Differential Diagnosis for Post-Transplant Fever

Single Most Likely Diagnosis

• Cytomegalovirus (CMV): CMV is a common cause of infection in transplant recipients, particularly in the first few weeks after transplantation. The risk is higher in seronegative recipients who receive an organ from a seropositive donor, but it can also reactivate in seropositive recipients due to immunosuppression.

Other Likely Diagnoses

• Candida albicans: Candida infections are common in immunocompromised patients, especially those who have undergone recent surgery or have been on broad-spectrum antibiotics. The risk is higher in liver transplant patients due to potential breaches in sterile technique during surgery and the use of central venous catheters.
• Staphylococcus aureus: Staphylococcus aureus can cause a variety of infections, including pneumonia, bacteremia, and surgical site infections, which are relevant in the post-transplant period. The use of central lines and surgical interventions increases the risk.

Do Not Miss Diagnoses

• Pneumocystis jiroveci: Although less common in the immediate post-transplant period, Pneumocystis jiroveci pneumonia (PCP) is a critical diagnosis not to miss due to its high mortality rate if untreated. Prophylaxis is often given to transplant patients, but breakthrough infections can occur.

Rare Diagnoses

• Other opportunistic infections and rare bacterial or fungal pathogens could be considered, but they are less likely given the timeframe and clinical context provided. The focus should remain on the more common pathogens listed above, with a broadening of the differential diagnosis if initial evaluations are negative.