Jun 9
Loeb vs McGeer Criteria in Aged Care: Understanding the Difference
How to Use Each Tool Correctly to Reduce Antibiotic Overuse in Australia and New Zealand
This blog explains the difference between the Loeb Minimum Criteria and the Revised McGeer Criteria — two essential tools for infection management in aged care. Discover which tool your nursing team should use at the bedside, which belongs in your IPC surveillance program, and why confusing the two is contributing to antibiotic overuse across Australian and New Zealand residential aged care facilities.
Antibiotic overuse in aged care in Australia and New Zealand is stark. The Australian
Commission on Safety and Quality in Health Care (ACSQHC) confirmed in August 2025 that
antimicrobial use is growing faster in aged care homes than anywhere else in the
community. Almost 1 in 5 prescriptions in residential aged care are written on a "when
required" basis, and successive Aged Care National Antimicrobial Prescribing Surveys show
that antibiotics are regularly prescribed for conditions that don't warrant them.
Two clinical tools sit at the centre of this conversation: the “Loeb Minimum Criteria” and the “Revised McGeer Criteria”. If you've heard both names but weren't sure which applies to which, you're not alone.
Loeb and McGeer serve different phases of infection management in your facility.
This is the most important message for your team.
- Loeb informs clinical care decisions, helping your nursing team and prescribers respond appropriately when a resident deteriorates
- McGeer informs your IPC program; helping your IPC Lead track infection trends, report to
your governing body, and meet your regulatory obligations
Dr Mark Loeb
Dr Allison McGeer
The one-line summary: Loeb is for the nurse at 10 pm. McGeer is for the IPC Lead on Monday morning.
What Are the Loeb Criteria?
The Loeb Minimum Criteria were developed by Dr Mark Loeb and a consensus panel of
experts and published in 2001. They were designed for one specific purpose: to help
clinicians decide whether to start antibiotics for a residential aged care resident, often
before test results are available.
Think of Loeb as your bedside decision-making guide. It leans towards caution,
recommending empiric treatment when there is a high likelihood of infection, even before a
diagnosis is confirmed.
Loeb covers four clinical syndromes:
Loeb covers four clinical syndromes:
- Suspected urinary tract infection (UTI), with and without an indwelling catheter
- Lower respiratory tract infection
- Skin and soft tissue infection
- Fever of unknown origin
The criteria rely entirely on signs and symptoms your nursing team can observe and document now, with no laboratory results required.
What Are the McGeer Criteria?
The McGeer Criteria were introduced in 1991 by Dr Allison McGeer and colleagues and were
extensively updated in 2012 by the Society for Healthcare Epidemiology of America (SHEA).
They are a surveillance tool used to consistently define and track true infections within a
facility over time.
McGeer is your IPC Lead’s surveillance tool. It helps quantify infections, estimate prevalence, identify trends, and benchmark your facility against others.
McGeer (2012 revision) covers:
McGeer is your IPC Lead’s surveillance tool. It helps quantify infections, estimate prevalence, identify trends, and benchmark your facility against others.
McGeer (2012 revision) covers:
- UTIs - with and without catheter
- Respiratory tract infections (including pneumonia and influenza-like illness)
- Skin, soft tissue, and mucosal infections
- Gastrointestinal infections - including norovirus and Clostridioides difficile (both added in the 2012 revision)
- Systemic infections
Unlike Loeb, McGeer requires clinical data, laboratory results, microbiology cultures, and imaging where relevant; information that is often only available days after a resident first shows signs of infection.
The Key Difference at a Glance
This table is the most important information to share with your team.
How Loeb and McGeer differ in purpose, timing, and data requirements
How Loeb and McGeer differ in purpose, timing, and data requirements
| Aspect | Loeb Criteria | McGeer Criteria |
| Primary purpose | Guide decisions about starting antibiotics | Define and track infections for surveillance |
| When used | At the point of clinical assessment (real-time) | Retrospective review (after full data available) |
| Data required | Clinical signs and symptoms only | Clinical data + lab results, cultures, and imaging |
| Threshold | Minimum to justify starting antibiotics | Minimum to define a confirmed infection |
| Who uses it | Nurses and prescribers at the bedside | IPC Lead/infection control team |
| Clinical role | Supports immediate treatment decisions | Supports reporting, benchmarking, and trend analysis |
| Key limitation | Loeb supports timely decisions but still requires clinical judgement, especially where sepsis or serious deterioration is suspected. | Not designed to guide prescribing decisions |
Where It Gets Complicated - The UTI Problem
Urinary tract infections (UTIs) are where both criteria are most frequently misapplied - and
where the consequences for residents are most severe.
