1 Nosocomial Nightmare: Hospital-acquired infections, chain of infection, pathogens, immune response, infection control. › Pre-labOpen the drop folder
Learn it · deck, reading, and vocabulary▸
The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.
Generated from this lesson's canonical data with a red-team citation check.
Infection spreads through six ordered links, so breaking any single link stops because the germ can no longer complete its path to a new host.
You must locate the single weakest link in a specific case before prescribing a control, because a targeted fix aimed at the real weak point works while a general hygiene tip cannot be tested or aimed.
Wet footprints appear across connected rooms after one person enters from the rain.
- Which footprint came first?
- Which rooms connect?
- What pattern would support more than one entry point?
Patterns across time and connection can narrow a explanation without proving it by themselves.
People change behavior, infections have periods, and surveillance data can be incomplete.
- • Footprints map to recorded cases.
- • Room connections map to exposures.
- • The route hypothesis maps to a limited claim.
Driving question: Given one patient's immune status, the staff's habits, and the room's conditions, which one of those details is the weakest link letting infection through?
What you already know: Infection spreads through six ordered links, so breaking any single link stops because the germ can no longer complete its path to a new host.
New idea: You must locate the single weakest link in a specific case before prescribing a control, because a targeted fix aimed at the real weak point works while a general hygiene tip cannot be tested or aimed.
Visual or model: F1. F1. A lesson illustration or teaching diagram for Infection-control case. Use it with E1-E3; it is a model or context image, not experimental or patient data. What to notice: Trace the labeled observation or evidence sequence before choosing an explanation.
- Observe or measure the relevant feature in Infection-control case.
- Organize the observation with a stable evidence ID.
- Apply this rule: Patterns across time and connection can narrow a explanation without proving it by themselves.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: Given one patient's immune status, the staff's habits, and the room's conditions, which one of those details is the weakest link letting infection through?
What the evidence supports: E1-E3 and F1 support the daily take-home when the response meets the stated success criteria.
What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.
- • nosocomial: Describes an infection that a patient catches while in a hospital or healthcare setting rather than bringing it in from outside.
- • : A microorganism such as a bacterium, virus, fungus, or parasite that can cause disease in its host.
- • vector: A that delivers genetic material into a cell, such as a or virus, or an organism like a mosquito that spreads a disease.
- • reservoir: A living host or environment where a normally lives and multiplies, serving as the source from which infections spread.
- • : The passing of a disease-causing agent from one host to another, by routes such as contact, droplets, contaminated objects, or vectors.
- • : The body's coordinated defense against a harmful invader, in which immune cells recognize, attack, and remember the threat.
- • PPE: Personal protective equipment, the gear like gloves, goggles, lab coats, and masks worn to shield the body from chemical, biological, or physical hazards.
- • : Describing techniques that keep an area free of harmful microbes so cultures and patients are not contaminated.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice.
Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.
Each variable in a hospital scenario (patient immune status, staff behavior, environment) maps to a specific chain link.
Limit: E1 supplies context or an observation; it does not by itself establish the explanation.
You must locate the single weakest link in a specific case before prescribing a control, because a targeted fix aimed at the real weak point works while a general hygiene tip cannot be tested or aimed.
Limit: E2 is a teaching statement or comparison and must be checked against the task evidence.
Identify a specific break in the chain of infection from the scenario.
Limit: E3 supports only the result or product criterion named here; it cannot justify a broader clinical or causal claim.
PLTW-PBT-2026-11-12 · Simulated classroom evidence scenario
Your role: biomedical investigator
Decision: Your team must decide what the evidence from Infection-control case supports before submitting the pre-lab readiness record named on the lesson page.
- • Choose the strongest supported explanation.
- • Choose the next evidence to collect.
- • Hold the decision because the evidence is insufficient.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the pre-lab readiness record.
Claim ceiling: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about Infection-control case. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
Reason for review: Your team must decide what the evidence from Infection-control case supports before submitting the pre-lab readiness record named on the lesson page.
Context: Good infection control is targeted, not general: you diagnose the specific weak link in a specific situation before you prescribe a fix.
- • T1: Record the SOP for hand hygiene and PPE donning and doffing.
- • T2: Identify the variables in the scenario that raise or lower risk.
- • T3: Trace the chain of infection for one patient and locate the weakest link.
- • T4: Recommend a specific intervention that breaks that link.
- • T5: Document one limitation in your data or assumptions.
- • E1: Each variable in a hospital scenario (patient immune status, staff behavior, environment) maps to a specific chain link.
- • E2: You must locate the single weakest link in a specific case before prescribing a control, because a targeted fix aimed at the real weak point works while a general hygiene tip cannot be tested or aimed.
- • E3: Identify a specific break in the chain of infection from the scenario.
Measurements: Use only the measurements, units, graph, or counts supplied in today's task. No additional patient measurement is implied.
Figure finding: Teaching diagram for Infection-control case. Trace the labeled observation or evidence sequence before choosing an explanation. This is a teaching model, not patient or experimental data.
Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.
Rate or percent = part / comparison total x 100%. Percent change = (new - comparison) / comparison x 100%.
If 18 of 60 records meet a condition, the frequency is 18 / 60 x 100% = 30%.
Name the comparison total. A percent describes the supplied group and does not automatically predict an individual's outcome.
Use today's supplied counts to calculate one rate, risk, frequency, or percent change. Show the denominator and interpretation.
- • The solution must address the stated need in Infection-control case.
- • The decision must be supported by E1-E3.
- • The final product must make the success criteria visible.
- • Complete the work inside the 80-minute block.
- • Use only supplied or teacher-approved materials and evidence.
- • Do not trade , accessibility, or privacy for speed.
- • and evidence quality: must pass before scoring other criteria.
