Antimicrobial Awareness Week

Meet Manny. Manny is a microbe.

He's been introduced to his person and is having a fantastic time – he's growing and replicating and getting strong. However, his person isn't doing great. His person is starting to feel really unwell – dizzy, lightheaded, increasing urinary frequency and back pain. The skin surrounding their surgical wound is starting to get a bit red and itchy. Manny's person has had some samples taken from them – to see what's making them sick.

His person has sepsis. Sepsis is the immune system's response to an infection which causes the body to attack its own tissues and organs and is a medical emergency.

It can occur in response to any bacterial, viral or fungal infection acquired in a community or healthcare setting. If sepsis is not treated quickly, it can lead to organ failure and death. The international clinical definition of sepsis is 'life-threatening organ dysfunction caused by a dysregulated host response to infection¹. When treating patients for sepsis, ensure you utilise evidence-based guidelines such as the Therapeutic Guidelines accessible via CIAP or locally endorsed guidelines. Antibiotic choice is determined by the most likely source of sepsis.

The new national Sepsis Clinical Care Standard, launched on 30 June 2022, will help to ensure sepsis is recognised early and patients receive coordinated, best-practice care so that the risk of death or ongoing morbidity is reduced. This includes timely recognition of sepsis, early and appropriate antimicrobial therapy and continuity of care from the acute setting through to discharge and survivorship.

The CEC has developed the following resource in relation to sepsis:

Sepsis Pathways

A set of standardised sepsis tools that have been developed in consultation with NSW Health frontline clinicians and other experts.

References

1. Singer, M, Deutschmann, C, Seymour, C, et al., 2016, 'The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)', Journal of the American Medical Association, Feb 23; 315(8) 801-810.

Manny and his toxins

Manny is really enjoying his time with his person; he doesnt want to leave! However, his persons liver is helping to neutralise the toxins Manny produces. The liver is the main organ that removes toxins from your body. Manny starts to replicate to overcome being removed by his person's liver and immune system.

Many bacteria produce toxins, and in some cases, more than one toxin is produced by a microorganism. For example, toxins that induce abnormal platelet activation, leading to formation of platelet aggregates and occlusion of small vessels. Or toxins that induce haemolysis via activation of internal apoptosis pathways that cause cell death¹. Some even modulate the immune response to help the bacteria evade usual protection systems and continue to cause illness².

The toxins produced by microorganisms can contribute to the clinical deterioration of patients with sepsis. Between the Flags (BTF) is a 'deteriorating patient safety net system' for patients who are cared for in NSW public health facilities. It is designed to assist clinicians to recognise when patients are deteriorating and to respond appropriately when they do.

See the Between the Flags webpage for more information.

References

1. Kwiecinski, J M, Horswill, A R, 2020, 'Staphylococcus aureus bloodstream infections: pathogenesis and regulatory mechanisms' Curr Opin Microbiol, Feb; 53: 51–60.
2. Forbes, J D, 2020, 'Clinically Important Toxins in Bacterial Infection: Utility of Laboratory Detection', Clinical Microbiology Newsletter, Oct 15; 42(20): 163–170

Importance of Cultures

Manny's person has had some samples taken from them – to see what's making them sick.

Blood cultures are the 'gold standard' for the detection of microbial pathogens related to bacteraemia and sepsis¹ – but make sure you get enough! Adequate volume of blood is needed to be able to culture bacteria and fungi. A minimum of two (2) sets are recommended for adequate volume.^2,3

Blood cultures enable the detection of bacteria, viruses and/or fungus in the blood and guide the appropriate selection of antimicrobials.^1,2 Accuracy of test results rely on correct blood volume to improve confirmation of bacteraemia, viremia or fungaemia and minimise the risk of contamination.

Always use aseptic technique when collecting samples – the correct sample collection technique may help reduce the risk of cross contamination and a false positive test result – and ensure hand hygiene is performed.^1-4

In patients with a central venous access device (CVAD) and suspected sepsis, one set of blood cultures should be taken from the CVAD as well as one set from a peripheral site.⁵

See the Hand Hygiene webpage for more information.

The CEC has developed the following resources in relation to blood cultures:

• CEC Adult Blood Culture Guidance
• CEC Paediatric Blood Culture Guideline
• CEC Neonatal Blood Culture Guideline

References

1. Fabre V, Sharara SL, Salinas AB, et al. Does This Patient Need Blood Cultures? A Scoping Review of Indications for Blood Cultures in Adult Nonneutropenic Inpatients. Clin Infect Dis 2020; 71:1339.
2. Cheng MP, Stenstrom R, Paquette K, et al. Blood Culture Results Before and After Antimicrobial Administration in Patients With Severe Manifestations of Sepsis: A Diagnostic Study. Ann Intern Med 2019; 171:547
3. Clinical Excellence Commission. Healthcare Associated Infection (HAI) Clinical Indicator Manual. Version 3.2. December 2020.
4. Infection Prevention and Control Policy (PD2017_013)
5. Intravascular Access Devices (IVAD) - Infection Prevention & Control (PD2019_040)

Microbial Identification

The results are in! Manny is a strain of staphylococcus called methicillin resistant Staphylococcus aureus (MRSA).

Staphylococcus aureus are common bacteria. Staphylococcus species are usually harmless, and many healthy people carry these bacteria on their skin or in their nose. However, sometimes they can cause infection and illness. Some strains of staphylococcus are resistant to the antibiotic called methicillin, and to other antibiotics. These strains are known as methicillin resistant Staphylococcus aureus (MRSA).

MRSA can live in lots of different places. Manny doesn't remember how he got introduced to his person, but he doesn't mind. He never wants to leave! He might have been introduced to his person at home, or in his person's community. He might even have been introduced to his person at the hospital when his person was having a minor operation!

If he was introduced to his person at the hospital, that would mean his episode with his person is a Hospital Acquired Infection (HAI).

Manny's person will need antibiotics.

The CEC has developed resources for patients receiving antibiotics in hospital, and their carers:

• Receiving Antibiotics in Hospital - Information for Patients and Carers (this resource is translated into several languages for CALD patients)
• Receiving Antibiotics in Hospital (D/L format). Information for Patients and Carers
• Do you have a true antibiotic allergy?
• Do you have an antibiotic allergy?
• Changing from intravenous to oral antibiotics

Appropriate therapy

Appropriate antibiotics will treat infections caused by bacteria, like Manny.

However, antibiotics don't work against viruses.

Manny's person will feel better after taking the right antibiotics. Use evidence-based guidelines for empirical therapy, such as the Therapeutic Guidelines accessible via CIAP, or local evidence based guidelines. Directing therapy when culture reports are available is the gold standard for antimicrobial therapy.

Antimicrobials are amongst the most commonly prescribed medications. Misuse or unnecessary use of antimicrobials has consequences for patients and the community. Selecting and using antibiotics appropriately helps preserve these medications and prevent the development of antimicrobial resistance.

Antimicrobial stewardship programs are designed to optimise antimicrobial use – using the narrowest spectrum therapy where possible, in safe and effective doses, limiting duration to what is needed according to evidence and avoiding use where there is no evidence of benefit.

The CEC has developed the following resources for AMS programs and surgical antimicrobial prophylaxis:

• AMS homepage
• Surgical Antimicrobial Prophylaxis resources
• Emerging pathogens resources

For further information or advice about promoting Antimicrobial Awareness Week in NSW public hospitals, please send us an email.