Consider these findings from research in Australian aged care:
Consider these findings from research in Australian aged care:
- UTIs defined by the McGeer criteria accounted for only 35% of all clinically diagnosed UTIs across 112 Australian aged care facilities
- In one study, of 119 UTIs diagnosed among residents over 16 months, only 7 met the McGeer surveillance definition
- Across the antibiotic courses reviewed, only 23% met both Loeb and McGeer criteria
- This tells us that clinicians are regularly prescribing antibiotics for UTIs that don't meet
either the minimum clinical threshold (Loeb) or the surveillance definition (McGeer).
Why? Because common, but unreliable, indicators such as foul-smelling urine, a positive
urinalysis, or behavioural changes are prompting antibiotic prescriptions, even when
standardised criteria are not met. Widespread asymptomatic bacteriuria among aged
care residents makes this even more complex, particularly for residents living with
dementia who cannot reliably report symptoms such as dysuria or urgency.
Misapplying McGeer as a prescribing guide or using Loeb to count "true infections" in your surveillance data distorts both clinical care and your facility's infection data. Both errors carry real risk.
Also worth noting meeting the McGeer criteria does not automatically mean an antibiotic is warranted, and failing to meet the Loeb criteria does not always mean no infection is present. Clinical judgement remains essential.
Misapplying McGeer as a prescribing guide or using Loeb to count "true infections" in your surveillance data distorts both clinical care and your facility's infection data. Both errors carry real risk.
Also worth noting meeting the McGeer criteria does not automatically mean an antibiotic is warranted, and failing to meet the Loeb criteria does not always mean no infection is present. Clinical judgement remains essential.
Why This Matters Right Now in Australia and New Zealand
Under the Strengthened Aged Care Quality Standards, Aged Care Act 2025 and the Aged
Care Rules 2025, antimicrobial stewardship (AMS) is now a formal requirement for all
Australian residential aged care providers. The Aged Care Quality and Safety Commission
(ACQSC) expects facilities to have structured AMS programs with clear processes for the
appropriate use of antibiotics.
In Aotearoa New Zealand, Health New Zealand, Te Whatu Ora and the Health Quality & Safety Commission (HQSC) are similarly focused on reducing unnecessary antimicrobial prescribing in residential care settings.
Knowing which tool to use - and when - is no longer optional. It's part of safe, compliant, and resident-centred care.
In Aotearoa New Zealand, Health New Zealand, Te Whatu Ora and the Health Quality & Safety Commission (HQSC) are similarly focused on reducing unnecessary antimicrobial prescribing in residential care settings.
Knowing which tool to use - and when - is no longer optional. It's part of safe, compliant, and resident-centred care.
Quick References for Your Team
- Use Loeb when: a resident shows signs of possible infection and a prescriber needs to decide whether to start antibiotics - right now, before any results are back.
- Use McGeer when: your IPC Lead is reviewing infection data, completing line lists, reporting to management, or benchmarking infection rates across your facility.
- Never use Loeb to count infections for surveillance. Never use McGeer as a bedside prescribing checklist.
- Getting this right means fewer unnecessary antibiotics, better outcomes for residents,
and a stronger antimicrobial stewardship program - one that stands up to scrutiny
under the strengthened aged care standards.
Takeaway Message:
Use Loeb to support real-time antibiotic decision-making, and McGeer to apply consistent
surveillance definitions. Neither replaces clinical judgement, escalation pathways, or local
prescribing guidance.
