Synopsis
Use transplant timing and net immunosuppression to recognise ordinary and opportunistic infection, protect graft function, obtain decisive samples and coordinate antimicrobial and immunosuppressive treatment.
- In the first month, prioritise donor-derived, surgical, device-associated and healthcare-acquired infection, including wound, anastomotic, urinary, pulmonary, bloodstream and intra-abdominal sources.
- From roughly one to six months, viral reactivation and opportunists become prominent: CMV, EBV, BK polyomavirus, Pneumocystis, Aspergillus, Candida, nocardia, toxoplasma and tuberculosis depend on organ, serostatus and prophylaxis.
- After six months, stable recipients mainly acquire community infections, while chronic graft dysfunction or intensified immunosuppression sustains late opportunistic risk.
- Timing is a map, not a rule: prophylaxis delays disease, rejection therapy moves the patient back into a high-risk phase and donor or geographic exposures create exceptions.
- First-line assessment combines cultures, graft-function tests, medication levels and syndrome-directed imaging; add quantitative viral testing and tissue sampling according to the immune defect.
- Treat severe undifferentiated infection promptly with the locally approved, source-based regimen informed by previous colonisation and prophylaxis; narrow when cultures or molecular results define the cause.
- Never adjust tacrolimus, ciclosporin, mycophenolate or corticosteroids casually during infection; antimicrobial interactions, rejection risk and immune restoration require transplant-pharmacy and transplant-team control.
- CMV QNAT is the standard blood monitoring method, but proven tissue-invasive disease may require histology with viral demonstration; isolated DNAaemia is not synonymous with organ disease.
Key red flags
Hypotension, rising lactate, confusion, oliguria or increasing oxygen need requires immediate sepsis treatment even when fever and CRP are modest.
New graft pain, falling urine output, cholestasis, cardiac dysfunction or deteriorating spirometry may represent infection, rejection, obstruction or vascular compromise and needs same-day transplant assessment.
Severe headache, altered behaviour, seizure or focal neurology raises concern for cryptococcosis, nocardiosis, mould infection, toxoplasmosis, bacterial infection or post-transplant lymphoproliferative disorder.
Haemoptysis, pleuritic pain, nodules, cavities or diffuse hypoxaemia requires rapid CT-based evaluation for mould, Pneumocystis, nocardia, CMV and bacterial disease.
Diarrhoea with dehydration, abdominal pain or graft-drug toxicity can rapidly destabilise calcineurin-inhibitor exposure and renal function.
Recent rejection treatment, lymphocyte-depleting therapy, lapse of prophylaxis or donor-derived infection warning resets risk regardless of the calendar time since transplant.
Wound change, line symptoms, urinary obstruction, bile leak, anastomotic pain, collection or ventilator-associated disease within the first month points toward surgical and healthcare pathogens.
Investigation priorities
Define severity, recover bacteria and detect organ or graft dysfunction before therapy reduces diagnostic yield.
Management branches
A transplant recipient has shock, organ dysfunction, hypoxaemia or another severe infection phenotype.
- Perform ABCDE, obtain cultures and urgent laboratory tests, then start the locally approved source-based intravenous regimen without waiting for transfer or specialist arrival.
- Use prior susceptibility, current prophylaxis, organ type, time after transplant and healthcare exposure to identify resistant Gram-negative, enterococcal, staphylococcal and fungal gaps.
- Contact the implanting or responsible transplant service, microbiology and critical care; arrange drainage, device removal or surgical assessment when anatomy drives sepsis.
- Continue essential corticosteroid coverage and ask the transplant team to direct any reduction of antiproliferative or calcineurin therapy.
The patient is stable enough for a structured diagnostic search after immediate threats are addressed.
- Within one month, inspect wound, drains, lines and anastomoses and investigate donor-derived or nosocomial infection before attributing illness to a late opportunist.
- From one to six months, test for CMV and organ-specific viruses and investigate Pneumocystis, mould, nocardia, mycobacteria and toxoplasma according to symptoms, serostatus and prophylaxis.