Antimicrobial stewardship foundations

Microbes are microscopic organisms; in infection discussions the term also commonly includes viruses, which need host cells to reproduce. Bacteria, fungi, viruses and microscopic parasites differ in structure and behaviour. Many microbes live on or in the body without causing disease. Some contribute to normal functions, such as the activity of gut microbial communities. Others can cause infection, depending on the organism, body site and person’s circumstances.

Colonization describes the presence of organisms without the same meaning as symptomatic infection. A positive result therefore needs interpretation in clinical context; this course does not authorize a learner to diagnose or dismiss an infection. Changes in the person’s condition must still be reported and assessed through the appropriate route.

Fictional exercise: a colleague says that every bacterium in the body must be removed. Explain why that statement is inaccurate, then distinguish the general concept from a real person’s test result, which needs clinical interpretation. Do not recommend a probiotic or treatment from this general lesson.

Practice: Create a concept map with microbes, normal microbial communities, colonization and infection. Add one question that must be referred to a clinician rather than answered from the map.

Antimicrobial is an umbrella term. Antibiotics target bacteria; antivirals target viruses; antifungals target fungi; antiparasitic medicines target parasites. Medicines within a class are not interchangeable, and no medicine treats every organism in its broad group. The choice depends on the suspected or identified infection and the person’s circumstances, assessed by the appropriate prescriber.

Fictional matching exercise: connect a bacterial infection with the antibiotic category, a viral infection with the antiviral category, a fungal infection with the antifungal category and a parasitic infection with the antiparasitic category. This establishes vocabulary, not a treatment recommendation. Not every infection requires a medicine from the corresponding category.

An antibiotic used for a previous illness is not a general remedy for a new symptom. Do not share, select, start, stop or change medicines based on this activity. Follow the authorized care plan and ask the prescriber or pharmacist about uncertainties.

Practice: Write four fictional organism-category cards and match them to the four medicine classes. Add the limitation that the match alone does not determine treatment.

Resistance means that a microbe can withstand a medicine that would otherwise be expected to act against it. Genetic changes can arise, and bacteria can also acquire resistance genes from other bacteria. Exposure to an antimicrobial can favour survival and spread of resistant organisms. It is inaccurate to say simply that the patient’s body has become resistant to the antibiotic.

Responsible use means using antimicrobials when clinically indicated and following current prescribed instructions. Prevention also matters: appropriate hand hygiene, vaccination where indicated, infection-prevention measures and safe handling of medicines can reduce infections and transmission. Prescribers and stewardship teams review choices using clinical information; a support worker must not independently alter treatment to attempt to reduce resistance.

Fictional exercise: someone proposes saving part of a prescription to share later. Explain that another person’s illness and treatment needs may differ, and direct questions about use, unwanted effects or disposal to the appropriate clinician or pharmacist. Do not give an inflexible instruction to continue a medicine despite a serious reaction; urgent symptoms require appropriate urgent help.

Practice: Explain selection in a fictional population of susceptible and resistant microbes. Identify two prevention actions within your role and two decisions requiring a prescriber or pharmacist.

Resistant infections may be harder to treat, require different or more complex treatment and increase illness, deaths and resource demands. Reliable infection treatment also supports surgery and other care in which infection is a major risk. The consequences therefore extend beyond the original infection or the person first exposed.

Microbes and resistance can move through people, animals and the environment. A One Health approach considers these connections rather than treating human medicine as an isolated system. Canadian surveillance and coordinated action help identify trends and guide responses; this lesson does not substitute for current local guidance or resistance data.

Fictional planning exercise: a care team considers resistance only a hospital problem. Identify how community prevention, appropriate prescribing, transitions between services and communication of relevant information also matter. Avoid blaming individuals or communities for a global problem. Use respectful, evidence-based discussion and the organization’s infection-prevention process.

Practice: Draw three connected settings—community, hospital and environment—and explain why prevention and appropriate use cannot be confined to one setting. State a limitation of your simple diagram.

Antibiotics do not act against viruses. Some infections improve without an antimicrobial, and unnecessary treatment can expose a person to adverse effects and contribute to resistance without useful benefit. Conversely, some infections need prompt specific treatment. The decision requires clinical assessment; a learner must not decide from this course that a particular person should go untreated.

A clinician may recommend supportive care, monitoring and clear instructions about when to seek reassessment. Not prescribing an antibiotic is not the same as ignoring symptoms. Check that the person understands the plan and knows the relevant follow-up or urgent-help route. Report deterioration or concerns promptly through the appropriate process.

Fictional scenario: a person asks a care worker to obtain leftover antibiotics for a new cough. The worker should not diagnose the cause or supply another person’s medicine. Help the person access appropriate assessment and explain that antibiotics are not a universal treatment. Follow the actual clinician’s plan rather than a generic course rule.

Practice: Practise a response to the fictional request that avoids diagnosis, discourages sharing medicines and supports appropriate assessment and follow-up.