Sources:
Loeb M et al., Infect Control Hosp Epidemiol, 2001;
Stone ND et al., Infect Control Hosp Epidemiol, 2012;
ACSQHC Antimicrobial Use Report, August 2025;
Aged Care National Antimicrobial Prescribing Survey;
Infections in Australian Aged-Care Facilities: Evaluating the Impact of Revised McGeer
Criteria (Cambridge Core, 2016);
Infection Control Today, January/February 2025.
Loeb M et al., Infect Control Hosp Epidemiol, 2001;
Stone ND et al., Infect Control Hosp Epidemiol, 2012;
ACSQHC Antimicrobial Use Report, August 2025;
Aged Care National Antimicrobial Prescribing Survey;
Infections in Australian Aged-Care Facilities: Evaluating the Impact of Revised McGeer
Criteria (Cambridge Core, 2016);
Infection Control Today, January/February 2025.
For more blogs on topics you suggest, see the HUB, or ask EVE for that quick, tricky question.
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Lyndon Forrest
Managing Director | CEO
Lyndon is the Managing Director of Infection Prevention Services (IPS), bringing over 30 years' experience supporting aged care providers across Australia and New Zealand.
With a background spanning outbreak response, compliance, and infection risk management — alongside hands-on experience leading teams, managing multi-site operations, and navigating business turnaround — he understands both the clinical and organisational pressures aged care providers face. Lyndon holds a Master of Commerce (Industrial Relations), and applies that foundation to the people, process, and growth challenges that come with running a complex healthcare services business.
He is passionate about building the systems and capability that make infection prevention sustainable — not just compliant — and about helping organisations grow their confidence alongside their practice.
Lyndon's focus is straightforward: strengthen operations, develop the right people, and drive proactive infection prevention strategies that protect residents, staff, and communities for the long term.
Lyndon is the Managing Director of Infection Prevention Services (IPS), bringing over 30 years' experience supporting aged care providers across Australia and New Zealand.
With a background spanning outbreak response, compliance, and infection risk management — alongside hands-on experience leading teams, managing multi-site operations, and navigating business turnaround — he understands both the clinical and organisational pressures aged care providers face. Lyndon holds a Master of Commerce (Industrial Relations), and applies that foundation to the people, process, and growth challenges that come with running a complex healthcare services business.
He is passionate about building the systems and capability that make infection prevention sustainable — not just compliant — and about helping organisations grow their confidence alongside their practice.
Lyndon's focus is straightforward: strengthen operations, develop the right people, and drive proactive infection prevention strategies that protect residents, staff, and communities for the long term.
Erica Callaghan
Marketing Manager
Erica Callaghan is a dedicated professional with a rich background in agriculture and nutrient management. Growing up on her family's farm in Mid Canterbury, she developed a deep passion for farming. She currently resides on her partner's arable property in South Canterbury.
In 2017, Erica joined the Farm Sustainability team, focusing on nutrient management and environmental stewardship. In February 2024, she became the Manager of Marketing and Sales at Bug Control New Zealand - Infection Prevention Services, where her passion now includes improving infection prevention outcomes.
Outside of work, Erica loves cooking and traveling, often combining her culinary interests with her explorations in Italy and Vietnam. She enjoys entertaining family and friends and remains actively involved in farm activities, especially during harvest season.
Erica Callaghan is a dedicated professional with a rich background in agriculture and nutrient management. Growing up on her family's farm in Mid Canterbury, she developed a deep passion for farming. She currently resides on her partner's arable property in South Canterbury.
In 2017, Erica joined the Farm Sustainability team, focusing on nutrient management and environmental stewardship. In February 2024, she became the Manager of Marketing and Sales at Bug Control New Zealand - Infection Prevention Services, where her passion now includes improving infection prevention outcomes.
Outside of work, Erica loves cooking and traveling, often combining her culinary interests with her explorations in Italy and Vietnam. She enjoys entertaining family and friends and remains actively involved in farm activities, especially during harvest season.
Toni Sherriff
Clinical Nurse Specialist
Toni is a Registered Nurse with extensive experience in Infection Prevention and Control. Her career began as a kitchen hand and caregiver in Aged Care facilities, followed by earning a Bachelor of Nursing.