- • User need and effectiveness: highest scored criterion.
- • Time, cost, and ease of use: compare only after and effectiveness pass.
Test evidence: For each option, record the E1-E3 result that supports or fails each criterion. Do not assign a score without a named observation.
- Version or option tested
- Criterion met or missed
- Evidence ID and result
- Revision made
- Reason for the revision
- Need and user
- Criteria and constraints
- Chosen option and evidence
- Test result
- Revision and reason
Students often think Students think a good recommendation is to improve hygiene everywhere in the scenario at once.. The trap: A recommendation that targets everything targets nothing, because you cannot tell if it worked or where to spend limited time and money. A strong control names the exact link it breaks, so the fix is testable and the weakest point actually gets closed.
Scenario summary: Patient A is recovering from abdominal surgery in a shared room. A staff member moved between Patient A and a patient with a draining wound without changing gloves. Patient A is on a medication that lowers immune function.
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, doff them before leaving the bedside, then sanitize again.
Risk variables I identified:
- Patient immune status: lowered, which raises susceptibility.
- Staff behavior: gloves not changed between patients, which raises transmission risk.
- Environment: shared room with a draining-wound patient nearby, which raises exposure.
Chain trace for Patient A:
- Agent: wound bacteria from the neighboring patient.
- Reservoir: the draining wound.
- Portal of exit: wound drainage on the staff member's gloves.
- Mode of transmission: contaminated gloves carried to Patient A.
- Portal of entry: Patient A's surgical incision.
- Susceptible host: Patient A, immune-suppressed.
Weakest link: the mode of transmission, because the same gloves carried bacteria directly from one patient to another.
Recommended intervention: enforce glove change plus hand hygiene between every patient. This breaks the transmission link before bacteria can reach Patient A's incision.
Limitation: I assumed the neighboring wound is the source. If Patient A's own skin flora caused the infection, the glove-change rule would not be the highest-priority fix.
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 on the class site, or hand it to Mr. Mendoza in class.
- CER:
- Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
- SOP:
- Standard Operating Procedure, the exact steps to follow (especially in a lab).
- Tracker:
- Your PLTW progress log where you record completed evidence.
- myPLTW:
- The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
Tap the speaker to hear a term. Add two of these to your notebook glossary with a definition and an example in your own words.
Pick just 2 or 3 words from today and make them yours: write what each one means in your own words, name the context clue or evidence that helped, then give one example from what you actually did in Infection-control case. Try your own words first; the glossary is there if you get stuck. This is voluntary and counts as extra credit, so keep it short.
Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.
Hand-picked readings and interactives for this lesson, from authoritative open organizations and PLTW's own public course outline.
Check yourself · commit, then reveal▸
Claim ceiling for this check: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about Infection-control case. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
A chemotherapy patient (very low white-blood-cell count) is on a unit with good handwashing but a reused, poorly cleaned blood-pressure cuff moving room to room. Which link is the weakest here, and what single control targets it?
Write an answer and pick a confidence to unlock the key.
Fast retrieval with instant answers, not the commit-then-reveal check above. Try each from memory first: write what you remember about the earlier units, then check yourself here.
Go further and get help▸
I can name the procedure's purpose and the evidence I will record. I can identify each named hazard and the control that reduces it: Wear the required PPE, keep the bench clear, handle equipment only as directed, and know where the eyewash, sink, and spill kit are before you start. My data table is ready before materials are handled.
Finish the checklist before you handle any material.
- • Wear the required PPE, keep the bench clear, handle equipment only as directed, and know where the eyewash, sink, and spill kit are before you start.
- • Human samples and data stay private: label with a code, never a name, and dispose of materials in the correct waste container, then wash your hands.
- 1Before materials are handled, identify the purpose, variables or comparison, controls, measurement units, and stop-work condition.
- 2Record the SOP for hand hygiene and PPE donning and doffing.
- 3Identify the variables in the scenario that raise or lower transmission risk.
- 4Trace the chain of infection for one patient and locate the weakest link.
- 5Recommend a specific aseptic intervention that breaks that link.
- 6Document one limitation in your data or assumptions.
- 7Record each result in the prepared table before interpreting it. Mark missing, repeated, or invalid results truthfully.
- 8Complete the named cleanup and waste route, remove PPE safely, wash hands when required, and confirm the station is ready for the next group.
| Trial or sample ID | Independent condition | Measured result with units | Observation before interpretation | Quality-control note |
|---|---|---|---|---|
Before the procedure, predict the result and cite the rule behind the prediction.
After the procedure, compare the result with the prediction and name one limitation or source of uncertainty.
What today's skills lead to. These are real health-science careers this course builds toward. Tap one to see, on the US Department of Labor's O*NET site, what the job actually involves, what it pays, and how fast it is growing.
Today is individual work you can do from home: complete the same target above, then submit your Pre-lab.
Open the drop folderTurn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Class still runs. Complete the online activity above (it's self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
CDC: infection control basics and the chain of infectionYou've passed Unit 2, so the optional extra-credit track is open. Complete reserved-unit work from home, including virtual labs, for extra credit. Each item shows its correct submission route.
Open the extra-credit track- CompleteEvery required part of the artifact is present, nothing left blank.
- AccurateThe science and the data are correct and match the evidence.
- Scientific reasoningYou explain your claim with evidence and reasoning (CER), not just an answer.
- Professional communicationClear, organized, labeled, and written the way a clinician or scientist would.
- SubmittedTurned in the right way, on the class site or handed to Mr. Mendoza in class, and confirmed. Not in Schoology: that is where the report-card grade appears later.
- Error analysis and method · counts doubleName a specific limit of the method and how it moved your result, and compare what you predicted to what happened. "Human error" does not count; say what about the procedure or instrument caused it.