For information and reference only – not to be submitted as your own work.
This model answer shows how a strong response to the STE404 Assessment 2 question on microbial resistance, Spaulding classification and tikanga Māori can be organised. It is an extract written for a sterile services setting in Aotearoa New Zealand, and it is paired with our step-by-step guide to planning the answer. Use it to understand structure, depth and referencing, then build your own response from your workplace practice and course materials.
Planning table
| Task | What the marker looks for | Suggested words (illustrative) |
|---|---|---|
| 1(a) and 1(b) Resistance hierarchy | Correct order, correct terminology, one organism and one infection per level, at least one blood-borne virus | 200 |
| 2 Spaulding classification | Critical, semi-critical and non-critical examples from your own unit, with the reprocessing level each requires | 150 |
| 3 Spores versus viruses | Structural contrast, then why sterilisation is non-negotiable for spore-contaminated items | 150 |
| Task 2 Q1 Floor contamination | Infection control reasoning and tikanga reasoning, kept distinct | 150 |
| Task 2 Q2 Professional response | Calm, private, respectful, evidence-based conversation, followed by escalation only if needed | 150 |
| Task 2 Q3 Tapu, noa and te Tiriti | A clear link to partnership, participation and protection, plus one practical team-wide change | 200 |
Task 1: Infection control and blood-borne diseases
1(a) Hierarchy of microbial resistance
Microorganisms differ in how well they tolerate disinfectants and sterilising agents, and the usual teaching hierarchy ranks them from most to least resistant (Rutala & Weber, 2019). Reading from the least resistant upward, the order is: lipid-enveloped (medium-sized) viruses, vegetative bacteria, fungi, non-enveloped (small) viruses, mycobacteria, coccidia, bacterial spores and, at the top, prions. McDonnell and Russell (1999) describe the same descending pattern of resistance and explain that structure explains much of it: an outer lipid envelope or a thin cell wall leaves a microbe vulnerable, while a mycobacterial waxy wall, a spore coat or an abnormally folded protein protects it.
1(b) Examples and infections
| Level (least to most resistant) | Example organism | Infection it can cause |
|---|---|---|
| Lipid-enveloped viruses | Hepatitis B virus (blood-borne); also HIV and hepatitis C virus | Hepatitis B, which can lead to chronic liver disease |
| Vegetative bacteria | Staphylococcus aureus | Surgical site and wound infection |
| Fungi | Candida albicans | Candidaemia and mucosal infection |
| Non-enveloped (small) viruses | Poliovirus or hepatitis A virus | Poliomyelitis or hepatitis A |
| Mycobacteria | Mycobacterium tuberculosis | Tuberculosis |
| Coccidia | Cryptosporidium | Diarrhoeal illness |
| Bacterial spores | Clostridioides difficile or Clostridium tetani | Antibiotic-associated colitis or tetanus |
| Prions | The agent of Creutzfeldt–Jakob disease | A fatal neurodegenerative disease |
This answers the colleague’s question. Hepatitis B, hepatitis C and HIV sit at the low-resistance end because they are lipid-enveloped, so well-managed high-level disinfection can inactivate them. Hepatitis B virus is nonetheless unusually stable in the environment and can remain infectious on surfaces for at least seven days (Schillie et al., 2018), which is why items must be cleaned thoroughly before any disinfection step. Organisms higher in the hierarchy tolerate disinfectants and therefore need sterilisation.
2 Spaulding’s classification
Spaulding (1968) proposed grouping reusable devices by the risk of infection from the way they are used, and this scheme still underpins reprocessing policy (Rutala & Weber, 2019). The category sets the minimum level of processing needed to prevent transmission, including transmission of blood-borne viruses.
| Category | Contact | Example items (illustrative) | Minimum reprocessing |
|---|---|---|---|
| Critical | Enters sterile tissue or the vascular system | Scalpel handles, forceps, orthopaedic instruments | Cleaning, then sterilisation |
| Semi-critical | Contacts mucous membranes or non-intact skin | Flexible endoscopes, anaesthetic breathing equipment | Cleaning, then high-level disinfection (sterilisation where the device allows) |
| Non-critical | Contacts intact skin only | Blood pressure cuffs, instrument trolleys | Cleaning with low- or intermediate-level disinfection |
In practice, every category begins with cleaning, because organic soil shields microbes and blocks the disinfectant or steam. A critical item contaminated with blood must be sterilised because the virus has a direct route into sterile tissue. A semi-critical item meets mucosa, so high-level disinfection is the floor. A non-critical item touches intact skin, so cleaning and low-level disinfection are sufficient. Choosing the correct level, and keeping used and processed items apart, interrupts the chain of infection at the point where an infectious agent could otherwise reach a susceptible host through a contaminated device. In New Zealand, reprocessing requirements are now set out in AS/NZS 5369:2023, which superseded AS/NZS 4187:2014 (Standards New Zealand, 2023).
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3(a) Spores compared with viruses
A virus is a small particle of nucleic acid in a protein capsid, sometimes with a lipid envelope, and it cannot metabolise or replicate outside a host cell. Enveloped viruses are fragile because detergents, alcohols and heat disrupt the lipid layer. A bacterial spore is a dormant, dehydrated cell formed by genera such as Bacillus and Clostridium. It has a core with protected DNA, a thick cortex and a multilayered protein coat, which together resist heat, desiccation, many chemicals and radiation (McDonnell & Russell, 1999). Consequently, a process that quickly inactivates a lipid-enveloped virus may leave spores viable.