Toni has significant experience, having worked in Brisbane’s Infectious Diseases ward before returning home to New Zealand, where she continued her career as a Clinical Nurse Specialist in Infection Prevention and Control within Te Whatu Ora (Health NZ).
Toni brings her expertise and dedication to our team, which is instrumental in providing top-tier infection prevention solutions to our clients.
Toni is a Registered Nurse with extensive experience in Infection Prevention and Control. Her career began as a kitchen hand and caregiver in Aged Care facilities, followed by earning a Bachelor of Nursing.
Toni has significant experience, having worked in Brisbane’s Infectious Diseases ward before returning home to New Zealand, where she continued her career as a Clinical Nurse Specialist in Infection Prevention and Control within Te Whatu Ora (Health NZ).
Toni brings her expertise and dedication to our team, which is instrumental in providing top-tier infection prevention solutions to our clients.
Julie Hadfield
Accounts & Payroll
Julie is experienced in Accounts & Payroll Administration & after a long career in both the Financial & Local Government Sectors, is now working with our team. Julie brings her strong time management & organisational skills to our team, which is important to keep the company running in the background to enable the rest of our team to provide top notch service to all of our clients.
Julie is experienced in Accounts & Payroll Administration & after a long career in both the Financial & Local Government Sectors, is now working with our team. Julie brings her strong time management & organisational skills to our team, which is important to keep the company running in the background to enable the rest of our team to provide top notch service to all of our clients.
Andrea Murray
Content Editor
I attended Otago University in NZ and graduated as a Dental Surgeon. After 40 years in the profession, I retired in 2022. Infection prevention knowledge was part of everyday practice, dealing with sterilisation, hand hygiene, and cleaning.
Before retiring, I began doing some editing and proofreading for Bug Control as I am interested in the subject and in the English language. During the COVID-19 lockdown, I attended the ACIPC course "Introduction to Infection Prevention and Control", which increased my interest in the subject. I now work part-time as the Content Editor for the company.
I attended Otago University in NZ and graduated as a Dental Surgeon. After 40 years in the profession, I retired in 2022. Infection prevention knowledge was part of everyday practice, dealing with sterilisation, hand hygiene, and cleaning.
Before retiring, I began doing some editing and proofreading for Bug Control as I am interested in the subject and in the English language. During the COVID-19 lockdown, I attended the ACIPC course "Introduction to Infection Prevention and Control", which increased my interest in the subject. I now work part-time as the Content Editor for the company.
Personally, I lived in the UK for 10 years. My two children were born in Scotland, and now both are living in Europe, one in Amsterdam, Netherlands, and the other in Edinburgh, Scotland. I live close to Fairlie on the South Island of NZ, a beautiful part of the country, and I love being out of the city.
Princess
Customer Support
Princess began her career as a dedicated Customer Service Representative, honing her communication and problem-solving skills. She later transitioned into a Literary Specialist role, where she developed a keen eye for detail. Her journey then led her to a Sales Specialist position, where she excelled in client relations.
Now, as a Customer Support professional in Infection Prevention Services. Princess focuses on ensuring customer satisfaction, building loyalty, and enhancing the overall customer journey.
Princess began her career as a dedicated Customer Service Representative, honing her communication and problem-solving skills. She later transitioned into a Literary Specialist role, where she developed a keen eye for detail. Her journey then led her to a Sales Specialist position, where she excelled in client relations.
Now, as a Customer Support professional in Infection Prevention Services. Princess focuses on ensuring customer satisfaction, building loyalty, and enhancing the overall customer journey.
Dianne Newey
Senior Infection Prevention and Control Consultant
Dianne is a Senior Clinical Consultant at Infection Prevention Services (IPS), bringing over 35 years of nursing experience and a depth of clinical knowledge that most people would need two careers to accumulate.
Having served as Clinical Director at Royal Ryde Rehabilitation Hospital alongside a career spanning the full breadth of clinical practice, Dianne has seen it all — and more importantly, knows exactly what to do about it. She is the person in the room that everyone quietly hopes will speak first.
