Microbiology referrals are primarily for advice on infection management, including antibiotic choice, duration, and need for further investigations or source control. Before calling, ensure you’ve reviewed the patient’s clinical picture, current and previous microbiology results, and recent antibiotic use. Microbiology advice is most useful when you can provide clear context – the site of infection, severity, and any complicating factors such as immunosuppression or indwelling devices. Always have the culture results, sensitivities, and antibiotic history to hand, as well as relevant imaging and surgical input if applicable. A well-prepared referral helps tailor therapy appropriately and avoids unnecessary broad-spectrum antibiotic use.
- What to Take Into Account Before Referring
-Stabilise the patient first – if septic or acutely unwell, start empiric antibiotics and escalate clinically before calling.
-Check local antibiotic guidelines before referring as many questions are already covered.
-Review the patient’s clinical background, likely source of infection, and any recent or current antibiotics.
-Check microbiology results (blood, urine, sputum, wound, CSF, line, etc.) and sensitivities before calling.
-Ensure source control has been addressed (e.g. abscess drained, line removed, surgical review).
Have ready:
-Patient identifiers (name, age, location, hospital number).
-Site/source and duration of infection.
-Observations and NEWS2 score.
-All recent antibiotics as well as doses and durations.
-Culture results and sensitivities (or when cultures were taken).
-Relevant PMH: immunosuppression, diabetes, renal disease.
-Recent procedures, imaging, or indwelling devices.
-Drug allergies.
- What to Refer to Microbiology
Appropriate referrals:
-Resistant organisms (MRSA, ESBL, VRE, CPE, Pseudomonas, Candida).
-Persistent infection or lack of clinical response to appropriate antibiotics.
-Bacteraemia or fungaemia, especially Staph aureus, Enterococcus, or Candida.
-Endocarditis or suspected endovascular infection.
-Prosthetic / device-related infection (valves, joints, pacemakers, lines).
-Deep-seated infection (abscess, osteomyelitis).
-Neutropenic or immunocompromised patients with infection.
-Recurrent or severe C. difficile.
-Tuberculosis or atypical mycobacterial infections (liaise with ID/TB team).
-Infection in pregnancy.
Common premature or unnecessary referrals:
-Routine CAP, UTI, cellulitis – follow local empiric guidelines.
-Early sepsis (e.g <24h on antibiotics) – review after initial response.
-Line or drain management issues – should be discussed with surgical/medical team first.
- Common referrals
Bacteraemia (especially Staph aureus or Candida):
-Organism and sensitivities.
-Possible source (line, urine, wound).
-Blood culture timing and repeats.
-Any echo or imaging done.
-Lines or prostheses present.
Current antibiotics and start date.
Endocarditis:
-Organism (if known) or suspected source.
-Blood cultures and timing.
-Echo results (TTE/TOE).
-Antibiotic regimen and duration so far.
Line-related infection:
-Type of line and insertion date.
-Cultures (peripheral vs line tip).
-Local signs (erythema, discharge).
-Has the line been removed or replaced?
-Current antibiotics.
Bone/joint infection / prosthetic joint:
-Imaging findings (X-ray, MRI).
-Organism (if isolated).
-Surgical input or plans.
-Duration of infection.
-Antibiotic course to date.
Intra-abdominal abscess or collection:
-Source (diverticular, post-op, etc.).
-Drain in situ? Fluid cultured?
-Antibiotics given and response.
-Imaging findings (CT, USS).
C. difficile / antibiotic-associated diarrhoea:
-Stool test results and toxin status.
-Current antibiotics and duration.
-Previous episodes of C. diff.
-Hydration and renal status.
Neutropenic or immunosuppressed patient:
-Neutrophil count.
-Source suspected.
-Cultures taken.
-Antibiotics started and time given.
-Response to therapy so far.
Multi-drug resistant infection (ESBL, MRSA, etc.):
-Organism and full sensitivity pattern.
-Site of infection.
-Comorbidities (esp. renal function).
-Current and previous antibiotics.
Post-surgical wound infection:
-Procedure type and date.
-Swab or culture results.
-Systemic symptoms (fever, sepsis).
-Drain in place? Source controlled?
-Current therapy.
Complex / recurrent UTI:
-Urine culture results.
-Previous organisms and sensitivities.
-Catheter use or stent present?
-Antibiotics already tried.
-Renal function.