3(b) Why spore-contaminated instruments must be sterilised
Spores can survive disinfectants that kill vegetative bacteria and enveloped viruses, and they germinate into active bacteria when conditions allow (Rutala & Weber, 2019). If a spore-contaminated critical item is only disinfected, viable spores could be placed directly into sterile tissue and cause infection such as tetanus or gas gangrene. Sterilisation, normally by validated steam under pressure, is designed to destroy all microbial life including spores, which is why spore tests are used to monitor sterilisers. Blood-borne viruses may be inactivated by disinfection, but a unit cannot reliably know in advance which contaminants an instrument carries, so critical items are sterilised every time.
Task 2: Infection control and cultural awareness
1 Why placing instruments on the floor is unsafe
(a) Infection control. The floor is heavily contaminated with soil and microbes, and dropping used instruments there can transfer organisms to the items, to footwear and hands, and onto trolleys or sinks. It also spreads blood and tissue residue across a clean working area, which creates exposure and sharps-injury risks for staff who later clean the floor or handle the load. Using a designated, contained transport tray avoids this. (b) Tikanga Māori. In tikanga, contaminated items that have been in contact with body-related matter are regarded as tapu and are kept separate from places associated with food and from everyday surfaces that are noa. Placing them on the floor disregards that separation and can cause cultural harm to colleagues and, indirectly, to the whānau whose care the instruments relate to. Cultural safety is judged by the person receiving care or working alongside you, not by the practitioner’s intent (Curtis et al., 2019), so I would avoid assuming my view of what is appropriate is sufficient.
2 Responding professionally to the colleague
I would speak to the colleague privately and promptly, and begin with a neutral, respectful observation: “I noticed the instruments were put on the floor while we moved the load. Can we talk through it?” I would explain the infection control concern first, using the unit procedure and the Spaulding principle that contaminated items must stay contained until cleaned. I would then explain that the placement also conflicts with tikanga, and I would ask what the colleague understood, since the aim is learning and not blame. I would offer practical alternatives such as a lidded transport trolley or a clearly marked tray at each sink. I would check that the instruments were re-cleaned and reprocessed if they were contaminated, and that the floor was cleaned and the event recorded through the unit’s incident process. If the behaviour recurred, I would inform the supervisor. Where the colleague is unsure about tikanga, I would suggest speaking with the organisation’s Māori health or cultural support contacts rather than offering my own interpretation as authoritative.
3(a) Tapu, noa and te Tiriti o Waitangi
Applying tapu and noa in a sterilising workflow lines up with the one-way flow from dirty to clean, and it supports te Tiriti principles as they are used in health. Partnership is shown when the unit works with Māori staff and advisers to decide how workflows, zoning and signage reflect tikanga (Ministry of Health, n.d.). Participation is supported when Māori staff and whānau views influence decisions that affect them, in line with the expectation that the health sector gives Māori opportunities to take part in decisions (Nursing Council of New Zealand, 2023). Protection is met when the unit actively protects Māori health and wellbeing, both by preventing infection and by protecting cultural values from being undermined through unsafe handling (Nursing Council of New Zealand, 2023). Practising in this way treats infection prevention and cultural safety as one commitment instead of two competing demands.
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3(b) One practical team-wide improvement
I would propose a clearly marked, lidded “contaminated transfer” trolley system with colour-coded trays and floor markings for the dirty-to-clean route, introduced through a short team briefing and a checklist that is audited monthly. Reviewing this with Māori health advisers before rollout would make the change collaborative, and a quick spot-check after three months would show whether floor placement incidents fell. Unit design also matters: placing handling and transfer points where staff do not need to set items down removes the temptation in the first place.
For more material on health and sterilising coursework, see our sterilizing technology assignment sample, our Māori health assignment help page and our do my assignment service. If you are working on the companion assessment, our STE404 Assessment 1 question page sets out its separate requirements.
References
Curtis, E., Jones, R., Tipene-Leach, D., Walker, C., Loring, B., Paine, S.-J., & Reid, P. (2019). Why cultural safety rather than cultural competency is required to achieve health equity: A literature review and recommended definition. International Journal for Equity in Health, 18, Article 174. https://doi.org/10.1186/s12939-019-1082-3
McDonnell, G., & Russell, A. D. (1999). Antiseptics and disinfectants: Activity, action, and resistance. Clinical Microbiology Reviews, 12(1), 147–179. https://doi.org/10.1128/CMR.12.1.147
Ministry of Health. (n.d.). Te Tiriti o Waitangi framework. Manatū Hauora. https://www.health.govt.nz/maori-health/te-tiriti-o-waitangi-framework
Nursing Council of New Zealand. (2023). Te Tiriti o Waitangi policy statement. https://nursingcouncil.org.nz/Public/NCNZ/About-section/Te_Tiriti_o_Waitangi_Policy_Statement.aspx
Rutala, W. A., & Weber, D. J. (2019). Guideline for disinfection and sterilization in healthcare facilities, 2008: Update May 2019. Centers for Disease Control and Prevention. https://stacks.cdc.gov/view/cdc/134910
Schillie, S., Vellozzi, C., Reingold, A., Harris, A., Haber, P., Ward, J. W., & Nelson, N. P. (2018). Prevention of hepatitis B virus infection in the United States: Recommendations of the Advisory Committee on Immunization Practices. MMWR Recommendations and Reports, 67(1), 1–31. https://www.cdc.gov/mmwr/volumes/67/rr/rr6701a1.htm
Spaulding, E. H. (1968). Chemical disinfection of medical and surgical materials. In C. A. Lawrence & S. S. Block (Eds.), Disinfection, sterilization, and preservation (pp. 517–531). Lea & Febiger.
Standards New Zealand. (2023). AS/NZS 5369:2023 Reprocessing of reusable medical devices and other devices in health and non-health related facilities. https://www.standards.govt.nz/shop/ASNZS-53692023
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