For more than seven years she has been a cornerstone of the IPS team, providing clinical advice, developing and reviewing policies and procedures, delivering monthly IPC webinars to IP Leads, and conducting environmental audits in aged care facilities across Australia and New Zealand. If infection prevention has a question, Dianne almost certainly has the answer — and she'll deliver it with a laugh that you'll hear from the other end of the corridor.
A true fountain of knowledge, wrapped in the kind of warmth and humour that only three decades of nursing can produce. Customers don't just trust Dianne — they look forward to hearing from her.
Dianne is a Senior Clinical Consultant at Infection Prevention Services (IPS), bringing over 35 years of nursing experience and a depth of clinical knowledge that most people would need two careers to accumulate.
Having served as Clinical Director at Royal Ryde Rehabilitation Hospital alongside a career spanning the full breadth of clinical practice, Dianne has seen it all — and more importantly, knows exactly what to do about it. She is the person in the room that everyone quietly hopes will speak first.
For more than seven years she has been a cornerstone of the IPS team, providing clinical advice, developing and reviewing policies and procedures, delivering monthly IPC webinars to IP Leads, and conducting environmental audits in aged care facilities across Australia and New Zealand. If infection prevention has a question, Dianne almost certainly has the answer — and she'll deliver it with a laugh that you'll hear from the other end of the corridor.
A true fountain of knowledge, wrapped in the kind of warmth and humour that only three decades of nursing can produce. Customers don't just trust Dianne — they look forward to hearing from her.
Caoimhe (Keva) Stewart
Clinical & Business Operations Manager
Caoimhe is the Clinical & Business Operations Manager at Infection Prevention Services (IPS), bringing a clinical background as a Registered Nurse across the UK and Australia — and an almost unsettling ability to make technology do exactly what she wants.
With experience in Occupational Health, Palliative Care, and Community Nursing, she understands the real challenges faced by healthcare teams. What she may lack in stature she more than makes up for in impact — Caoimhe is the kind of person who walks into a problem, sizes it up, and has three solutions before anyone else has finished reading the brief.
Customers love her. Not just because she delivers — though she always does — but because she genuinely cares about the outcome on the other side. She is passionate about creating seamless learning experiences and empowering organisations with the tools, knowledge, and support needed to strengthen infection prevention practices and improve care outcomes.
Small in size. Mighty in results. Completely irreplaceable.
Caoimhe is the Clinical & Business Operations Manager at Infection Prevention Services (IPS), bringing a clinical background as a Registered Nurse across the UK and Australia — and an almost unsettling ability to make technology do exactly what she wants.
With experience in Occupational Health, Palliative Care, and Community Nursing, she understands the real challenges faced by healthcare teams. What she may lack in stature she more than makes up for in impact — Caoimhe is the kind of person who walks into a problem, sizes it up, and has three solutions before anyone else has finished reading the brief.
Customers love her. Not just because she delivers — though she always does — but because she genuinely cares about the outcome on the other side. She is passionate about creating seamless learning experiences and empowering organisations with the tools, knowledge, and support needed to strengthen infection prevention practices and improve care outcomes.
Small in size. Mighty in results. Completely irreplaceable.
Bridgette Mackie
Clinical Nurse Educator
Bridgette is an experienced New Zealand Registered Nurse, qualified Healthcare Auditor, and Healthcare Educator with a strong background in clinical quality, competency assessment, and infection prevention. She has led large-scale OSCE and CAP training programmes for internationally qualified nurses, developed sector-specific educational resources, and coordinated HealthCERT audit preparation in the surgical sector.
Known for her engaging teaching style and genuine passion for supporting learners, Bridgette excels at making complex topics accessible and relevant. She blends operational leadership with a deep commitment to professional development and safe, effective practice.
Bridgette is an experienced New Zealand Registered Nurse, qualified Healthcare Auditor, and Healthcare Educator with a strong background in clinical quality, competency assessment, and infection prevention. She has led large-scale OSCE and CAP training programmes for internationally qualified nurses, developed sector-specific educational resources, and coordinated HealthCERT audit preparation in the surgical sector.
Known for her engaging teaching style and genuine passion for supporting learners, Bridgette excels at making complex topics accessible and relevant. She blends operational leadership with a deep commitment to professional development and safe, effective practice.
